奇安信攻防社区-安卓学习思路方法总结（五）

安卓学习思路方法总结（五）

分享者才是学习中最大的受益者

JNI
===

JNI是Java Native Interface的缩写，通过使用 [Java](https://baike.baidu.com/item/Java/85979)本地接口书写程序，可以确保代码在不同的平台上方便移植。

从Java1.1开始，JNI标准成为java平台的一部分，它允许Java代码和其他语言写的[代码](https://baike.baidu.com/item/%E4%BB%A3%E7%A0%81/86048)进行交互。JNI一开始是为了本地已[编译](https://baike.baidu.com/item/%E7%BC%96%E8%AF%91/1258343)语言，尤其是C和C++而设计的，但是它并不妨碍你使用其他编程语言，只要调用约定受支持就可以了。

使用java与本地已编译的代码[交互](https://baike.baidu.com/item/%E4%BA%A4%E4%BA%92/6964417)，通常会丧失平台[可移植性](https://baike.baidu.com/item/%E5%8F%AF%E7%A7%BB%E6%A4%8D%E6%80%A7/6931884)。但是，有些情况下这样做是可以接受的，甚至是必须的。

JNI的接口就是一些函数的API

### JNI接口

Java语言发展到现在已经经历了20多年，其语言框架本身已经非常成熟，而且整个生态都保持得非常好，因而再与底层的C、甚至汇编进行辅助的话，那就能释放出更强大的威力来。而Java要与本地底层代码进行交互，则需要通过`JNI(Java Native Interface)`接口

### JNI作用

![image-20210812132234704](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812132234704.png)

JN接口是处在Java层和C/C++层之间，承担桥梁作用

1、通过JN接口实现Java层与 Native层相互调用  
2、JNI接口中的类型

```php
1、调用java层普通方法-CallObjectMethod

2、获取Java层实例字段的值-GetMethodID

3、获取Java层实例字段的值

4、设置Java层实例字段的值

5、调用Java层静态方法

6、获取Java层静态字段的值

7、设置Java层静态宇段的值

8、New开头的函数就是创建
```

```php
get 获取
set 设置
call 调用
```

### CallObjectMethod

调用一个方法，返回值是 Object

void是表示返回值为空！所以使用的方法就是构建参数后面三个参数

#### JNIEnv\*

```php
默认参数

动态调试经常用到，本地调用的一个接口，提供了大量的jni接口函数去调用

可以理解为JNI默认传入的参数型
```

#### jobject

```php
也是默认参数
```

#### jmethodID

CallObjectMethod运行操作时的一个方法ID，用来获取java层方法的ID

在这之前 要先使用，使用`GetMethodID`方法获取方法ID，作为返回值

### GetMethodID

它是获取Java层实例字段的值`GetMethodID`

```php
jmethodID (*GetMethodID)(JNIEnv*, jclass, const char*, const char*);
```

1、`JNIEnv`：默认参数！  
2）`jclass`：一个 findclass引用  
这里的返回值和jclass目的是一样的，jclass这个参数是由findclass返回值获取的

3、`const char*`：参数列表信息3）const char:Java层方法的名称  
4、`const char*`：Java层方法的一个签名，是返回值+参数

### 获取Java层实例字段的值

```php
jobject (*GetObjectField)(JNIEnv*, jobject, jfieldID);
```

获取jfieldID的获取

```php
jfieldID (*GetFieldID)(JNIEnv*, jclass, const char*, const char*);
```

### 设置Java层实例字段的值

```php
void (*SetObjectField)(JNIEnv*, jobject, jfieldID, jobject);
```

jfeldID是 GetFieldID的返回值！  
jobject是一个java层实例字段设置的值！

NDK
===

Eclipse快速创建项目
-------------

这个 我们之前 有提到过

这里就快速过

![](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/202108121801416.png)

![image-20210812180217575](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812180217575.png)

![image-20210812180240336](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812180240336.png)

![image-20210812180323169](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812180323169.png)

![image-20210812180344424](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812180344424.png)

![image-20210812180429143](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812180429143.png)

![image-20210812180614473](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812180614473.png)

![image-20210812182808692](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812182808692.png)

静态注册(一)
-------

在Java层使用jni接口获取C层定义的一个字符

定位`MainActivity.java`

上一节[安卓学习思路方法总结（四）](https://www.freebuf.com/articles/mobile/284486.html)讲到JNI和c的联动

创建JNI的文件夹

然后三个文件：`aaa.c`、`Application.mk`、`Android.mk`

然后在JNI目录下进行：`ndk-build`编译

![image-20210812135357852](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/202108121659162.png)

继续

这一块时安卓 后期界面的显示

先删掉

![image-20210812194132765](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812194132765.png)

### 定义一个方法

```php
public native CharSequence Getstring();
```

![image-20210812200105803](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812200105803.png)

在java层使用JDG反编译的时候是看不到它的逻辑代码，只能看到空荡荡的一个方法名，而且这个方法的具体实现在java层是看不到的

掌握ndk开发的知识，在so程序找到它对应的一个`.so`文件，然后去分析它的一个逻辑

### 区分动态注册！

动态注册会使用到`JNI_onload`类里面有个注册函数；

这里已经定义了一个被native修饰的方法，那么修饰这个方法就要做一些操作，在java层用 Toast展示出来

```php
Toast.makeTest(context,text,duration);
```

![image-20210812200248765](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812200248765.png)

```php
context:上下文text:弹出的内容字符duration:显示的一个时长
```

然后进行修改

```php
context->this上下文text->方法Getstring()duration->Toast.LENGTH_SHORT
```

进行显示

```php
.show()
```

```php
Toast.makeText(this,Getstring(),Toast.LENGTH_SHORT).show();
```

![image-20210812195740331](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812195740331.png)

### 获取src目录

![](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812200610213.png)

```php
D:\data\aaa\src
```

![image-20210812200630982](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812200630982.png)

### 获取完整路径

被`native`修饰的一个方法 `Getstring()`所在的一个类的完整的路径

![image-20210812201323490](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812201323490.png)

```php
com.example.aaa.MainActivity
```

![image-20210812201251156](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812201251156.png)

### javah

使用javah命令

![image-20210812200750394](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812200750394.png)

我们底层调用的头文件`.h`就是JNI样式的标头文件

```php
javah -jni com.example.aaa.MainActivity
```

![image-20210812210650157](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812210650157.png)

### Refresh

![image-20210812210738450](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812210738450.png)

在src目录生成`.h`的头文件

![image-20210812210811988](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812210811988.png)

进行分析

![image-20210812211054865](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812211054865.png)

```php
JNIEXPORT->标识符jobject ->返回值JNICALL->标识符
```

### 万能表

```php
#ifndef JNI_H_
#define JNI_H_

#include <sys/cdefs.h>
#include <stdarg.h>

#ifdef HAVE_INTTYPES_H
# include <inttypes.h>      /* C99 */
    //这个是JNI规范中定义的基本数据类型
    //typedef 关键字，可以使用它来为类型取一个新的名字。
    //举个例子：typedef unsigned char BYTE;在这个类型定义之后，标识符 BYTE 可作为类型 unsigned char 的缩写
typedef uint8_t         jboolean;       /* unsigned 8 bits */
typedef int8_t          jbyte;          /* signed 8 bits */
typedef uint16_t        jchar;          /* unsigned 16 bits */
typedef int16_t         jshort;         /* signed 16 bits */
typedef int32_t         jint;           /* signed 32 bits */
typedef int64_t         jlong;          /* signed 64 bits */
typedef float           jfloat;         /* 32-bit IEEE 754 */
typedef double          jdouble;        /* 64-bit IEEE 754 */
#else
typedef unsigned char   jboolean;       /* unsigned 8 bits */
typedef signed char     jbyte;          /* signed 8 bits */
typedef unsigned short  jchar;          /* unsigned 16 bits */
typedef short           jshort;         /* signed 16 bits */
typedef int             jint;           /* signed 32 bits */
typedef long long       jlong;          /* signed 64 bits */
typedef float           jfloat;         /* 32-bit IEEE 754 */
typedef double          jdouble;        /* 64-bit IEEE 754 */
#endif

/* "cardinal indices and sizes" */
typedef jint            jsize;          //表示返回数组的大小

#ifdef __cplusplus
/*
 * Reference types, in C++          //与C++有关的定义
 */
class _jobject {};
class _jclass : public _jobject {};
class _jstring : public _jobject {};
class _jarray : public _jobject {};
class _jobjectArray : public _jarray {};
class _jbooleanArray : public _jarray {};
class _jbyteArray : public _jarray {};
class _jcharArray : public _jarray {};
class _jshortArray : public _jarray {};
class _jintArray : public _jarray {};
class _jlongArray : public _jarray {};
class _jfloatArray : public _jarray {};
class _jdoubleArray : public _jarray {};
class _jthrowable : public _jobject {};
            //为C++的一些类型进行重新定义
typedef _jobject*       jobject;
typedef _jclass*        jclass;
typedef _jstring*       jstring;
typedef _jarray*        jarray;
typedef _jobjectArray*  jobjectArray;
typedef _jbooleanArray* jbooleanArray;
typedef _jbyteArray*    jbyteArray;
typedef _jcharArray*    jcharArray;
typedef _jshortArray*   jshortArray;
typedef _jintArray*     jintArray;
typedef _jlongArray*    jlongArray;
typedef _jfloatArray*   jfloatArray;
typedef _jdoubleArray*  jdoubleArray;
typedef _jthrowable*    jthrowable;
typedef _jobject*       jweak;

#else /* not __cplusplus */

/*
 * Reference types, in C.           //与C有关的，继续为类型起新的名字；有arrary表示按JNI 标准定义的数组类型
 */

typedef void*           jobject;
typedef jobject         jclass;
typedef jobject         jstring;
typedef jobject         jarray;
typedef jarray          jobjectArray;
typedef jarray          jbooleanArray;
typedef jarray          jbyteArray;
typedef jarray          jcharArray;
typedef jarray          jshortArray;
typedef jarray          jintArray;
typedef jarray          jlongArray;
typedef jarray          jfloatArray;
typedef jarray          jdoubleArray;
typedef jobject         jthrowable;
typedef jobject         jweak;

#endif /* not __cplusplus */
                //两个方法ID和字段ID
struct _jfieldID;                       /* opaque structure */
typedef struct _jfieldID* jfieldID;     /* field IDs */

struct _jmethodID;                      /* opaque structure */
typedef struct _jmethodID* jmethodID;   /* method IDs */

//定义一个结构体JNIInvokeInterface，是一个调用接口的结构体
struct JNIInvokeInterface; 
                //定义一个联合体jvalue，里面有各种类型
typedef union jvalue {
    jboolean    z;
    jbyte       b;
    jchar       c;
    jshort      s;
    jint        i;
    jlong       j;
    jfloat      f;
    jdouble     d;
    jobject     l;
} jvalue;
                //定义一个枚举jobjectRefType，里面有各种枚举元素
typedef enum jobjectRefType {
    JNIInvalidRefType = 0,
    JNILocalRefType = 1,
    JNIGlobalRefType = 2,
    JNIWeakGlobalRefType = 3
} jobjectRefType;

//定义一个动态注册JNINativeMethod结构体，这个与动态注册有关，里面有三个元素
typedef struct {
    const char* name; //第一个参数 name 是java 方法名；
    const char* signature; //第二个参数 signature 用于描述方法的参数与返回值，也就是java方法签名信息，
    void*       fnPtr; //第三个参数 fnPtr 是函数指针，指向 jni 函数；
} JNINativeMethod;

//      其中，第二个参数 signature 使用字符串记录方法的参数与返回值，具体格式形如“()V”、“(II)V”，其中分为两部分，括号内表示的是参数，括号右侧表示的是返回值；

struct _JNIEnv;
struct _JavaVM;
            //定义一个JNINativeInterface结构体，表示原生调用接口的结构体
typedef const struct JNINativeInterface* C_JNIEnv;

#if defined(__cplusplus)
typedef _JNIEnv JNIEnv;
typedef _JavaVM JavaVM;
#else
                    //这里有两个接口，一个是本地接口，一个是调用接口
typedef const struct JNINativeInterface* JNIEnv;//JNI本地接口
typedef const struct JNIInvokeInterface* JavaVM;//JNI调用接口
#endif
        //本地接口结构体的定义
struct JNINativeInterface {
    void*       reserved0;
    void*       reserved1;
    void*       reserved2;
    void*       reserved3;

jint        (*GetVersion)(JNIEnv *);        //jint返回的是版本信息

//jclass，返回的是类

jclass      (*DefineClass)(JNIEnv*, const char*, jobject, const jbyte*,jsize);
    jclass      (*FindClass)(JNIEnv*, const char*);

jmethodID   (*FromReflectedMethod)(JNIEnv*, jobject);
    jfieldID    (*FromReflectedField)(JNIEnv*, jobject);

jobject     (*ToReflectedMethod)(JNIEnv*, jclass, jmethodID, jboolean);
    jclass      (*GetSuperclass)(JNIEnv*, jclass);
    jboolean    (*IsAssignableFrom)(JNIEnv*, jclass, jclass);

jobject     (*ToReflectedField)(JNIEnv*, jclass, jfieldID, jboolean);
                //与异常有关的方法
    jint        (*Throw)(JNIEnv*, jthrowable);
    jint        (*ThrowNew)(JNIEnv *, jclass, const char *);
    jthrowable  (*ExceptionOccurred)(JNIEnv*);
    void        (*ExceptionDescribe)(JNIEnv*);
    void        (*ExceptionClear)(JNIEnv*);
    void        (*FatalError)(JNIEnv*, const char*);

jint        (*PushLocalFrame)(JNIEnv*, jint);
    jobject     (*PopLocalFrame)(JNIEnv*, jobject);

jobject     (*NewGlobalRef)(JNIEnv*, jobject);
    void        (*DeleteGlobalRef)(JNIEnv*, jobject);
    void        (*DeleteLocalRef)(JNIEnv*, jobject);
    jboolean    (*IsSameObject)(JNIEnv*, jobject, jobject);

jobject     (*NewLocalRef)(JNIEnv*, jobject);
    jint        (*EnsureLocalCapacity)(JNIEnv*, jint);
                //新建object
    jobject     (*AllocObject)(JNIEnv*, jclass);
    jobject     (*NewObject)(JNIEnv*, jclass, jmethodID, ...);
    jobject     (*NewObjectV)(JNIEnv*, jclass, jmethodID, va_list);
    jobject     (*NewObjectA)(JNIEnv*, jclass, jmethodID, jvalue*);

jclass      (*GetObjectClass)(JNIEnv*, jobject);
    jboolean    (*IsInstanceOf)(JNIEnv*, jobject, jclass);
    jmethodID   (*GetMethodID)(JNIEnv*, jclass, const char*, const char*);
                    //调用方法
    jobject     (*CallObjectMethod)(JNIEnv*, jobject, jmethodID, ...);
    jobject     (*CallObjectMethodV)(JNIEnv*, jobject, jmethodID, va_list);
    jobject     (*CallObjectMethodA)(JNIEnv*, jobject, jmethodID, jvalue*);
    jboolean    (*CallBooleanMethod)(JNIEnv*, jobject, jmethodID, ...);
    jboolean    (*CallBooleanMethodV)(JNIEnv*, jobject, jmethodID, va_list);
    jboolean    (*CallBooleanMethodA)(JNIEnv*, jobject, jmethodID, jvalue*);
    jbyte       (*CallByteMethod)(JNIEnv*, jobject, jmethodID, ...);
    jbyte       (*CallByteMethodV)(JNIEnv*, jobject, jmethodID, va_list);
    jbyte       (*CallByteMethodA)(JNIEnv*, jobject, jmethodID, jvalue*);
    jchar       (*CallCharMethod)(JNIEnv*, jobject, jmethodID, ...);
    jchar       (*CallCharMethodV)(JNIEnv*, jobject, jmethodID, va_list);
    jchar       (*CallCharMethodA)(JNIEnv*, jobject, jmethodID, jvalue*);
    jshort      (*CallShortMethod)(JNIEnv*, jobject, jmethodID, ...);
    jshort      (*CallShortMethodV)(JNIEnv*, jobject, jmethodID, va_list);
    jshort      (*CallShortMethodA)(JNIEnv*, jobject, jmethodID, jvalue*);
    jint        (*CallIntMethod)(JNIEnv*, jobject, jmethodID, ...);
    jint        (*CallIntMethodV)(JNIEnv*, jobject, jmethodID, va_list);
    jint        (*CallIntMethodA)(JNIEnv*, jobject, jmethodID, jvalue*);
    jlong       (*CallLongMethod)(JNIEnv*, jobject, jmethodID, ...);
    jlong       (*CallLongMethodV)(JNIEnv*, jobject, jmethodID, va_list);
    jlong       (*CallLongMethodA)(JNIEnv*, jobject, jmethodID, jvalue*);
    jfloat      (*CallFloatMethod)(JNIEnv*, jobject, jmethodID, ...) __NDK_FPABI__;
    jfloat      (*CallFloatMethodV)(JNIEnv*, jobject, jmethodID, va_list) __NDK_FPABI__;
    jfloat      (*CallFloatMethodA)(JNIEnv*, jobject, jmethodID, jvalue*) __NDK_FPABI__;
    jdouble     (*CallDoubleMethod)(JNIEnv*, jobject, jmethodID, ...) __NDK_FPABI__;
    jdouble     (*CallDoubleMethodV)(JNIEnv*, jobject, jmethodID, va_list) __NDK_FPABI__;
    jdouble     (*CallDoubleMethodA)(JNIEnv*, jobject, jmethodID, jvalue*) __NDK_FPABI__;
    void        (*CallVoidMethod)(JNIEnv*, jobject, jmethodID, ...);
    void        (*CallVoidMethodV)(JNIEnv*, jobject, jmethodID, va_list);
    void        (*CallVoidMethodA)(JNIEnv*, jobject, jmethodID, jvalue*);

jobject     (*CallNonvirtualObjectMethod)(JNIEnv*, jobject, jclass, jmethodID, ...);
    jobject     (*CallNonvirtualObjectMethodV)(JNIEnv*, jobject, jclass,jmethodID, va_list);
    jobject     (*CallNonvirtualObjectMethodA)(JNIEnv*, jobject, jclass,jmethodID, jvalue*);
    jboolean    (*CallNonvirtualBooleanMethod)(JNIEnv*, jobject, jclass,jmethodID, ...);
    jboolean    (*CallNonvirtualBooleanMethodV)(JNIEnv*, jobject, jclass,jmethodID, va_list);
    jboolean    (*CallNonvirtualBooleanMethodA)(JNIEnv*, jobject, jclass,jmethodID, jvalue*);
    jbyte       (*CallNonvirtualByteMethod)(JNIEnv*, jobject, jclass,jmethodID, ...);
    jbyte       (*CallNonvirtualByteMethodV)(JNIEnv*, jobject, jclass,jmethodID, va_list);
    jbyte       (*CallNonvirtualByteMethodA)(JNIEnv*, jobject, jclass,jmethodID, jvalue*);
    jchar       (*CallNonvirtualCharMethod)(JNIEnv*, jobject, jclass,jmethodID, ...);
    jchar       (*CallNonvirtualCharMethodV)(JNIEnv*, jobject, jclass,jmethodID, va_list);
    jchar       (*CallNonvirtualCharMethodA)(JNIEnv*, jobject, jclass, jmethodID, jvalue*);
    jshort      (*CallNonvirtualShortMethod)(JNIEnv*, jobject, jclass, jmethodID, ...);
    jshort      (*CallNonvirtualShortMethodV)(JNIEnv*, jobject, jclass,jmethodID, va_list);
    jshort      (*CallNonvirtualShortMethodA)(JNIEnv*, jobject, jclass,jmethodID, jvalue*);
    jint        (*CallNonvirtualIntMethod)(JNIEnv*, jobject, jclass,jmethodID, ...);
    jint        (*CallNonvirtualIntMethodV)(JNIEnv*, jobject, jclass,jmethodID, va_list);
    jint        (*CallNonvirtualIntMethodA)(JNIEnv*, jobject, jclass,jmethodID, jvalue*);
    jlong       (*CallNonvirtualLongMethod)(JNIEnv*, jobject, jclass,jmethodID, ...);
    jlong       (*CallNonvirtualLongMethodV)(JNIEnv*, jobject, jclass,jmethodID, va_list);
    jlong       (*CallNonvirtualLongMethodA)(JNIEnv*, jobject, jclass,jmethodID, jvalue*);
    jfloat      (*CallNonvirtualFloatMethod)(JNIEnv*, jobject, jclass,jmethodID, ...) __NDK_FPABI__;
    jfloat      (*CallNonvirtualFloatMethodV)(JNIEnv*, jobject, jclass,jmethodID, va_list) __NDK_FPABI__;
    jfloat      (*CallNonvirtualFloatMethodA)(JNIEnv*, jobject, jclass, jmethodID, jvalue*) __NDK_FPABI__;
    jdouble     (*CallNonvirtualDoubleMethod)(JNIEnv*, jobject, jclass,jmethodID, ...) __NDK_FPABI__;
    jdouble     (*CallNonvirtualDoubleMethodV)(JNIEnv*, jobject, jclass,jmethodID, va_list) __NDK_FPABI__;
    jdouble     (*CallNonvirtualDoubleMethodA)(JNIEnv*, jobject, jclass,jmethodID, jvalue*) __NDK_FPABI__;
    void        (*CallNonvirtualVoidMethod)(JNIEnv*, jobject, jclass,jmethodID, ...);
    void        (*CallNonvirtualVoidMethodV)(JNIEnv*, jobject, jclass,jmethodID, va_list);
    void        (*CallNonvirtualVoidMethodA)(JNIEnv*, jobject, jclass,jmethodID, jvalue*);

//获取各种字段
    jfieldID    (*GetFieldID)(JNIEnv*, jclass, const char*, const char*);

jobject     (*GetObjectField)(JNIEnv*, jobject, jfieldID);
    jboolean    (*GetBooleanField)(JNIEnv*, jobject, jfieldID);
    jbyte       (*GetByteField)(JNIEnv*, jobject, jfieldID);
    jchar       (*GetCharField)(JNIEnv*, jobject, jfieldID);
    jshort      (*GetShortField)(JNIEnv*, jobject, jfieldID);
    jint        (*GetIntField)(JNIEnv*, jobject, jfieldID);
    jlong       (*GetLongField)(JNIEnv*, jobject, jfieldID);
    jfloat      (*GetFloatField)(JNIEnv*, jobject, jfieldID) __NDK_FPABI__;
    jdouble     (*GetDoubleField)(JNIEnv*, jobject, jfieldID) __NDK_FPABI__;
                    //设置各种字段，返回为空
    void        (*SetObjectField)(JNIEnv*, jobject, jfieldID, jobject);
    void        (*SetBooleanField)(JNIEnv*, jobject, jfieldID, jboolean);
    void        (*SetByteField)(JNIEnv*, jobject, jfieldID, jbyte);
    void        (*SetCharField)(JNIEnv*, jobject, jfieldID, jchar);
    void        (*SetShortField)(JNIEnv*, jobject, jfieldID, jshort);
    void        (*SetIntField)(JNIEnv*, jobject, jfieldID, jint);
    void        (*SetLongField)(JNIEnv*, jobject, jfieldID, jlong);
    void        (*SetFloatField)(JNIEnv*, jobject, jfieldID, jfloat) __NDK_FPABI__;
    void        (*SetDoubleField)(JNIEnv*, jobject, jfieldID, jdouble) __NDK_FPABI__;

jmethodID   (*GetStaticMethodID)(JNIEnv*, jclass, const char*, const char*);

jobject     (*CallStaticObjectMethod)(JNIEnv*, jclass, jmethodID, ...);
    jobject     (*CallStaticObjectMethodV)(JNIEnv*, jclass, jmethodID, va_list);
    jobject     (*CallStaticObjectMethodA)(JNIEnv*, jclass, jmethodID, jvalue*);
    jboolean    (*CallStaticBooleanMethod)(JNIEnv*, jclass, jmethodID, ...);
    jboolean    (*CallStaticBooleanMethodV)(JNIEnv*, jclass, jmethodID,va_list);
    jboolean    (*CallStaticBooleanMethodA)(JNIEnv*, jclass, jmethodID,jvalue*);
    jbyte       (*CallStaticByteMethod)(JNIEnv*, jclass, jmethodID, ...);
    jbyte       (*CallStaticByteMethodV)(JNIEnv*, jclass, jmethodID, va_list);
    jbyte       (*CallStaticByteMethodA)(JNIEnv*, jclass, jmethodID, jvalue*);
    jchar       (*CallStaticCharMethod)(JNIEnv*, jclass, jmethodID, ...);
    jchar       (*CallStaticCharMethodV)(JNIEnv*, jclass, jmethodID, va_list);
    jchar       (*CallStaticCharMethodA)(JNIEnv*, jclass, jmethodID, jvalue*);
    jshort      (*CallStaticShortMethod)(JNIEnv*, jclass, jmethodID, ...);
    jshort      (*CallStaticShortMethodV)(JNIEnv*, jclass, jmethodID, va_list);
    jshort      (*CallStaticShortMethodA)(JNIEnv*, jclass, jmethodID, jvalue*);
    jint        (*CallStaticIntMethod)(JNIEnv*, jclass, jmethodID, ...);
    jint        (*CallStaticIntMethodV)(JNIEnv*, jclass, jmethodID, va_list);
    jint        (*CallStaticIntMethodA)(JNIEnv*, jclass, jmethodID, jvalue*);
    jlong       (*CallStaticLongMethod)(JNIEnv*, jclass, jmethodID, ...);
    jlong       (*CallStaticLongMethodV)(JNIEnv*, jclass, jmethodID, va_list);
    jlong       (*CallStaticLongMethodA)(JNIEnv*, jclass, jmethodID, jvalue*);
    jfloat      (*CallStaticFloatMethod)(JNIEnv*, jclass, jmethodID, ...) __NDK_FPABI__;
    jfloat      (*CallStaticFloatMethodV)(JNIEnv*, jclass, jmethodID, va_list) __NDK_FPABI__;
    jfloat      (*CallStaticFloatMethodA)(JNIEnv*, jclass, jmethodID, jvalue*) __NDK_FPABI__;
    jdouble     (*CallStaticDoubleMethod)(JNIEnv*, jclass, jmethodID, ...) __NDK_FPABI__;
    jdouble     (*CallStaticDoubleMethodV)(JNIEnv*, jclass, jmethodID, va_list) __NDK_FPABI__;
    jdouble     (*CallStaticDoubleMethodA)(JNIEnv*, jclass, jmethodID, jvalue*) __NDK_FPABI__;
    void        (*CallStaticVoidMethod)(JNIEnv*, jclass, jmethodID, ...);
    void        (*CallStaticVoidMethodV)(JNIEnv*, jclass, jmethodID, va_list);
    void        (*CallStaticVoidMethodA)(JNIEnv*, jclass, jmethodID, jvalue*);

jfieldID    (*GetStaticFieldID)(JNIEnv*, jclass, const char*,const char*);

jobject     (*GetStaticObjectField)(JNIEnv*, jclass, jfieldID);
    jboolean    (*GetStaticBooleanField)(JNIEnv*, jclass, jfieldID);
    jbyte       (*GetStaticByteField)(JNIEnv*, jclass, jfieldID);
    jchar       (*GetStaticCharField)(JNIEnv*, jclass, jfieldID);
    jshort      (*GetStaticShortField)(JNIEnv*, jclass, jfieldID);
    jint        (*GetStaticIntField)(JNIEnv*, jclass, jfieldID);
    jlong       (*GetStaticLongField)(JNIEnv*, jclass, jfieldID);
    jfloat      (*GetStaticFloatField)(JNIEnv*, jclass, jfieldID) __NDK_FPABI__;
    jdouble     (*GetStaticDoubleField)(JNIEnv*, jclass, jfieldID) __NDK_FPABI__;

void        (*SetStaticObjectField)(JNIEnv*, jclass, jfieldID, jobject);
    void        (*SetStaticBooleanField)(JNIEnv*, jclass, jfieldID, jboolean);
    void        (*SetStaticByteField)(JNIEnv*, jclass, jfieldID, jbyte);
    void        (*SetStaticCharField)(JNIEnv*, jclass, jfieldID, jchar);
    void        (*SetStaticShortField)(JNIEnv*, jclass, jfieldID, jshort);
    void        (*SetStaticIntField)(JNIEnv*, jclass, jfieldID, jint);
    void        (*SetStaticLongField)(JNIEnv*, jclass, jfieldID, jlong);
    void        (*SetStaticFloatField)(JNIEnv*, jclass, jfieldID, jfloat) __NDK_FPABI__;
    void        (*SetStaticDoubleField)(JNIEnv*, jclass, jfieldID, jdouble) __NDK_FPABI__;

jstring     (*NewString)(JNIEnv*, const jchar*, jsize);
    jsize       (*GetStringLength)(JNIEnv*, jstring);
    const jchar*(*GetStringChars)(JNIEnv*, jstring, jboolean*);
    void        (*ReleaseStringChars)(JNIEnv*, jstring, const jchar*);
    jstring     (*NewStringUTF)(JNIEnv*, const char*);
    jsize       (*GetStringUTFLength)(JNIEnv*, jstring);

const char* (*GetStringUTFChars)(JNIEnv*, jstring, jboolean*);
    void        (*ReleaseStringUTFChars)(JNIEnv*, jstring, const char*);
    jsize       (*GetArrayLength)(JNIEnv*, jarray);
    jobjectArray(*NewObjectArray)(JNIEnv*, jsize, jclass, jobject);
    jobject     (*GetObjectArrayElement)(JNIEnv*, jobjectArray, jsize);
    void        (*SetObjectArrayElement)(JNIEnv*, jobjectArray, jsize, jobject);

jbooleanArray (*NewBooleanArray)(JNIEnv*, jsize);
    jbyteArray    (*NewByteArray)(JNIEnv*, jsize);
    jcharArray    (*NewCharArray)(JNIEnv*, jsize);
    jshortArray   (*NewShortArray)(JNIEnv*, jsize);
    jintArray     (*NewIntArray)(JNIEnv*, jsize);
    jlongArray    (*NewLongArray)(JNIEnv*, jsize);
    jfloatArray   (*NewFloatArray)(JNIEnv*, jsize);
    jdoubleArray  (*NewDoubleArray)(JNIEnv*, jsize);

jboolean*   (*GetBooleanArrayElements)(JNIEnv*, jbooleanArray, jboolean*);
    jbyte*      (*GetByteArrayElements)(JNIEnv*, jbyteArray, jboolean*);
    jchar*      (*GetCharArrayElements)(JNIEnv*, jcharArray, jboolean*);
    jshort*     (*GetShortArrayElements)(JNIEnv*, jshortArray, jboolean*);
    jint*       (*GetIntArrayElements)(JNIEnv*, jintArray, jboolean*);
    jlong*      (*GetLongArrayElements)(JNIEnv*, jlongArray, jboolean*);
    jfloat*     (*GetFloatArrayElements)(JNIEnv*, jfloatArray, jboolean*);
    jdouble*    (*GetDoubleArrayElements)(JNIEnv*, jdoubleArray, jboolean*);

void        (*ReleaseBooleanArrayElements)(JNIEnv*, jbooleanArray,jboolean*, jint);
    void        (*ReleaseByteArrayElements)(JNIEnv*, jbyteArray,jbyte*, jint);
    void        (*ReleaseCharArrayElements)(JNIEnv*, jcharArray,jchar*, jint);
    void        (*ReleaseShortArrayElements)(JNIEnv*, jshortArray,jshort*, jint);
    void        (*ReleaseIntArrayElements)(JNIEnv*, jintArray,jint*, jint);
    void        (*ReleaseLongArrayElements)(JNIEnv*, jlongArray,jlong*, jint);
    void        (*ReleaseFloatArrayElements)(JNIEnv*, jfloatArray,jfloat*, jint);
    void        (*ReleaseDoubleArrayElements)(JNIEnv*, jdoubleArray,jdouble*, jint);

void        (*GetBooleanArrayRegion)(JNIEnv*, jbooleanArray,jsize,jsize, jboolean*);
    void        (*GetByteArrayRegion)(JNIEnv*, jbyteArray,jsize, jsize,jbyte*);
    void        (*GetCharArrayRegion)(JNIEnv*, jcharArray, jsize, jsize,jchar*);
    void        (*GetShortArrayRegion)(JNIEnv*, jshortArray,jsize, jsize,jshort*);
    void        (*GetIntArrayRegion)(JNIEnv*, jintArray,jsize, jsize, jint*);
    void        (*GetLongArrayRegion)(JNIEnv*, jlongArray,jsize, jsize, jlong*);
    void        (*GetFloatArrayRegion)(JNIEnv*, jfloatArray,jsize, jsize, jfloat*);
    void        (*GetDoubleArrayRegion)(JNIEnv*, jdoubleArray,jsize, jsize, jdouble*);

void        (*SetBooleanArrayRegion)(JNIEnv*, jbooleanArray,jsize, jsize, const jboolean*);
    void        (*SetByteArrayRegion)(JNIEnv*, jbyteArray,jsize, jsize, const jbyte*);
    void        (*SetCharArrayRegion)(JNIEnv*, jcharArray,jsize, jsize, const jchar*);
    void        (*SetShortArrayRegion)(JNIEnv*, jshortArray,jsize, jsize, const jshort*);
    void        (*SetIntArrayRegion)(JNIEnv*, jintArray,jsize, jsize, const jint*);
    void        (*SetLongArrayRegion)(JNIEnv*, jlongArray, jsize, jsize, const jlong*);
    void        (*SetFloatArrayRegion)(JNIEnv*, jfloatArray, jsize, jsize, const jfloat*);
    void        (*SetDoubleArrayRegion)(JNIEnv*, jdoubleArray,jsize, jsize, const jdouble*);

jint        (*RegisterNatives)(JNIEnv*, jclass, const JNINativeMethod*,jint);
    jint        (*UnregisterNatives)(JNIEnv*, jclass);
    jint        (*MonitorEnter)(JNIEnv*, jobject);
    jint        (*MonitorExit)(JNIEnv*, jobject);
    jint        (*GetJavaVM)(JNIEnv*, JavaVM**);

void        (*GetStringRegion)(JNIEnv*, jstring, jsize, jsize, jchar*);
    void        (*GetStringUTFRegion)(JNIEnv*, jstring, jsize, jsize, char*);

void*       (*GetPrimitiveArrayCritical)(JNIEnv*, jarray, jboolean*);
    void        (*ReleasePrimitiveArrayCritical)(JNIEnv*, jarray, void*, jint);

const jchar*(*GetStringCritical)(JNIEnv*, jstring, jboolean*);
    void        (*ReleaseStringCritical)(JNIEnv*, jstring, const jchar*);

jweak       (*NewWeakGlobalRef)(JNIEnv*, jobject);
    void        (*DeleteWeakGlobalRef)(JNIEnv*, jweak);

jboolean    (*ExceptionCheck)(JNIEnv*);

jobject     (*NewDirectByteBuffer)(JNIEnv*, void*, jlong);
    void*       (*GetDirectBufferAddress)(JNIEnv*, jobject);
    jlong       (*GetDirectBufferCapacity)(JNIEnv*, jobject);

jobjectRefType (*GetObjectRefType)(JNIEnv*, jobject);
};

/*
 * C++ 
 */
            //C++的JNI 本地接口结构体的调用
struct _JNIEnv {
    const struct JNINativeInterface* functions;

#if defined(__cplusplus)
            //各种函数
    jint GetVersion()
    { return functions->GetVersion(this); }

jclass DefineClass(const char *name, jobject loader, const jbyte* buf,
        jsize bufLen)
    { return functions->DefineClass(this, name, loader, buf, bufLen); }

jclass FindClass(const char* name)
    { return functions->FindClass(this, name); }

jmethodID FromReflectedMethod(jobject method)
    { return functions->FromReflectedMethod(this, method); }

jfieldID FromReflectedField(jobject field)
    { return functions->FromReflectedField(this, field); }

jobject ToReflectedMethod(jclass cls, jmethodID methodID, jboolean isStatic)
    { return functions->ToReflectedMethod(this, cls, methodID, isStatic); }

jclass GetSuperclass(jclass clazz)
    { return functions->GetSuperclass(this, clazz); }

jboolean IsAssignableFrom(jclass clazz1, jclass clazz2)
    { return functions->IsAssignableFrom(this, clazz1, clazz2); }

jobject ToReflectedField(jclass cls, jfieldID fieldID, jboolean isStatic)
    { return functions->ToReflectedField(this, cls, fieldID, isStatic); }

jint Throw(jthrowable obj)
    { return functions->Throw(this, obj); }

jint ThrowNew(jclass clazz, const char* message)
    { return functions->ThrowNew(this, clazz, message); }

jthrowable ExceptionOccurred()
    { return functions->ExceptionOccurred(this); }

void ExceptionDescribe()
    { functions->ExceptionDescribe(this); }

void ExceptionClear()
    { functions->ExceptionClear(this); }

void FatalError(const char* msg)
    { functions->FatalError(this, msg); }

jint PushLocalFrame(jint capacity)
    { return functions->PushLocalFrame(this, capacity); }

jobject PopLocalFrame(jobject result)
    { return functions->PopLocalFrame(this, result); }

jobject NewGlobalRef(jobject obj)
    { return functions->NewGlobalRef(this, obj); }

void DeleteGlobalRef(jobject globalRef)
    { functions->DeleteGlobalRef(this, globalRef); }

void DeleteLocalRef(jobject localRef)
    { functions->DeleteLocalRef(this, localRef); }

jboolean IsSameObject(jobject ref1, jobject ref2)
    { return functions->IsSameObject(this, ref1, ref2); }

jobject NewLocalRef(jobject ref)
    { return functions->NewLocalRef(this, ref); }

jint EnsureLocalCapacity(jint capacity)
    { return functions->EnsureLocalCapacity(this, capacity); }

jobject AllocObject(jclass clazz)
    { return functions->AllocObject(this, clazz); }

jobject NewObject(jclass clazz, jmethodID methodID, ...)
    {
        va_list args;
        va_start(args, methodID);
        jobject result = functions->NewObjectV(this, clazz, methodID, args);
        va_end(args);
        return result;
    }

jobject NewObjectV(jclass clazz, jmethodID methodID, va_list args)
    { return functions->NewObjectV(this, clazz, methodID, args); }

jobject NewObjectA(jclass clazz, jmethodID methodID, jvalue* args)
    { return functions->NewObjectA(this, clazz, methodID, args); }

jclass GetObjectClass(jobject obj)
    { return functions->GetObjectClass(this, obj); }

jboolean IsInstanceOf(jobject obj, jclass clazz)
    { return functions->IsInstanceOf(this, obj, clazz); }

jmethodID GetMethodID(jclass clazz, const char* name, const char* sig)
    { return functions->GetMethodID(this, clazz, name, sig); }

#define CALL_TYPE_METHOD(_jtype, _jname)                                    \
    __NDK_FPABI__                                                           \
    _jtype Call##_jname##Method(jobject obj, jmethodID methodID, ...)       \
    {                                                                       \
        _jtype result;                                                      \
        va_list args;                                                       \
        va_start(args, methodID);                                           \
        result = functions->Call##_jname##MethodV(this, obj, methodID,      \
                    args);                                                  \
        va_end(args);                                                       \
        return result;                                                      \
    }
#define CALL_TYPE_METHODV(_jtype, _jname)                                   \
    __NDK_FPABI__                                                           \
    _jtype Call##_jname##MethodV(jobject obj, jmethodID methodID,           \
        va_list args)                                                       \
    { return functions->Call##_jname##MethodV(this, obj, methodID, args); }
#define CALL_TYPE_METHODA(_jtype, _jname)                                   \
    __NDK_FPABI__                                                           \
    _jtype Call##_jname##MethodA(jobject obj, jmethodID methodID,           \
        jvalue* args)                                                       \
    { return functions->Call##_jname##MethodA(this, obj, methodID, args); }

#define CALL_TYPE(_jtype, _jname)                                           \
    CALL_TYPE_METHOD(_jtype, _jname)                                        \
    CALL_TYPE_METHODV(_jtype, _jname)                                       \
    CALL_TYPE_METHODA(_jtype, _jname)

CALL_TYPE(jobject, Object)
    CALL_TYPE(jboolean, Boolean)
    CALL_TYPE(jbyte, Byte)
    CALL_TYPE(jchar, Char)
    CALL_TYPE(jshort, Short)
    CALL_TYPE(jint, Int)
    CALL_TYPE(jlong, Long)
    CALL_TYPE(jfloat, Float)
    CALL_TYPE(jdouble, Double)

void CallVoidMethod(jobject obj, jmethodID methodID, ...)
    {
        va_list args;
        va_start(args, methodID);
        functions->CallVoidMethodV(this, obj, methodID, args);
        va_end(args);
    }
    void CallVoidMethodV(jobject obj, jmethodID methodID, va_list args)
    { functions->CallVoidMethodV(this, obj, methodID, args); }
    void CallVoidMethodA(jobject obj, jmethodID methodID, jvalue* args)
    { functions->CallVoidMethodA(this, obj, methodID, args); }

#define CALL_NONVIRT_TYPE_METHOD(_jtype, _jname)                            \
    __NDK_FPABI__                                                           \
    _jtype CallNonvirtual##_jname##Method(jobject obj, jclass clazz,        \
        jmethodID methodID, ...)                                            \
    {                                                                       \
        _jtype result;                                                      \
        va_list args;                                                       \
        va_start(args, methodID);                                           \
        result = functions->CallNonvirtual##_jname##MethodV(this, obj,      \
                    clazz, methodID, args);                                 \
        va_end(args);                                                       \
        return result;                                                      \
    }
#define CALL_NONVIRT_TYPE_METHODV(_jtype, _jname)                           \
    __NDK_FPABI__                                                           \
    _jtype CallNonvirtual##_jname##MethodV(jobject obj, jclass clazz,       \
        jmethodID methodID, va_list args)                                   \
    { return functions->CallNonvirtual##_jname##MethodV(this, obj, clazz,   \
        methodID, args); }
#define CALL_NONVIRT_TYPE_METHODA(_jtype, _jname)                           \
    __NDK_FPABI__                                                           \
    _jtype CallNonvirtual##_jname##MethodA(jobject obj, jclass clazz,       \
        jmethodID methodID, jvalue* args)                                   \
    { return functions->CallNonvirtual##_jname##MethodA(this, obj, clazz,   \
        methodID, args); }

#define CALL_NONVIRT_TYPE(_jtype, _jname)                                   \
    CALL_NONVIRT_TYPE_METHOD(_jtype, _jname)                                \
    CALL_NONVIRT_TYPE_METHODV(_jtype, _jname)                               \
    CALL_NONVIRT_TYPE_METHODA(_jtype, _jname)

CALL_NONVIRT_TYPE(jobject, Object)
    CALL_NONVIRT_TYPE(jboolean, Boolean)
    CALL_NONVIRT_TYPE(jbyte, Byte)
    CALL_NONVIRT_TYPE(jchar, Char)
    CALL_NONVIRT_TYPE(jshort, Short)
    CALL_NONVIRT_TYPE(jint, Int)
    CALL_NONVIRT_TYPE(jlong, Long)
    CALL_NONVIRT_TYPE(jfloat, Float)
    CALL_NONVIRT_TYPE(jdouble, Double)

void CallNonvirtualVoidMethod(jobject obj, jclass clazz,
        jmethodID methodID, ...)
    {
        va_list args;
        va_start(args, methodID);
        functions->CallNonvirtualVoidMethodV(this, obj, clazz, methodID, args);
        va_end(args);
    }
    void CallNonvirtualVoidMethodV(jobject obj, jclass clazz,
        jmethodID methodID, va_list args)
    { functions->CallNonvirtualVoidMethodV(this, obj, clazz, methodID, args); }
    void CallNonvirtualVoidMethodA(jobject obj, jclass clazz,
        jmethodID methodID, jvalue* args)
    { functions->CallNonvirtualVoidMethodA(this, obj, clazz, methodID, args); }

jfieldID GetFieldID(jclass clazz, const char* name, const char* sig)
    { return functions->GetFieldID(this, clazz, name, sig); }

jobject GetObjectField(jobject obj, jfieldID fieldID)
    { return functions->GetObjectField(this, obj, fieldID); }
    jboolean GetBooleanField(jobject obj, jfieldID fieldID)
    { return functions->GetBooleanField(this, obj, fieldID); }
    jbyte GetByteField(jobject obj, jfieldID fieldID)
    { return functions->GetByteField(this, obj, fieldID); }
    jchar GetCharField(jobject obj, jfieldID fieldID)
    { return functions->GetCharField(this, obj, fieldID); }
    jshort GetShortField(jobject obj, jfieldID fieldID)
    { return functions->GetShortField(this, obj, fieldID); }
    jint GetIntField(jobject obj, jfieldID fieldID)
    { return functions->GetIntField(this, obj, fieldID); }
    jlong GetLongField(jobject obj, jfieldID fieldID)
    { return functions->GetLongField(this, obj, fieldID); }
    __NDK_FPABI__
    jfloat GetFloatField(jobject obj, jfieldID fieldID)
    { return functions->GetFloatField(this, obj, fieldID); }
    __NDK_FPABI__
    jdouble GetDoubleField(jobject obj, jfieldID fieldID)
    { return functions->GetDoubleField(this, obj, fieldID); }

void SetObjectField(jobject obj, jfieldID fieldID, jobject value)
    { functions->SetObjectField(this, obj, fieldID, value); }
    void SetBooleanField(jobject obj, jfieldID fieldID, jboolean value)
    { functions->SetBooleanField(this, obj, fieldID, value); }
    void SetByteField(jobject obj, jfieldID fieldID, jbyte value)
    { functions->SetByteField(this, obj, fieldID, value); }
    void SetCharField(jobject obj, jfieldID fieldID, jchar value)
    { functions->SetCharField(this, obj, fieldID, value); }
    void SetShortField(jobject obj, jfieldID fieldID, jshort value)
    { functions->SetShortField(this, obj, fieldID, value); }
    void SetIntField(jobject obj, jfieldID fieldID, jint value)
    { functions->SetIntField(this, obj, fieldID, value); }
    void SetLongField(jobject obj, jfieldID fieldID, jlong value)
    { functions->SetLongField(this, obj, fieldID, value); }
    __NDK_FPABI__
    void SetFloatField(jobject obj, jfieldID fieldID, jfloat value)
    { functions->SetFloatField(this, obj, fieldID, value); }
    __NDK_FPABI__
    void SetDoubleField(jobject obj, jfieldID fieldID, jdouble value)
    { functions->SetDoubleField(this, obj, fieldID, value); }

jmethodID GetStaticMethodID(jclass clazz, const char* name, const char* sig)
    { return functions->GetStaticMethodID(this, clazz, name, sig); }

#define CALL_STATIC_TYPE_METHOD(_jtype, _jname)                             \
    __NDK_FPABI__                                                           \
    _jtype CallStatic##_jname##Method(jclass clazz, jmethodID methodID,     \
        ...)                                                                \
    {                                                                       \
        _jtype result;                                                      \
        va_list args;                                                       \
        va_start(args, methodID);                                           \
        result = functions->CallStatic##_jname##MethodV(this, clazz,        \
                    methodID, args);                                        \
        va_end(args);                                                       \
        return result;                                                      \
    }
#define CALL_STATIC_TYPE_METHODV(_jtype, _jname)                            \
    __NDK_FPABI__                                                           \
    _jtype CallStatic##_jname##MethodV(jclass clazz, jmethodID methodID,    \
        va_list args)                                                       \
    { return functions->CallStatic##_jname##MethodV(this, clazz, methodID,  \
        args); }
#define CALL_STATIC_TYPE_METHODA(_jtype, _jname)                            \
    __NDK_FPABI__                                                           \
    _jtype CallStatic##_jname##MethodA(jclass clazz, jmethodID methodID,    \
        jvalue* args)                                                       \
    { return functions->CallStatic##_jname##MethodA(this, clazz, methodID,  \
        args); }

#define CALL_STATIC_TYPE(_jtype, _jname)                                    \
    CALL_STATIC_TYPE_METHOD(_jtype, _jname)                                 \
    CALL_STATIC_TYPE_METHODV(_jtype, _jname)                                \
    CALL_STATIC_TYPE_METHODA(_jtype, _jname)

CALL_STATIC_TYPE(jobject, Object)
    CALL_STATIC_TYPE(jboolean, Boolean)
    CALL_STATIC_TYPE(jbyte, Byte)
    CALL_STATIC_TYPE(jchar, Char)
    CALL_STATIC_TYPE(jshort, Short)
    CALL_STATIC_TYPE(jint, Int)
    CALL_STATIC_TYPE(jlong, Long)
    CALL_STATIC_TYPE(jfloat, Float)
    CALL_STATIC_TYPE(jdouble, Double)

void CallStaticVoidMethod(jclass clazz, jmethodID methodID, ...)
    {
        va_list args;
        va_start(args, methodID);
        functions->CallStaticVoidMethodV(this, clazz, methodID, args);
        va_end(args);
    }
    void CallStaticVoidMethodV(jclass clazz, jmethodID methodID, va_list args)
    { functions->CallStaticVoidMethodV(this, clazz, methodID, args); }
    void CallStaticVoidMethodA(jclass clazz, jmethodID methodID, jvalue* args)
    { functions->CallStaticVoidMethodA(this, clazz, methodID, args); }

jfieldID GetStaticFieldID(jclass clazz, const char* name, const char* sig)
    { return functions->GetStaticFieldID(this, clazz, name, sig); }

jobject GetStaticObjectField(jclass clazz, jfieldID fieldID)
    { return functions->GetStaticObjectField(this, clazz, fieldID); }
    jboolean GetStaticBooleanField(jclass clazz, jfieldID fieldID)
    { return functions->GetStaticBooleanField(this, clazz, fieldID); }
    jbyte GetStaticByteField(jclass clazz, jfieldID fieldID)
    { return functions->GetStaticByteField(this, clazz, fieldID); }
    jchar GetStaticCharField(jclass clazz, jfieldID fieldID)
    { return functions->GetStaticCharField(this, clazz, fieldID); }
    jshort GetStaticShortField(jclass clazz, jfieldID fieldID)
    { return functions->GetStaticShortField(this, clazz, fieldID); }
    jint GetStaticIntField(jclass clazz, jfieldID fieldID)
    { return functions->GetStaticIntField(this, clazz, fieldID); }
    jlong GetStaticLongField(jclass clazz, jfieldID fieldID)
    { return functions->GetStaticLongField(this, clazz, fieldID); }
    __NDK_FPABI__
    jfloat GetStaticFloatField(jclass clazz, jfieldID fieldID)
    { return functions->GetStaticFloatField(this, clazz, fieldID); }
    __NDK_FPABI__
    jdouble GetStaticDoubleField(jclass clazz, jfieldID fieldID)
    { return functions->GetStaticDoubleField(this, clazz, fieldID); }

void SetStaticObjectField(jclass clazz, jfieldID fieldID, jobject value)
    { functions->SetStaticObjectField(this, clazz, fieldID, value); }
    void SetStaticBooleanField(jclass clazz, jfieldID fieldID, jboolean value)
    { functions->SetStaticBooleanField(this, clazz, fieldID, value); }
    void SetStaticByteField(jclass clazz, jfieldID fieldID, jbyte value)
    { functions->SetStaticByteField(this, clazz, fieldID, value); }
    void SetStaticCharField(jclass clazz, jfieldID fieldID, jchar value)
    { functions->SetStaticCharField(this, clazz, fieldID, value); }
    void SetStaticShortField(jclass clazz, jfieldID fieldID, jshort value)
    { functions->SetStaticShortField(this, clazz, fieldID, value); }
    void SetStaticIntField(jclass clazz, jfieldID fieldID, jint value)
    { functions->SetStaticIntField(this, clazz, fieldID, value); }
    void SetStaticLongField(jclass clazz, jfieldID fieldID, jlong value)
    { functions->SetStaticLongField(this, clazz, fieldID, value); }
    __NDK_FPABI__
    void SetStaticFloatField(jclass clazz, jfieldID fieldID, jfloat value)
    { functions->SetStaticFloatField(this, clazz, fieldID, value); }
    __NDK_FPABI__
    void SetStaticDoubleField(jclass clazz, jfieldID fieldID, jdouble value)
    { functions->SetStaticDoubleField(this, clazz, fieldID, value); }

jstring NewString(const jchar* unicodeChars, jsize len)
    { return functions->NewString(this, unicodeChars, len); }

jsize GetStringLength(jstring string)
    { return functions->GetStringLength(this, string); }

const jchar* GetStringChars(jstring string, jboolean* isCopy)
    { return functions->GetStringChars(this, string, isCopy); }

void ReleaseStringChars(jstring string, const jchar* chars)
    { functions->ReleaseStringChars(this, string, chars); }

jstring NewStringUTF(const char* bytes)
    { return functions->NewStringUTF(this, bytes); }

jsize GetStringUTFLength(jstring string)
    { return functions->GetStringUTFLength(this, string); }

const char* GetStringUTFChars(jstring string, jboolean* isCopy)
    { return functions->GetStringUTFChars(this, string, isCopy); }

void ReleaseStringUTFChars(jstring string, const char* utf)
    { functions->ReleaseStringUTFChars(this, string, utf); }

jsize GetArrayLength(jarray array)
    { return functions->GetArrayLength(this, array); }

jobjectArray NewObjectArray(jsize length, jclass elementClass,
        jobject initialElement)
    { return functions->NewObjectArray(this, length, elementClass,
        initialElement); }

jobject GetObjectArrayElement(jobjectArray array, jsize index)
    { return functions->GetObjectArrayElement(this, array, index); }

void SetObjectArrayElement(jobjectArray array, jsize index, jobject value)
    { functions->SetObjectArrayElement(this, array, index, value); }

jbooleanArray NewBooleanArray(jsize length)
    { return functions->NewBooleanArray(this, length); }
    jbyteArray NewByteArray(jsize length)
    { return functions->NewByteArray(this, length); }
    jcharArray NewCharArray(jsize length)
    { return functions->NewCharArray(this, length); }
    jshortArray NewShortArray(jsize length)
    { return functions->NewShortArray(this, length); }
    jintArray NewIntArray(jsize length)
    { return functions->NewIntArray(this, length); }
    jlongArray NewLongArray(jsize length)
    { return functions->NewLongArray(this, length); }
    jfloatArray NewFloatArray(jsize length)
    { return functions->NewFloatArray(this, length); }
    jdoubleArray NewDoubleArray(jsize length)
    { return functions->NewDoubleArray(this, length); }

jboolean* GetBooleanArrayElements(jbooleanArray array, jboolean* isCopy)
    { return functions->GetBooleanArrayElements(this, array, isCopy); }
    jbyte* GetByteArrayElements(jbyteArray array, jboolean* isCopy)
    { return functions->GetByteArrayElements(this, array, isCopy); }
    jchar* GetCharArrayElements(jcharArray array, jboolean* isCopy)
    { return functions->GetCharArrayElements(this, array, isCopy); }
    jshort* GetShortArrayElements(jshortArray array, jboolean* isCopy)
    { return functions->GetShortArrayElements(this, array, isCopy); }
    jint* GetIntArrayElements(jintArray array, jboolean* isCopy)
    { return functions->GetIntArrayElements(this, array, isCopy); }
    jlong* GetLongArrayElements(jlongArray array, jboolean* isCopy)
    { return functions->GetLongArrayElements(this, array, isCopy); }
    jfloat* GetFloatArrayElements(jfloatArray array, jboolean* isCopy)
    { return functions->GetFloatArrayElements(this, array, isCopy); }
    jdouble* GetDoubleArrayElements(jdoubleArray array, jboolean* isCopy)
    { return functions->GetDoubleArrayElements(this, array, isCopy); }

void ReleaseBooleanArrayElements(jbooleanArray array, jboolean* elems,
        jint mode)
    { functions->ReleaseBooleanArrayElements(this, array, elems, mode); }
    void ReleaseByteArrayElements(jbyteArray array, jbyte* elems,
        jint mode)
    { functions->ReleaseByteArrayElements(this, array, elems, mode); }
    void ReleaseCharArrayElements(jcharArray array, jchar* elems,
        jint mode)
    { functions->ReleaseCharArrayElements(this, array, elems, mode); }
    void ReleaseShortArrayElements(jshortArray array, jshort* elems,
        jint mode)
    { functions->ReleaseShortArrayElements(this, array, elems, mode); }
    void ReleaseIntArrayElements(jintArray array, jint* elems,
        jint mode)
    { functions->ReleaseIntArrayElements(this, array, elems, mode); }
    void ReleaseLongArrayElements(jlongArray array, jlong* elems,
        jint mode)
    { functions->ReleaseLongArrayElements(this, array, elems, mode); }
    void ReleaseFloatArrayElements(jfloatArray array, jfloat* elems,
        jint mode)
    { functions->ReleaseFloatArrayElements(this, array, elems, mode); }
    void ReleaseDoubleArrayElements(jdoubleArray array, jdouble* elems,
        jint mode)
    { functions->ReleaseDoubleArrayElements(this, array, elems, mode); }

void GetBooleanArrayRegion(jbooleanArray array, jsize start, jsize len,
        jboolean* buf)
    { functions->GetBooleanArrayRegion(this, array, start, len, buf); }
    void GetByteArrayRegion(jbyteArray array, jsize start, jsize len,
        jbyte* buf)
    { functions->GetByteArrayRegion(this, array, start, len, buf); }
    void GetCharArrayRegion(jcharArray array, jsize start, jsize len,
        jchar* buf)
    { functions->GetCharArrayRegion(this, array, start, len, buf); }
    void GetShortArrayRegion(jshortArray array, jsize start, jsize len,
        jshort* buf)
    { functions->GetShortArrayRegion(this, array, start, len, buf); }
    void GetIntArrayRegion(jintArray array, jsize start, jsize len,
        jint* buf)
    { functions->GetIntArrayRegion(this, array, start, len, buf); }
    void GetLongArrayRegion(jlongArray array, jsize start, jsize len,
        jlong* buf)
    { functions->GetLongArrayRegion(this, array, start, len, buf); }
    void GetFloatArrayRegion(jfloatArray array, jsize start, jsize len,
        jfloat* buf)
    { functions->GetFloatArrayRegion(this, array, start, len, buf); }
    void GetDoubleArrayRegion(jdoubleArray array, jsize start, jsize len,
        jdouble* buf)
    { functions->GetDoubleArrayRegion(this, array, start, len, buf); }

void SetBooleanArrayRegion(jbooleanArray array, jsize start, jsize len,
        const jboolean* buf)
    { functions->SetBooleanArrayRegion(this, array, start, len, buf); }
    void SetByteArrayRegion(jbyteArray array, jsize start, jsize len,
        const jbyte* buf)
    { functions->SetByteArrayRegion(this, array, start, len, buf); }
    void SetCharArrayRegion(jcharArray array, jsize start, jsize len,
        const jchar* buf)
    { functions->SetCharArrayRegion(this, array, start, len, buf); }
    void SetShortArrayRegion(jshortArray array, jsize start, jsize len,
        const jshort* buf)
    { functions->SetShortArrayRegion(this, array, start, len, buf); }
    void SetIntArrayRegion(jintArray array, jsize start, jsize len,
        const jint* buf)
    { functions->SetIntArrayRegion(this, array, start, len, buf); }
    void SetLongArrayRegion(jlongArray array, jsize start, jsize len,
        const jlong* buf)
    { functions->SetLongArrayRegion(this, array, start, len, buf); }
    void SetFloatArrayRegion(jfloatArray array, jsize start, jsize len,
        const jfloat* buf)
    { functions->SetFloatArrayRegion(this, array, start, len, buf); }
    void SetDoubleArrayRegion(jdoubleArray array, jsize start, jsize len,
        const jdouble* buf)
    { functions->SetDoubleArrayRegion(this, array, start, len, buf); }

jint RegisterNatives(jclass clazz, const JNINativeMethod* methods,
        jint nMethods)
    { return functions->RegisterNatives(this, clazz, methods, nMethods); }

jint UnregisterNatives(jclass clazz)
    { return functions->UnregisterNatives(this, clazz); }

jint MonitorEnter(jobject obj)
    { return functions->MonitorEnter(this, obj); }

jint MonitorExit(jobject obj)
    { return functions->MonitorExit(this, obj); }

jint GetJavaVM(JavaVM** vm)
    { return functions->GetJavaVM(this, vm); }

void GetStringRegion(jstring str, jsize start, jsize len, jchar* buf)
    { functions->GetStringRegion(this, str, start, len, buf); }

void GetStringUTFRegion(jstring str, jsize start, jsize len, char* buf)
    { return functions->GetStringUTFRegion(this, str, start, len, buf); }

void* GetPrimitiveArrayCritical(jarray array, jboolean* isCopy)
    { return functions->GetPrimitiveArrayCritical(this, array, isCopy); }

void ReleasePrimitiveArrayCritical(jarray array, void* carray, jint mode)
    { functions->ReleasePrimitiveArrayCritical(this, array, carray, mode); }

const jchar* GetStringCritical(jstring string, jboolean* isCopy)
    { return functions->GetStringCritical(this, string, isCopy); }

void ReleaseStringCritical(jstring string, const jchar* carray)
    { functions->ReleaseStringCritical(this, string, carray); }

jweak NewWeakGlobalRef(jobject obj)
    { return functions->NewWeakGlobalRef(this, obj); }

void DeleteWeakGlobalRef(jweak obj)
    { functions->DeleteWeakGlobalRef(this, obj); }

jboolean ExceptionCheck()
    { return functions->ExceptionCheck(this); }

jobject NewDirectByteBuffer(void* address, jlong capacity)
    { return functions->NewDirectByteBuffer(this, address, capacity); }

void* GetDirectBufferAddress(jobject buf)
    { return functions->GetDirectBufferAddress(this, buf); }

jlong GetDirectBufferCapacity(jobject buf)
    { return functions->GetDirectBufferCapacity(this, buf); }

/* added in JNI 1.6 */
    jobjectRefType GetObjectRefType(jobject obj)
    { return functions->GetObjectRefType(this, obj); }
#endif /*__cplusplus*/
};

/*
 * JNI invocation interface.
 */
                    //调用接口结构体JNIInvokeInterface的定义
struct JNIInvokeInterface {
    void*       reserved0;
    void*       reserved1;
    void*       reserved2;

jint        (*DestroyJavaVM)(JavaVM*);
    jint        (*AttachCurrentThread)(JavaVM*, JNIEnv**, void*);
    jint        (*DetachCurrentThread)(JavaVM*);
    jint        (*GetEnv)(JavaVM*, void**, jint);
    jint        (*AttachCurrentThreadAsDaemon)(JavaVM*, JNIEnv**, void*);
};

/*
 * C++ version.
 */
struct _JavaVM {
    const struct JNIInvokeInterface* functions;

#if defined(__cplusplus)
    jint DestroyJavaVM()
    { return functions->DestroyJavaVM(this); }
    jint AttachCurrentThread(JNIEnv** p_env, void* thr_args)
    { return functions->AttachCurrentThread(this, p_env, thr_args); }
    jint DetachCurrentThread()
    { return functions->DetachCurrentThread(this); }
    jint GetEnv(void** env, jint version)
    { return functions->GetEnv(this, env, version); }
    jint AttachCurrentThreadAsDaemon(JNIEnv** p_env, void* thr_args)
    { return functions->AttachCurrentThreadAsDaemon(this, p_env, thr_args); }
#endif /*__cplusplus*/
};

struct JavaVMAttachArgs {
    jint        version;    /* must be >= JNI_VERSION_1_2 */
    const char* name;       /* NULL or name of thread as modified UTF-8 str */
    jobject     group;      /* global ref of a ThreadGroup object, or NULL */
};
typedef struct JavaVMAttachArgs JavaVMAttachArgs;

/*
 * JNI 1.2+ initialization.  (As of 1.6, the pre-1.2 structures are no
 * longer supported.)
 */
typedef struct JavaVMOption {
    const char* optionString;
    void*       extraInfo;
} JavaVMOption;

typedef struct JavaVMInitArgs {
    jint        version;    /* use JNI_VERSION_1_2 or later */

jint        nOptions;
    JavaVMOption* options;
    jboolean    ignoreUnrecognized;
} JavaVMInitArgs;

#ifdef __cplusplus
extern "C" {
#endif
/*
 * VM initialization functions.
 *
 * Note these are the only symbols exported for JNI by the VM.
 */
#if 0  /* In practice, these are not exported by the NDK so don't declare them */
jint JNI_GetDefaultJavaVMInitArgs(void*);
jint JNI_CreateJavaVM(JavaVM**, JNIEnv**, void*);
jint JNI_GetCreatedJavaVMs(JavaVM**, jsize, jsize*);
#endif

#define JNIIMPORT
#define JNIEXPORT  __attribute__ ((visibility ("default")))
#define JNICALL __NDK_FPABI__

/*
 * Prototypes for functions exported by loadable shared libs.  These are
 * called by JNI, not provided by JNI.
 */
JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM* vm, void* reserved);
JNIEXPORT void JNICALL JNI_OnUnload(JavaVM* vm, void* reserved);

#ifdef __cplusplus
}
#endif

/*
 * Manifest constants.
 */
#define JNI_FALSE   0
#define JNI_TRUE    1

#define JNI_VERSION_1_1 0x00010001
#define JNI_VERSION_1_2 0x00010002
#define JNI_VERSION_1_4 0x00010004
#define JNI_VERSION_1_6 0x00010006

#define JNI_OK          (0)         /* no error */
#define JNI_ERR         (-1)        /* generic error */
#define JNI_EDETACHED   (-2)        /* thread detached from the VM */
#define JNI_EVERSION    (-3)        /* JNI version error */

#define JNI_COMMIT      1           /* copy content, do not free buffer */
#define JNI_ABORT       2           /* free buffer w/o copying back */

#endif  /* JNI_H_ */
```

然后我们继续

![image-20210812211740195](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812211740195.png)

返回值、方法名称、参数类型

### 创建jni文件夹

![image-20210812212159567](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812212159567.png)

![image-20210812212222053](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812212222053.png)

![image-20210812212237105](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812212237105.png)

### MainActivity.h

把`MainActivity.h`更名 拖入`jni`文件夹

![image-20210812212436486](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812212436486.png)

![image-20210812212509913](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812212509913.png)

![image-20210812212536201](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812212536201.png)

### 一个`.c`文件两个`.mk`文件

![image-20210812212736407](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812212736407.png)

`.c`文件的头文件进行调用`.h`文件

![image-20210812212900421](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812212900421.png)

### 写函数

![image-20210812213322630](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812213322630.png)

返回值 参数 方法体 三个类型

只有两个参数

补充参数

![image-20210812213555345](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812213555345.png)

回显内容：return

目的：c层返回一个字符串给java层

借助JNI接口`NewStringUTF`

查万能表

```php
jstring     (*NewStringUTF)(JNIEnv*, const char*);
```

返回的是一个字符串 使用str接收

使用JNI指针类型指出

```php
jstring str = *aaa->NewStringUTF(JNIEnv*, const char*);return bbb;
```

需要使用的话还需要定义一个参数，不然 return的返回值 bbb无法从C层回到java层

bbb是个字符串，那么可以使用str，接受后使用`JNI(day)指针类型`指出

![image-20210812214033628](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210812214033628.png)

然后使用`JNIEnv`类型去定义参数，再放入返回值

![image-20210815191518672](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210815191518672.png)

然后再把我们涉及到的两个`.mk`文件搞过来

Android.mk

```Android.mk
LOCAL_PATH := $(call my-dir)include $(CLEAR_VARS)LOCAL_MODULE := JNI_Aaa #模块名称LOCAL_SRC_FILES := JNI_Aaa.c #源文件LOCAL_ARM_MODE := arm #编译后的指令集armLOCAL_LDLIBS += -llog #依赖库include $(BUILD_SHARED_LIBRARY) #指定的编译文件类型
```

注：我们之前要编译的是EXE文件类型 所以使用的是：`include $(BUILD_HARED_LIBRARY)`

今天编译的是so库，所以使用的是：`include $(BUILD_SHARED_LIBRARY)`

Application.mk

```php
APP_ABI := x86 armeabi-v7a
```

![image-20210815160334982](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210815160334982.png)

### 中文乱码问题

![image-20210815160707180](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210815160707180.png)

![image-20210815160645969](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210815160645969.png)

修改为UTF-8即可

![image-20210815160752476](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210815160752476.png)

全部保存后进行编译

### 编译

去jni包所在的目录

进行编译

![image-20210815191635145](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210815191635145.png)

Eclipse进行刷新(F5)

![image-20210815174729793](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210815174729793.png)

`so库`文件在obj目录下

![image-20210815191711492](%E5%AE%89%E5%8D%93%E5%AD%A6%E4%B9%A0(%E5%85%AD).assets/image-20210815191711492.png)

我们的返回值`bbb`在obj的目录下

那么回到java层 把返回值 带回来即可

```php

stati
```

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分类：漏洞分析

安卓学习思路方法总结（五）

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