在Android系统中，JNI方法是以C/C++语言来实现的，然后编译在一个so文件里面，以我之前的例子为例Android Studio使用JNI，调用之前要加载到当前应用程序的进程的地址空间中：
static{ System.loadLibrary("JniTest"); } private native int Add(double num1,double num2); private native int Sub(double num1,double num2); private native int Mul(double num1,double num2); private native int Div(double num1,double num2);
上述方法假设类com.example.caculate有4个方法Add,Sub,Mul,Div是现在libJniTest.so文件中，因此JNI方法被调用之前我们首先要将它加载到当前的应用程序进程中来，通过调用System类的静态成员函数loadLibrary来实现的。
JNI方法的注册我们查看动态注册的代码：
#include <jni.h> #include <stdio.h> //#include <assert.h> #include <stdlib.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> JNIEXPORT jint JNICALL native_Add (JNIEnv *env, jobject obj, jdouble num1, jdouble num2) { return (jint)(num1 + num2 +1); } JNIEXPORT jint JNICALL native_Sub (JNIEnv *env, jobject obj, jdouble num1, jdouble num2) { return (jint)(num1 - num2 +1); } JNIEXPORT jint JNICALL native_Mul (JNIEnv *env, jobject obj, jdouble num1, jdouble num2) { return (jint)(num1 * num2 +1); } JNIEXPORT jint JNICALL native_Div (JNIEnv *env, jobject obj, jdouble num1, jdouble num2) { if (num2 == 0) return 0; return (jint)(num1 / num2 +1); } //Java和JNI函数的绑定表 static JNINativeMethod gMethods[] = { {"Add", "(DD)I", (void *)native_Add}, {"Sub", "(DD)I", (void *)native_Sub}, {"Mul", "(DD)I", (void *)native_Mul}, {"Div", "(DD)I", (void *)native_Div}, }; //注册native方法到java中 static int registerNativeMethods(JNIEnv* env, const char* className, JNINativeMethod* gMethods, int numMethods) { jclass clazz; clazz = (*env)->FindClass(env, className);
if (clazz == NULL) { return JNI_FALSE; } if ((*env)->RegisterNatives(env, clazz, gMethods,numMethods) < 0){ return JNI_FALSE; } return JNI_TRUE; } int register_ndk_load(JNIEnv *env) { return registerNativeMethods(env, "com/example/caculate/MainActivity", gMethods,sizeof(gMethods) / sizeof(gMethods[0])); //NELEM(gMethods)); } JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) { JNIEnv* env = NULL; jint result = -1; if ((*vm)->GetEnv(vm, (void**) &env, JNI_VERSION_1_4) != JNI_OK) { //获得env return result; } register_ndk_load(env); // 返回jni的版本 return JNI_VERSION_1_4; }
经过上述的编码，编译就能生成libJniTest.so文件。
当libJniTest.so文件被加载的时候，函数JNI_OnLoad就会被调用。在函数JNI_Onload中，参数vm是当前进程中的Dalvik虚拟机，通过调用它的成员函数GetEnv就可以获得一个JNIEnv对象。其中JNIEnv是Dalvik虚拟机实例中的一个JNI环境列表，JNIEnv中有个成员变量指向本地接口表JNINativeInterface，当我们在C/C++代码中调用Java函数，就需要用到这个本地接口表，例如调用FindClass找到指定的Java类；调用GetMethodId可以获得一个Java类成员函数，并且可以通过类似CallObjectMethod函数来设置它的值；调用函数RegisterNatives和UnregisterNatives可以注册和反注册JNI方法到一个Java类中，便可以在Java函数中调用；调用GetJavaVM可以获得当前进程中的Dalvik虚拟机实例。每一个关联有JNI环境的线程都有一个对应的JNIEnv对象，JNIEnv是一个双向链表结构，其中第一个是主线程的JNIEnv对象。
之后我们便通过调用JNIEnv对象中接口函数FindClass函数获得当前JNIEnv对象关联的类名
clazz = (*env)->FindClass(env, className);
然后通过JNIEnv对象中接口函数RegisterNatives注册我们的4个方法。
(*env)->RegisterNatives(env, clazz, gMethods,numMethods)
以下分析在Android 4.4源码中
一、我们重点分析JNI的注册过程：
1.我们通过System.loadLibrary()函数加载我们的动态库。我们查看loadLibrary函数。
得到调用过程为
System.loadlibrary() //在System.java中，Java检查是否能被加载，调用Runtime.loadLibrary
|_Runtime.loadLibrary() //在Runtime.java中，检查路径，获得so绝对路径,路径合法，调用Runtime.nativeLoad
|_Runtime.nativeLoad() //JNI方法，Dalvik虚拟机在启动过程中注册的Java核心类操作
|| //在java_lang_Runtime.c中
Dalvik_java_lang_Runtime_nativeLoad()//将java层的String对象转换成C++层字符串，再调用 dvmLoadNativeCode来执行so文件的加载操作
|_dvmLoadNativeCode()
dvmLoadNativeCode()函数检查so文件是否已经加载过了，就直接返回so文件的加载信息，如果没有加载，调用dlopen加载到进程中，创建SharedLib对象pNewEntry来描述加载信息，调用dlsym获得JNI_OnLoad函数在so文件中的函数指针，然后调用这个函数指针，传入JavaVM对象，这个JAVAVM对象描述了当前进程中运行的Dalvik虚拟机。
这样在调用System.loadLibrary()函数，so文件中的JNI_Onload函数就执行了，并且第一个参数描述了当前进程的Dalvik虚拟机对象。
2.JNI_Onload函数注册JNI函数。
(*vm)->GetEnv() //获得Dalvik虚拟机关联的JNIEnv对象(当前线程的JNI环境)
(*env)->FindClass() //JNIEnv结构体中的本地接口表中函数
(*env)->RegisterNatives() //JNIEnv结构体中的本地接口表中函数
||
RegisterNatives()
|_dvmDecodeIndirectRef() //获得要注册JNI方法的类的对象引用clazz
|_dvmRegisterJNIMethod() //通过循环调用此函数，注册methods描述的每一个JNI方法
|_dvmFindDirectMethodByDescriptor //检查method方法是否是clazz的的非虚成员函数
|_dvmFindVirtualMethodByDescriptor //检查method方法是否是clazz的虚成员函数
|_dvmInNativeMethod //确保clazz的成员函数method声明为JNI方法
|_dvmIsSynchronizedMethod //是否是同步的
|_dvmIsStaticMethod //是否是静态方法
|_dvmResolveNativeMethod //检查Dalvik虚拟机内部以及当前所有加载的共享库中是否存在对应的JNI方法
|_dvmUseJNIBridge
|_Bridge=dvmCheckCallJNIMethod / dvmCallJNIMethod //根据虚拟机设置，设置Bridge函数
|_dvmSetNativeFunc 将bridge函数地址和JNI函数地址放入需要注册的JNI的method中
|_method->insns = insns; //JNI方法的函数地址
|_android_atomic_release_store((int32_t) func,
(volatile int32_t*)(void*) &method->nativeFunc); //将dvmCallMethodV函数放入method->nativeFunc中，后面直接通过该函数调用JNI方法的函数地址
参数method表示要注册JNI方法的Java类成员函数，参数func表示JNI方法的Bridge函数（dvmCallJNIMethod或者dvmCheckCallJNIMethod），参数insns表示要注册的JNI方法的函数地址。
当参数insns的值不等于NULL的时候，函数dvmSetNativeFunc就分别将参数insns和func的值分别保存在参数method所指向的一个Method对象的成员变量insns和nativeFunc中，而当insns的值等于NULL的时候，函数dvmSetNativeFunc就只将参数func的值保存在参数method所指向的一个Method对象成员变量nativeFunc中。
到此注册过程已经完成。
二、我们再看看函数的调用过程：
我们通过CallVoidMethodV系列函数调用其他方法，这些函数是JNIEnv结构体中本地接口表中的函数。
CallVoidMethodV
|_dvmCallMethodV (stack.c中)
|_dvmIsNativeMethod() 是JNI方法
| |_(*method->nativeFunc)((u4*)self->interpSave.curFrame, pResult,method, self); //使用之前注册是的bridge函数：dvmCallJNIMethod函数
|_dvmInterpret (Interp.c中) 是Java方法
|_dvmMterpStd JIT和fast模式
|_dvmInterpretPortable Portable可移植模式 (在InterpC-portstd.c中)
|_1.初始化当前要解释的类(methodClassDex)及其成员变量函数(curMethod)、栈帧(fp)、程序计数器(pc)和返回值(retval)，这些值都可以从参数interpState获得。
|_2.再一个无限while循环中，通过FETCH宏依次获得当前程序计数器(pc)的指令，并通过宏INST_INST获得指令inst的类型，最后就switch到对应的分支去解释指令inst。
其中dvmCheckCallJNIMethod检查JNI之后调用dvmCallJNIMethod函数(jni.c中)
调用之前注册JNI时指定的dvmCallJNIMethod函数，通过这个函数执行JNI方法
dvmCallJNIMethod
|_addLocalReference(thread,method->clazz) 增加线程对java类对象的引用
|_dvmChangeStatus(thread,THREAD_NATIVE) 更改线程状态为native模式
|_dvmPlatformInvoke() //函数通过libffi库来调用对应的JNI方法，来屏蔽Dalvik虚拟机运行在不同目标平台的细节
|_dvmChangeStatus() 恢复线程状态
JNI环境对象结构体：
struct JNIEnvExt { //JNI环境对象 const struct JNINativeInterface* funcTable; /* must be first */ const struct JNINativeInterface* baseFuncTable; u4 envThreadId; Thread* self; /* if nonzero, we are in a "critical" JNI call */ int critical; struct JNIEnvExt* prev; struct JNIEnvExt* next; };
JNINativeInterface： JNIEnv的回调函数表
1 struct JNINativeInterface { 2 void* reserved0; 3 void* reserved1; 4 void* reserved2; 5 void* reserved3; 6 7 jint (*GetVersion)(JNIEnv *); 8 9 jclass (*DefineClass)(JNIEnv*, const char*, jobject, const jbyte*, 10 jsize); 11 jclass (*FindClass)(JNIEnv*, const char*); 12 13 jmethodID (*FromReflectedMethod)(JNIEnv*, jobject); 14 jfieldID (*FromReflectedField)(JNIEnv*, jobject); 15 /* spec doesn't show jboolean parameter */ 16 jobject (*ToReflectedMethod)(JNIEnv*, jclass, jmethodID, jboolean); 17 18 jclass (*GetSuperclass)(JNIEnv*, jclass); 19 jboolean (*IsAssignableFrom)(JNIEnv*, jclass, jclass); 20 21 /* spec doesn't show jboolean parameter */ 22 jobject (*ToReflectedField)(JNIEnv*, jclass, jfieldID, jboolean); 23 24 jint (*Throw)(JNIEnv*, jthrowable); 25 jint (*ThrowNew)(JNIEnv *, jclass, const char *); 26 jthrowable (*ExceptionOccurred)(JNIEnv*); 27 void (*ExceptionDescribe)(JNIEnv*); 28 void (*ExceptionClear)(JNIEnv*); 29 void (*FatalError)(JNIEnv*, const char*); 30 31 jint (*PushLocalFrame)(JNIEnv*, jint); 32 jobject (*PopLocalFrame)(JNIEnv*, jobject); 33 34 jobject (*NewGlobalRef)(JNIEnv*, jobject); 35 void (*DeleteGlobalRef)(JNIEnv*, jobject); 36 void (*DeleteLocalRef)(JNIEnv*, jobject); 37 jboolean (*IsSameObject)(JNIEnv*, jobject, jobject); 38 39 jobject (*NewLocalRef)(JNIEnv*, jobject); 40 jint (*EnsureLocalCapacity)(JNIEnv*, jint); 41 42 jobject (*AllocObject)(JNIEnv*, jclass); 43 jobject (*NewObject)(JNIEnv*, jclass, jmethodID, ...); 44 jobject (*NewObjectV)(JNIEnv*, jclass, jmethodID, va_list); 45 jobject (*NewObjectA)(JNIEnv*, jclass, jmethodID, jvalue*); 46 47 jclass (*GetObjectClass)(JNIEnv*, jobject); 48 jboolean (*IsInstanceOf)(JNIEnv*, jobject, jclass); 49 jmethodID (*GetMethodID)(JNIEnv*, jclass, const char*, const char*); 50 51 jobject (*CallObjectMethod)(JNIEnv*, jobject, jmethodID, ...); 52 jobject (*CallObjectMethodV)(JNIEnv*, jobject, jmethodID, va_list); 53 jobject (*CallObjectMethodA)(JNIEnv*, jobject, jmethodID, jvalue*); 54 jboolean (*CallBooleanMethod)(JNIEnv*, jobject, jmethodID, ...); 55 jboolean (*CallBooleanMethodV)(JNIEnv*, jobject, jmethodID, va_list); 56 jboolean (*CallBooleanMethodA)(JNIEnv*, jobject, jmethodID, jvalue*); 57 jbyte (*CallByteMethod)(JNIEnv*, jobject, jmethodID, ...); 58 jbyte (*CallByteMethodV)(JNIEnv*, jobject, jmethodID, va_list); 59 jbyte (*CallByteMethodA)(JNIEnv*, jobject, jmethodID, jvalue*); 60 jchar (*CallCharMethod)(JNIEnv*, jobject, jmethodID, ...); 61 jchar (*CallCharMethodV)(JNIEnv*, jobject, jmethodID, va_list); 62 jchar (*CallCharMethodA)(JNIEnv*, jobject, jmethodID, jvalue*); 63 jshort (*CallShortMethod)(JNIEnv*, jobject, jmethodID, ...); 64 jshort (*CallShortMethodV)(JNIEnv*, jobject, jmethodID, va_list); 65 jshort (*CallShortMethodA)(JNIEnv*, jobject, jmethodID, jvalue*); 66 jint (*CallIntMethod)(JNIEnv*, jobject, jmethodID, ...); 67 jint (*CallIntMethodV)(JNIEnv*, jobject, jmethodID, va_list); 68 jint (*CallIntMethodA)(JNIEnv*, jobject, jmethodID, jvalue*); 69 jlong (*CallLongMethod)(JNIEnv*, jobject, jmethodID, ...); 70 jlong (*CallLongMethodV)(JNIEnv*, jobject, jmethodID, va_list); 71 jlong (*CallLongMethodA)(JNIEnv*, jobject, jmethodID, jvalue*); 72 jfloat (*CallFloatMethod)(JNIEnv*, jobject, jmethodID, ...); 73 jfloat (*CallFloatMethodV)(JNIEnv*, jobject, jmethodID, va_list); 74 jfloat (*CallFloatMethodA)(JNIEnv*, jobject, jmethodID, jvalue*); 75 jdouble (*CallDoubleMethod)(JNIEnv*, jobject, jmethodID, ...); 76 jdouble (*CallDoubleMethodV)(JNIEnv*, jobject, jmethodID, va_list); 77 jdouble (*CallDoubleMethodA)(JNIEnv*, jobject, jmethodID, jvalue*); 78 void (*CallVoidMethod)(JNIEnv*, jobject, jmethodID, ...); 79 void (*CallVoidMethodV)(JNIEnv*, jobject, jmethodID, va_list); 80 void (*CallVoidMethodA)(JNIEnv*, jobject, jmethodID, jvalue*); 81 82 jobject (*CallNonvirtualObjectMethod)(JNIEnv*, jobject, jclass, 83 jmethodID, ...); 84 jobject (*CallNonvirtualObjectMethodV)(JNIEnv*, jobject, jclass, 85 jmethodID, va_list); 86 jobject (*CallNonvirtualObjectMethodA)(JNIEnv*, jobject, jclass, 87 jmethodID, jvalue*); 88 jboolean (*CallNonvirtualBooleanMethod)(JNIEnv*, jobject, jclass, 89 jmethodID, ...); 90 jboolean (*CallNonvirtualBooleanMethodV)(JNIEnv*, jobject, jclass, 91 jmethodID, va_list); 92 jboolean (*CallNonvirtualBooleanMethodA)(JNIEnv*, jobject, jclass, 93 jmethodID, jvalue*); 94 jbyte (*CallNonvirtualByteMethod)(JNIEnv*, jobject, jclass, 95 jmethodID, ...); 96 jbyte (*CallNonvirtualByteMethodV)(JNIEnv*, jobject, jclass, 97 jmethodID, va_list); 98 jbyte (*CallNonvirtualByteMethodA)(JNIEnv*, jobject, jclass, 99 jmethodID, jvalue*); 100 jchar (*CallNonvirtualCharMethod)(JNIEnv*, jobject, jclass, 101 jmethodID, ...); 102 jchar (*CallNonvirtualCharMethodV)(JNIEnv*, jobject, jclass, 103 jmethodID, va_list); 104 jchar (*CallNonvirtualCharMethodA)(JNIEnv*, jobject, jclass, 105 jmethodID, jvalue*); 106 jshort (*CallNonvirtualShortMethod)(JNIEnv*, jobject, jclass, 107 jmethodID, ...); 108 jshort (*CallNonvirtualShortMethodV)(JNIEnv*, jobject, jclass, 109 jmethodID, va_list); 110 jshort (*CallNonvirtualShortMethodA)(JNIEnv*, jobject, jclass, 111 jmethodID, jvalue*); 112 jint (*CallNonvirtualIntMethod)(JNIEnv*, jobject, jclass, 113 jmethodID, ...); 114 jint (*CallNonvirtualIntMethodV)(JNIEnv*, jobject, jclass, 115 jmethodID, va_list); 116 jint (*CallNonvirtualIntMethodA)(JNIEnv*, jobject, jclass, 117 jmethodID, jvalue*); 118 jlong (*CallNonvirtualLongMethod)(JNIEnv*, jobject, jclass, 119 jmethodID, ...); 120 jlong (*CallNonvirtualLongMethodV)(JNIEnv*, jobject, jclass, 121 jmethodID, va_list); 122 jlong (*CallNonvirtualLongMethodA)(JNIEnv*, jobject, jclass, 123 jmethodID, jvalue*); 124 jfloat (*CallNonvirtualFloatMethod)(JNIEnv*, jobject, jclass, 125 jmethodID, ...); 126 jfloat (*CallNonvirtualFloatMethodV)(JNIEnv*, jobject, jclass, 127 jmethodID, va_list); 128 jfloat (*CallNonvirtualFloatMethodA)(JNIEnv*, jobject, jclass, 129 jmethodID, jvalue*); 130 jdouble (*CallNonvirtualDoubleMethod)(JNIEnv*, jobject, jclass, 131 jmethodID, ...); 132 jdouble (*CallNonvirtualDoubleMethodV)(JNIEnv*, jobject, jclass, 133 jmethodID, va_list); 134 jdouble (*CallNonvirtualDoubleMethodA)(JNIEnv*, jobject, jclass, 135 jmethodID, jvalue*); 136 void (*CallNonvirtualVoidMethod)(JNIEnv*, jobject, jclass, 137 jmethodID, ...); 138 void (*CallNonvirtualVoidMethodV)(JNIEnv*, jobject, jclass, 139 jmethodID, va_list); 140 void (*CallNonvirtualVoidMethodA)(JNIEnv*, jobject, jclass, 141 jmethodID, jvalue*); 142 143 jfieldID (*GetFieldID)(JNIEnv*, jclass, const char*, const char*); 144 145 jobject (*GetObjectField)(JNIEnv*, jobject, jfieldID); 146 jboolean (*GetBooleanField)(JNIEnv*, jobject, jfieldID); 147 jbyte (*GetByteField)(JNIEnv*, jobject, jfieldID); 148 jchar (*GetCharField)(JNIEnv*, jobject, jfieldID); 149 jshort (*GetShortField)(JNIEnv*, jobject, jfieldID); 150 jint (*GetIntField)(JNIEnv*, jobject, jfieldID); 151 jlong (*GetLongField)(JNIEnv*, jobject, jfieldID); 152 jfloat (*GetFloatField)(JNIEnv*, jobject, jfieldID); 153 jdouble (*GetDoubleField)(JNIEnv*, jobject, jfieldID); 154 155 void (*SetObjectField)(JNIEnv*, jobject, jfieldID, jobject); 156 void (*SetBooleanField)(JNIEnv*, jobject, jfieldID, jboolean); 157 void (*SetByteField)(JNIEnv*, jobject, jfieldID, jbyte); 158 void (*SetCharField)(JNIEnv*, jobject, jfieldID, jchar); 159 void (*SetShortField)(JNIEnv*, jobject, jfieldID, jshort); 160 void (*SetIntField)(JNIEnv*, jobject, jfieldID, jint); 161 void (*SetLongField)(JNIEnv*, jobject, jfieldID, jlong); 162 void (*SetFloatField)(JNIEnv*, jobject, jfieldID, jfloat); 163 void (*SetDoubleField)(JNIEnv*, jobject, jfieldID, jdouble); 164 165 jmethodID (*GetStaticMethodID)(JNIEnv*, jclass, const char*, const char*); 166 167 jobject (*CallStaticObjectMethod)(JNIEnv*, jclass, jmethodID, ...); 168 jobject (*CallStaticObjectMethodV)(JNIEnv*, jclass, jmethodID, va_list); 169 jobject (*CallStaticObjectMethodA)(JNIEnv*, jclass, jmethodID, jvalue*); 170 jboolean (*CallStaticBooleanMethod)(JNIEnv*, jclass, jmethodID, ...); 171 jboolean (*CallStaticBooleanMethodV)(JNIEnv*, jclass, jmethodID, 172 va_list); 173 jboolean (*CallStaticBooleanMethodA)(JNIEnv*, jclass, jmethodID, 174 jvalue*); 175 jbyte (*CallStaticByteMethod)(JNIEnv*, jclass, jmethodID, ...); 176 jbyte (*CallStaticByteMethodV)(JNIEnv*, jclass, jmethodID, va_list); 177 jbyte (*CallStaticByteMethodA)(JNIEnv*, jclass, jmethodID, jvalue*); 178 jchar (*CallStaticCharMethod)(JNIEnv*, jclass, jmethodID, ...); 179 jchar (*CallStaticCharMethodV)(JNIEnv*, jclass, jmethodID, va_list); 180 jchar (*CallStaticCharMethodA)(JNIEnv*, jclass, jmethodID, jvalue*); 181 jshort (*CallStaticShortMethod)(JNIEnv*, jclass, jmethodID, ...); 182 jshort (*CallStaticShortMethodV)(JNIEnv*, jclass, jmethodID, va_list); 183 jshort (*CallStaticShortMethodA)(JNIEnv*, jclass, jmethodID, jvalue*); 184 jint (*CallStaticIntMethod)(JNIEnv*, jclass, jmethodID, ...); 185 jint (*CallStaticIntMethodV)(JNIEnv*, jclass, jmethodID, va_list); 186 jint (*CallStaticIntMethodA)(JNIEnv*, jclass, jmethodID, jvalue*); 187 jlong (*CallStaticLongMethod)(JNIEnv*, jclass, jmethodID, ...); 188 jlong (*CallStaticLongMethodV)(JNIEnv*, jclass, jmethodID, va_list); 189 jlong (*CallStaticLongMethodA)(JNIEnv*, jclass, jmethodID, jvalue*); 190 jfloat (*CallStaticFloatMethod)(JNIEnv*, jclass, jmethodID, ...); 191 jfloat (*CallStaticFloatMethodV)(JNIEnv*, jclass, jmethodID, va_list); 192 jfloat (*CallStaticFloatMethodA)(JNIEnv*, jclass, jmethodID, jvalue*); 193 jdouble (*CallStaticDoubleMethod)(JNIEnv*, jclass, jmethodID, ...); 194 jdouble (*CallStaticDoubleMethodV)(JNIEnv*, jclass, jmethodID, va_list); 195 jdouble (*CallStaticDoubleMethodA)(JNIEnv*, jclass, jmethodID, jvalue*); 196 void (*CallStaticVoidMethod)(JNIEnv*, jclass, jmethodID, ...); 197 void (*CallStaticVoidMethodV)(JNIEnv*, jclass, jmethodID, va_list); 198 void (*CallStaticVoidMethodA)(JNIEnv*, jclass, jmethodID, jvalue*); 199 200 jfieldID (*GetStaticFieldID)(JNIEnv*, jclass, const char*, 201 const char*); 202 203 jobject (*GetStaticObjectField)(JNIEnv*, jclass, jfieldID); 204 jboolean (*GetStaticBooleanField)(JNIEnv*, jclass, jfieldID); 205 jbyte (*GetStaticByteField)(JNIEnv*, jclass, jfieldID); 206 jchar (*GetStaticCharField)(JNIEnv*, jclass, jfieldID); 207 jshort (*GetStaticShortField)(JNIEnv*, jclass, jfieldID); 208 jint (*GetStaticIntField)(JNIEnv*, jclass, jfieldID); 209 jlong (*GetStaticLongField)(JNIEnv*, jclass, jfieldID); 210 jfloat (*GetStaticFloatField)(JNIEnv*, jclass, jfieldID); 211 jdouble (*GetStaticDoubleField)(JNIEnv*, jclass, jfieldID); 212 213 void (*SetStaticObjectField)(JNIEnv*, jclass, jfieldID, jobject); 214 void (*SetStaticBooleanField)(JNIEnv*, jclass, jfieldID, jboolean); 215 void (*SetStaticByteField)(JNIEnv*, jclass, jfieldID, jbyte); 216 void (*SetStaticCharField)(JNIEnv*, jclass, jfieldID, jchar); 217 void (*SetStaticShortField)(JNIEnv*, jclass, jfieldID, jshort); 218 void (*SetStaticIntField)(JNIEnv*, jclass, jfieldID, jint); 219 void (*SetStaticLongField)(JNIEnv*, jclass, jfieldID, jlong); 220 void (*SetStaticFloatField)(JNIEnv*, jclass, jfieldID, jfloat); 221 void (*SetStaticDoubleField)(JNIEnv*, jclass, jfieldID, jdouble); 222 223 jstring (*NewString)(JNIEnv*, const jchar*, jsize); 224 jsize (*GetStringLength)(JNIEnv*, jstring); 225 const jchar* (*GetStringChars)(JNIEnv*, jstring, jboolean*); 226 void (*ReleaseStringChars)(JNIEnv*, jstring, const jchar*); 227 jstring (*NewStringUTF)(JNIEnv*, const char*); 228 jsize (*GetStringUTFLength)(JNIEnv*, jstring); 229 /* JNI spec says this returns const jbyte*, but that's inconsistent */ 230 const char* (*GetStringUTFChars)(JNIEnv*, jstring, jboolean*); 231 void (*ReleaseStringUTFChars)(JNIEnv*, jstring, const char*); 232 jsize (*GetArrayLength)(JNIEnv*, jarray); 233 jobjectArray (*NewObjectArray)(JNIEnv*, jsize, jclass, jobject); 234 jobject (*GetObjectArrayElement)(JNIEnv*, jobjectArray, jsize); 235 void (*SetObjectArrayElement)(JNIEnv*, jobjectArray, jsize, jobject); 236 237 jbooleanArray (*NewBooleanArray)(JNIEnv*, jsize); 238 jbyteArray (*NewByteArray)(JNIEnv*, jsize); 239 jcharArray (*NewCharArray)(JNIEnv*, jsize); 240 jshortArray (*NewShortArray)(JNIEnv*, jsize); 241 jintArray (*NewIntArray)(JNIEnv*, jsize); 242 jlongArray (*NewLongArray)(JNIEnv*, jsize); 243 jfloatArray (*NewFloatArray)(JNIEnv*, jsize); 244 jdoubleArray (*NewDoubleArray)(JNIEnv*, jsize); 245 246 jboolean* (*GetBooleanArrayElements)(JNIEnv*, jbooleanArray, jboolean*); 247 jbyte* (*GetByteArrayElements)(JNIEnv*, jbyteArray, jboolean*); 248 jchar* (*GetCharArrayElements)(JNIEnv*, jcharArray, jboolean*); 249 jshort* (*GetShortArrayElements)(JNIEnv*, jshortArray, jboolean*); 250 jint* (*GetIntArrayElements)(JNIEnv*, jintArray, jboolean*); 251 jlong* (*GetLongArrayElements)(JNIEnv*, jlongArray, jboolean*); 252 jfloat* (*GetFloatArrayElements)(JNIEnv*, jfloatArray, jboolean*); 253 jdouble* (*GetDoubleArrayElements)(JNIEnv*, jdoubleArray, jboolean*); 254 255 void (*ReleaseBooleanArrayElements)(JNIEnv*, jbooleanArray, 256 jboolean*, jint); 257 void (*ReleaseByteArrayElements)(JNIEnv*, jbyteArray, 258 jbyte*, jint); 259 void (*ReleaseCharArrayElements)(JNIEnv*, jcharArray, 260 jchar*, jint); 261 void (*ReleaseShortArrayElements)(JNIEnv*, jshortArray, 262 jshort*, jint); 263 void (*ReleaseIntArrayElements)(JNIEnv*, jintArray, 264 jint*, jint); 265 void (*ReleaseLongArrayElements)(JNIEnv*, jlongArray, 266 jlong*, jint); 267 void (*ReleaseFloatArrayElements)(JNIEnv*, jfloatArray, 268 jfloat*, jint); 269 void (*ReleaseDoubleArrayElements)(JNIEnv*, jdoubleArray, 270 jdouble*, jint); 271 272 void (*GetBooleanArrayRegion)(JNIEnv*, jbooleanArray, 273 jsize, jsize, jboolean*); 274 void (*GetByteArrayRegion)(JNIEnv*, jbyteArray, 275 jsize, jsize, jbyte*); 276 void (*GetCharArrayRegion)(JNIEnv*, jcharArray, 277 jsize, jsize, jchar*); 278 void (*GetShortArrayRegion)(JNIEnv*, jshortArray, 279 jsize, jsize, jshort*); 280 void (*GetIntArrayRegion)(JNIEnv*, jintArray, 281 jsize, jsize, jint*); 282 void (*GetLongArrayRegion)(JNIEnv*, jlongArray, 283 jsize, jsize, jlong*); 284 void (*GetFloatArrayRegion)(JNIEnv*, jfloatArray, 285 jsize, jsize, jfloat*); 286 void (*GetDoubleArrayRegion)(JNIEnv*, jdoubleArray, 287 jsize, jsize, jdouble*); 288 289 /* spec shows these without const; some jni.h do, some don't */ 290 void (*SetBooleanArrayRegion)(JNIEnv*, jbooleanArray, 291 jsize, jsize, const jboolean*); 292 void (*SetByteArrayRegion)(JNIEnv*, jbyteArray, 293 jsize, jsize, const jbyte*); 294 void (*SetCharArrayRegion)(JNIEnv*, jcharArray, 295 jsize, jsize, const jchar*); 296 void (*SetShortArrayRegion)(JNIEnv*, jshortArray, 297 jsize, jsize, const jshort*); 298 void (*SetIntArrayRegion)(JNIEnv*, jintArray, 299 jsize, jsize, const jint*); 300 void (*SetLongArrayRegion)(JNIEnv*, jlongArray, 301 jsize, jsize, const jlong*); 302 void (*SetFloatArrayRegion)(JNIEnv*, jfloatArray, 303 jsize, jsize, const jfloat*); 304 void (*SetDoubleArrayRegion)(JNIEnv*, jdoubleArray, 305 jsize, jsize, const jdouble*); 306 307 jint (*RegisterNatives)(JNIEnv*, jclass, const JNINativeMethod*, 308 jint); 309 jint (*UnregisterNatives)(JNIEnv*, jclass); 310 jint (*MonitorEnter)(JNIEnv*, jobject); 311 jint (*MonitorExit)(JNIEnv*, jobject); 312 jint (*GetJavaVM)(JNIEnv*, JavaVM**); 313 314 void (*GetStringRegion)(JNIEnv*, jstring, jsize, jsize, jchar*); 315 void (*GetStringUTFRegion)(JNIEnv*, jstring, jsize, jsize, char*); 316 317 void* (*GetPrimitiveArrayCritical)(JNIEnv*, jarray, jboolean*); 318 void (*ReleasePrimitiveArrayCritical)(JNIEnv*, jarray, void*, jint); 319 320 const jchar* (*GetStringCritical)(JNIEnv*, jstring, jboolean*); 321 void (*ReleaseStringCritical)(JNIEnv*, jstring, const jchar*); 322 323 jweak (*NewWeakGlobalRef)(JNIEnv*, jobject); 324 void (*DeleteWeakGlobalRef)(JNIEnv*, jweak); 325 326 jboolean (*ExceptionCheck)(JNIEnv*); 327 328 jobject (*NewDirectByteBuffer)(JNIEnv*, void*, jlong); 329 void* (*GetDirectBufferAddress)(JNIEnv*, jobject); 330 jlong (*GetDirectBufferCapacity)(JNIEnv*, jobject); 331 332 /* added in JNI 1.6 */ 333 jobjectRefType (*GetObjectRefType)(JNIEnv*, jobject); 334 }; 335 336 /* 337 * C++ object wrapper. 338 * 339 * This is usually overlaid on a C struct whose first element is a 340 * JNINativeInterface*. We rely somewhat on compiler behavior. 341 */ 342 struct _JNIEnv { 343 /* do not rename this; it does not seem to be entirely opaque */ 344 const struct JNINativeInterface* functions; 345 346 #if defined(__cplusplus) 347 348 jint GetVersion() 349 { return functions->GetVersion(this); } 350 351 jclass DefineClass(const char *name, jobject loader, const jbyte* buf, 352 jsize bufLen) 353 { return functions->DefineClass(this, name, loader, buf, bufLen); } 354 355 jclass FindClass(const char* name) 356 { return functions->FindClass(this, name); } 357 358 jmethodID FromReflectedMethod(jobject method) 359 { return functions->FromReflectedMethod(this, method); } 360 361 jfieldID FromReflectedField(jobject field) 362 { return functions->FromReflectedField(this, field); } 363 364 jobject ToReflectedMethod(jclass cls, jmethodID methodID, jboolean isStatic) 365 { return functions->ToReflectedMethod(this, cls, methodID, isStatic); } 366 367 jclass GetSuperclass(jclass clazz) 368 { return functions->GetSuperclass(this, clazz); } 369 370 jboolean IsAssignableFrom(jclass clazz1, jclass clazz2) 371 { return functions->IsAssignableFrom(this, clazz1, clazz2); } 372 373 jobject ToReflectedField(jclass cls, jfieldID fieldID, jboolean isStatic) 374 { return functions->ToReflectedField(this, cls, fieldID, isStatic); } 375 376 jint Throw(jthrowable obj) 377 { return functions->Throw(this, obj); } 378 379 jint ThrowNew(jclass clazz, const char* message) 380 { return functions->ThrowNew(this, clazz, message); } 381 382 jthrowable ExceptionOccurred() 383 { return functions->ExceptionOccurred(this); } 384 385 void ExceptionDescribe() 386 { functions->ExceptionDescribe(this); } 387 388 void ExceptionClear() 389 { functions->ExceptionClear(this); } 390 391 void FatalError(const char* msg) 392 { functions->FatalError(this, msg); } 393 394 jint PushLocalFrame(jint capacity) 395 { return functions->PushLocalFrame(this, capacity); } 396 397 jobject PopLocalFrame(jobject result) 398 { return functions->PopLocalFrame(this, result); } 399 400 jobject NewGlobalRef(jobject obj) 401 { return functions->NewGlobalRef(this, obj); } 402 403 void DeleteGlobalRef(jobject globalRef) 404 { functions->DeleteGlobalRef(this, globalRef); } 405 406 void DeleteLocalRef(jobject localRef) 407 { functions->DeleteLocalRef(this, localRef); } 408 409 jboolean IsSameObject(jobject ref1, jobject ref2) 410 { return functions->IsSameObject(this, ref1, ref2); } 411 412 jobject NewLocalRef(jobject ref) 413 { return functions->NewLocalRef(this, ref); } 414 415 jint EnsureLocalCapacity(jint capacity) 416 { return functions->EnsureLocalCapacity(this, capacity); } 417 418 jobject AllocObject(jclass clazz) 419 { return functions->AllocObject(this, clazz); } 420 421 jobject NewObject(jclass clazz, jmethodID methodID, ...) 422 { 423 va_list args; 424 va_start(args, methodID); 425 jobject result = functions->NewObjectV(this, clazz, methodID, args); 426 va_end(args); 427 return result; 428 } 429 430 jobject NewObjectV(jclass clazz, jmethodID methodID, va_list args) 431 { return functions->NewObjectV(this, clazz, methodID, args); } 432 433 jobject NewObjectA(jclass clazz, jmethodID methodID, jvalue* args) 434 { return functions->NewObjectA(this, clazz, methodID, args); } 435 436 jclass GetObjectClass(jobject obj) 437 { return functions->GetObjectClass(this, obj); } 438 439 jboolean IsInstanceOf(jobject obj, jclass clazz) 440 { return functions->IsInstanceOf(this, obj, clazz); } 441 442 jmethodID GetMethodID(jclass clazz, const char* name, const char* sig) 443 { return functions->GetMethodID(this, clazz, name, sig); } 444 445 #define CALL_TYPE_METHOD(_jtype, _jname) 446 _jtype Call##_jname##Method(jobject obj, jmethodID methodID, ...) 447 { 448 _jtype result; 449 va_list args; 450 va_start(args, methodID); 451 result = functions->Call##_jname##MethodV(this, obj, methodID, 452 args); 453 va_end(args); 454 return result; 455 } 456 #define CALL_TYPE_METHODV(_jtype, _jname) 457 _jtype Call##_jname##MethodV(jobject obj, jmethodID methodID, 458 va_list args) 459 { return functions->Call##_jname##MethodV(this, obj, methodID, args); } 460 #define CALL_TYPE_METHODA(_jtype, _jname) 461 _jtype Call##_jname##MethodA(jobject obj, jmethodID methodID, 462 jvalue* args) 463 { return functions->Call##_jname##MethodA(this, obj, methodID, args); } 464 465 #define CALL_TYPE(_jtype, _jname) 466 CALL_TYPE_METHOD(_jtype, _jname) 467 CALL_TYPE_METHODV(_jtype, _jname) 468 CALL_TYPE_METHODA(_jtype, _jname) 469 470 CALL_TYPE(jobject, Object) 471 CALL_TYPE(jboolean, Boolean) 472 CALL_TYPE(jbyte, Byte) 473 CALL_TYPE(jchar, Char) 474 CALL_TYPE(jshort, Short) 475 CALL_TYPE(jint, Int) 476 CALL_TYPE(jlong, Long) 477 CALL_TYPE(jfloat, Float) 478 CALL_TYPE(jdouble, Double) 479 480 void CallVoidMethod(jobject obj, jmethodID methodID, ...) 481 { 482 va_list args; 483 va_start(args, methodID); 484 functions->CallVoidMethodV(this, obj, methodID, args); 485 va_end(args); 486 } 487 void CallVoidMethodV(jobject obj, jmethodID methodID, va_list args) 488 { functions->CallVoidMethodV(this, obj, methodID, args); } 489 void CallVoidMethodA(jobject obj, jmethodID methodID, jvalue* args) 490 { functions->CallVoidMethodA(this, obj, methodID, args); } 491 492 #define CALL_NONVIRT_TYPE_METHOD(_jtype, _jname) 493 _jtype CallNonvirtual##_jname##Method(jobject obj, jclass clazz, 494 jmethodID methodID, ...) 495 { 496 _jtype result; 497 va_list args; 498 va_start(args, methodID); 499 result = functions->CallNonvirtual##_jname##MethodV(this, obj, 500 clazz, methodID, args); 501 va_end(args); 502 return result; 503 } 504 #define CALL_NONVIRT_TYPE_METHODV(_jtype, _jname) 505 _jtype CallNonvirtual##_jname##MethodV(jobject obj, jclass clazz, 506 jmethodID methodID, va_list args) 507 { return functions->CallNonvirtual##_jname##MethodV(this, obj, clazz, 508 methodID, args); } 509 #define CALL_NONVIRT_TYPE_METHODA(_jtype, _jname) 510 _jtype CallNonvirtual##_jname##MethodA(jobject obj, jclass clazz, 511 jmethodID methodID, jvalue* args) 512 { return functions->CallNonvirtual##_jname##MethodA(this, obj, clazz, 513 methodID, args); } 514 515 #define CALL_NONVIRT_TYPE(_jtype, _jname) 516 CALL_NONVIRT_TYPE_METHOD(_jtype, _jname) 517 CALL_NONVIRT_TYPE_METHODV(_jtype, _jname) 518 CALL_NONVIRT_TYPE_METHODA(_jtype, _jname) 519 520 CALL_NONVIRT_TYPE(jobject, Object) 521 CALL_NONVIRT_TYPE(jboolean, Boolean) 522 CALL_NONVIRT_TYPE(jbyte, Byte) 523 CALL_NONVIRT_TYPE(jchar, Char) 524 CALL_NONVIRT_TYPE(jshort, Short) 525 CALL_NONVIRT_TYPE(jint, Int) 526 CALL_NONVIRT_TYPE(jlong, Long) 527 CALL_NONVIRT_TYPE(jfloat, Float) 528 CALL_NONVIRT_TYPE(jdouble, Double) 529 530 void CallNonvirtualVoidMethod(jobject obj, jclass clazz, 531 jmethodID methodID, ...) 532 { 533 va_list args; 534 va_start(args, methodID); 535 functions->CallNonvirtualVoidMethodV(this, obj, clazz, methodID, args); 536 va_end(args); 537 } 538 void CallNonvirtualVoidMethodV(jobject obj, jclass clazz, 539 jmethodID methodID, va_list args) 540 { functions->CallNonvirtualVoidMethodV(this, obj, clazz, methodID, args); } 541 void CallNonvirtualVoidMethodA(jobject obj, jclass clazz, 542 jmethodID methodID, jvalue* args) 543 { functions->CallNonvirtualVoidMethodA(this, obj, clazz, methodID, args); } 544 545 jfieldID GetFieldID(jclass clazz, const char* name, const char* sig) 546 { return functions->GetFieldID(this, clazz, name, sig); } 547 548 jobject GetObjectField(jobject obj, jfieldID fieldID) 549 { return functions->GetObjectField(this, obj, fieldID); } 550 jboolean GetBooleanField(jobject obj, jfieldID fieldID) 551 { return functions->GetBooleanField(this, obj, fieldID); } 552 jbyte GetByteField(jobject obj, jfieldID fieldID) 553 { return functions->GetByteField(this, obj, fieldID); } 554 jchar GetCharField(jobject obj, jfieldID fieldID) 555 { return functions->GetCharField(this, obj, fieldID); } 556 jshort GetShortField(jobject obj, jfieldID fieldID) 557 { return functions->GetShortField(this, obj, fieldID); } 558 jint GetIntField(jobject obj, jfieldID fieldID) 559 { return functions->GetIntField(this, obj, fieldID); } 560 jlong GetLongField(jobject obj, jfieldID fieldID) 561 { return functions->GetLongField(this, obj, fieldID); } 562 jfloat GetFloatField(jobject obj, jfieldID fieldID) 563 { return functions->GetFloatField(this, obj, fieldID); } 564 jdouble GetDoubleField(jobject obj, jfieldID fieldID) 565 { return functions->GetDoubleField(this, obj, fieldID); } 566 567 void SetObjectField(jobject obj, jfieldID fieldID, jobject value) 568 { functions->SetObjectField(this, obj, fieldID, value); } 569 void SetBooleanField(jobject obj, jfieldID fieldID, jboolean value) 570 { functions->SetBooleanField(this, obj, fieldID, value); } 571 void SetByteField(jobject obj, jfieldID fieldID, jbyte value) 572 { functions->SetByteField(this, obj, fieldID, value); } 573 void SetCharField(jobject obj, jfieldID fieldID, jchar value) 574 { functions->SetCharField(this, obj, fieldID, value); } 575 void SetShortField(jobject obj, jfieldID fieldID, jshort value) 576 { functions->SetShortField(this, obj, fieldID, value); } 577 void SetIntField(jobject obj, jfieldID fieldID, jint value) 578 { functions->SetIntField(this, obj, fieldID, value); } 579 void SetLongField(jobject obj, jfieldID fieldID, jlong value) 580 { functions->SetLongField(this, obj, fieldID, value); } 581 void SetFloatField(jobject obj, jfieldID fieldID, jfloat value) 582 { functions->SetFloatField(this, obj, fieldID, value); } 583 void SetDoubleField(jobject obj, jfieldID fieldID, jdouble value) 584 { functions->SetDoubleField(this, obj, fieldID, value); } 585 586 jmethodID GetStaticMethodID(jclass clazz, const char* name, const char* sig) 587 { return functions->GetStaticMethodID(this, clazz, name, sig); } 588 589 #define CALL_STATIC_TYPE_METHOD(_jtype, _jname) 590 _jtype CallStatic##_jname##Method(jclass clazz, jmethodID methodID, 591 ...) 592 { 593 _jtype result; 594 va_list args; 595 va_start(args, methodID); 596 result = functions->CallStatic##_jname##MethodV(this, clazz, 597 methodID, args); 598 va_end(args); 599 return result; 600 } 601 #define CALL_STATIC_TYPE_METHODV(_jtype, _jname) 602 _jtype CallStatic##_jname##MethodV(jclass clazz, jmethodID methodID, 603 va_list args) 604 { return functions->CallStatic##_jname##MethodV(this, clazz, methodID, 605 args); } 606 #define CALL_STATIC_TYPE_METHODA(_jtype, _jname) 607 _jtype CallStatic##_jname##MethodA(jclass clazz, jmethodID methodID, 608 jvalue* args) 609 { return functions->CallStatic##_jname##MethodA(this, clazz, methodID, 610 args); } 611 612 #define CALL_STATIC_TYPE(_jtype, _jname) 613 CALL_STATIC_TYPE_METHOD(_jtype, _jname) 614 CALL_STATIC_TYPE_METHODV(_jtype, _jname) 615 CALL_STATIC_TYPE_METHODA(_jtype, _jname) 616 617 CALL_STATIC_TYPE(jobject, Object) 618 CALL_STATIC_TYPE(jboolean, Boolean) 619 CALL_STATIC_TYPE(jbyte, Byte) 620 CALL_STATIC_TYPE(jchar, Char) 621 CALL_STATIC_TYPE(jshort, Short) 622 CALL_STATIC_TYPE(jint, Int) 623 CALL_STATIC_TYPE(jlong, Long) 624 CALL_STATIC_TYPE(jfloat, Float) 625 CALL_STATIC_TYPE(jdouble, Double) 626 627 void CallStaticVoidMethod(jclass clazz, jmethodID methodID, ...) 628 { 629 va_list args; 630 va_start(args, methodID); 631 functions->CallStaticVoidMethodV(this, clazz, methodID, args); 632 va_end(args); 633 } 634 void CallStaticVoidMethodV(jclass clazz, jmethodID methodID, va_list args) 635 { functions->CallStaticVoidMethodV(this, clazz, methodID, args); } 636 void CallStaticVoidMethodA(jclass clazz, jmethodID methodID, jvalue* args) 637 { functions->CallStaticVoidMethodA(this, clazz, methodID, args); } 638 639 jfieldID GetStaticFieldID(jclass clazz, const char* name, const char* sig) 640 { return functions->GetStaticFieldID(this, clazz, name, sig); } 641 642 jobject GetStaticObjectField(jclass clazz, jfieldID fieldID) 643 { return functions->GetStaticObjectField(this, clazz, fieldID); } 644 jboolean GetStaticBooleanField(jclass clazz, jfieldID fieldID) 645 { return functions->GetStaticBooleanField(this, clazz, fieldID); } 646 jbyte GetStaticByteField(jclass clazz, jfieldID fieldID) 647 { return functions->GetStaticByteField(this, clazz, fieldID); } 648 jchar GetStaticCharField(jclass clazz, jfieldID fieldID) 649 { return functions->GetStaticCharField(this, clazz, fieldID); } 650 jshort GetStaticShortField(jclass clazz, jfieldID fieldID) 651 { return functions->GetStaticShortField(this, clazz, fieldID); } 652 jint GetStaticIntField(jclass clazz, jfieldID fieldID) 653 { return functions->GetStaticIntField(this, clazz, fieldID); } 654 jlong GetStaticLongField(jclass clazz, jfieldID fieldID) 655 { return functions->GetStaticLongField(this, clazz, fieldID); } 656 jfloat GetStaticFloatField(jclass clazz, jfieldID fieldID) 657 { return functions->GetStaticFloatField(this, clazz, fieldID); } 658 jdouble GetStaticDoubleField(jclass clazz, jfieldID fieldID) 659 { return functions->GetStaticDoubleField(this, clazz, fieldID); } 660 661 void SetStaticObjectField(jclass clazz, jfieldID fieldID, jobject value) 662 { functions->SetStaticObjectField(this, clazz, fieldID, value); } 663 void SetStaticBooleanField(jclass clazz, jfieldID fieldID, jboolean value) 664 { functions->SetStaticBooleanField(this, clazz, fieldID, value); } 665 void SetStaticByteField(jclass clazz, jfieldID fieldID, jbyte value) 666 { functions->SetStaticByteField(this, clazz, fieldID, value); } 667 void SetStaticCharField(jclass clazz, jfieldID fieldID, jchar value) 668 { functions->SetStaticCharField(this, clazz, fieldID, value); } 669 void SetStaticShortField(jclass clazz, jfieldID fieldID, jshort value) 670 { functions->SetStaticShortField(this, clazz, fieldID, value); } 671 void SetStaticIntField(jclass clazz, jfieldID fieldID, jint value) 672 { functions->SetStaticIntField(this, clazz, fieldID, value); } 673 void SetStaticLongField(jclass clazz, jfieldID fieldID, jlong value) 674 { functions->SetStaticLongField(this, clazz, fieldID, value); } 675 void SetStaticFloatField(jclass clazz, jfieldID fieldID, jfloat value) 676 { functions->SetStaticFloatField(this, clazz, fieldID, value); } 677 void SetStaticDoubleField(jclass clazz, jfieldID fieldID, jdouble value) 678 { functions->SetStaticDoubleField(this, clazz, fieldID, value); } 679 680 jstring NewString(const jchar* unicodeChars, jsize len) 681 { return functions->NewString(this, unicodeChars, len); } 682 683 jsize GetStringLength(jstring string) 684 { return functions->GetStringLength(this, string); } 685 686 const jchar* GetStringChars(jstring string, jboolean* isCopy) 687 { return functions->GetStringChars(this, string, isCopy); } 688 689 void ReleaseStringChars(jstring string, const jchar* chars) 690 { functions->ReleaseStringChars(this, string, chars); } 691 692 jstring NewStringUTF(const char* bytes) 693 { return functions->NewStringUTF(this, bytes); } 694 695 jsize GetStringUTFLength(jstring string) 696 { return functions->GetStringUTFLength(this, string); } 697 698 const char* GetStringUTFChars(jstring string, jboolean* isCopy) 699 { return functions->GetStringUTFChars(this, string, isCopy); } 700 701 void ReleaseStringUTFChars(jstring string, const char* utf) 702 { functions->ReleaseStringUTFChars(this, string, utf); } 703 704 jsize GetArrayLength(jarray array) 705 { return functions->GetArrayLength(this, array); } 706 707 jobjectArray NewObjectArray(jsize length, jclass elementClass, 708 jobject initialElement) 709 { return functions->NewObjectArray(this, length, elementClass, 710 initialElement); } 711 712 jobject GetObjectArrayElement(jobjectArray array, jsize index) 713 { return functions->GetObjectArrayElement(this, array, index); } 714 715 void SetObjectArrayElement(jobjectArray array, jsize index, jobject value) 716 { functions->SetObjectArrayElement(this, array, index, value); } 717 718 jbooleanArray NewBooleanArray(jsize length) 719 { return functions->NewBooleanArray(this, length); } 720 jbyteArray NewByteArray(jsize length) 721 { return functions->NewByteArray(this, length); } 722 jcharArray NewCharArray(jsize length) 723 { return functions->NewCharArray(this, length); } 724 jshortArray NewShortArray(jsize length) 725 { return functions->NewShortArray(this, length); } 726 jintArray NewIntArray(jsize length) 727 { return functions->NewIntArray(this, length); } 728 jlongArray NewLongArray(jsize length) 729 { return functions->NewLongArray(this, length); } 730 jfloatArray NewFloatArray(jsize length) 731 { return functions->NewFloatArray(this, length); } 732 jdoubleArray NewDoubleArray(jsize length) 733 { return functions->NewDoubleArray(this, length); } 734 735 jboolean* GetBooleanArrayElements(jbooleanArray array, jboolean* isCopy) 736 { return functions->GetBooleanArrayElements(this, array, isCopy); } 737 jbyte* GetByteArrayElements(jbyteArray array, jboolean* isCopy) 738 { return functions->GetByteArrayElements(this, array, isCopy); } 739 jchar* GetCharArrayElements(jcharArray array, jboolean* isCopy) 740 { return functions->GetCharArrayElements(this, array, isCopy); } 741 jshort* GetShortArrayElements(jshortArray array, jboolean* isCopy) 742 { return functions->GetShortArrayElements(this, array, isCopy); } 743 jint* GetIntArrayElements(jintArray array, jboolean* isCopy) 744 { return functions->GetIntArrayElements(this, array, isCopy); } 745 jlong* GetLongArrayElements(jlongArray array, jboolean* isCopy) 746 { return functions->GetLongArrayElements(this, array, isCopy); } 747 jfloat* GetFloatArrayElements(jfloatArray array, jboolean* isCopy) 748 { return functions->GetFloatArrayElements(this, array, isCopy); } 749 jdouble* GetDoubleArrayElements(jdoubleArray array, jboolean* isCopy) 750 { return functions->GetDoubleArrayElements(this, array, isCopy); } 751 752 void ReleaseBooleanArrayElements(jbooleanArray array, jboolean* elems, 753 jint mode) 754 { functions->ReleaseBooleanArrayElements(this, array, elems, mode); } 755 void ReleaseByteArrayElements(jbyteArray array, jbyte* elems, 756 jint mode) 757 { functions->ReleaseByteArrayElements(this, array, elems, mode); } 758 void ReleaseCharArrayElements(jcharArray array, jchar* elems, 759 jint mode) 760 { functions->ReleaseCharArrayElements(this, array, elems, mode); } 761 void ReleaseShortArrayElements(jshortArray array, jshort* elems, 762 jint mode) 763 { functions->ReleaseShortArrayElements(this, array, elems, mode); } 764 void ReleaseIntArrayElements(jintArray array, jint* elems, 765 jint mode) 766 { functions->ReleaseIntArrayElements(this, array, elems, mode); } 767 void ReleaseLongArrayElements(jlongArray array, jlong* elems, 768 jint mode) 769 { functions->ReleaseLongArrayElements(this, array, elems, mode); } 770 void ReleaseFloatArrayElements(jfloatArray array, jfloat* elems, 771 jint mode) 772 { functions->ReleaseFloatArrayElements(this, array, elems, mode); } 773 void ReleaseDoubleArrayElements(jdoubleArray array, jdouble* elems, 774 jint mode) 775 { functions->ReleaseDoubleArrayElements(this, array, elems, mode); } 776 777 void GetBooleanArrayRegion(jbooleanArray array, jsize start, jsize len, 778 jboolean* buf) 779 { functions->GetBooleanArrayRegion(this, array, start, len, buf); } 780 void GetByteArrayRegion(jbyteArray array, jsize start, jsize len, 781 jbyte* buf) 782 { functions->GetByteArrayRegion(this, array, start, len, buf); } 783 void GetCharArrayRegion(jcharArray array, jsize start, jsize len, 784 jchar* buf) 785 { functions->GetCharArrayRegion(this, array, start, len, buf); } 786 void GetShortArrayRegion(jshortArray array, jsize start, jsize len, 787 jshort* buf) 788 { functions->GetShortArrayRegion(this, array, start, len, buf); } 789 void GetIntArrayRegion(jintArray array, jsize start, jsize len, 790 jint* buf) 791 { functions->GetIntArrayRegion(this, array, start, len, buf); } 792 void GetLongArrayRegion(jlongArray array, jsize start, jsize len, 793 jlong* buf) 794 { functions->GetLongArrayRegion(this, array, start, len, buf); } 795 void GetFloatArrayRegion(jfloatArray array, jsize start, jsize len, 796 jfloat* buf) 797 { functions->GetFloatArrayRegion(this, array, start, len, buf); } 798 void GetDoubleArrayRegion(jdoubleArray array, jsize start, jsize len, 799 jdouble* buf) 800 { functions->GetDoubleArrayRegion(this, array, start, len, buf); } 801 802 void SetBooleanArrayRegion(jbooleanArray array, jsize start, jsize len, 803 const jboolean* buf) 804 { functions->SetBooleanArrayRegion(this, array, start, len, buf); } 805 void SetByteArrayRegion(jbyteArray array, jsize start, jsize len, 806 const jbyte* buf) 807 { functions->SetByteArrayRegion(this, array, start, len, buf); } 808 void SetCharArrayRegion(jcharArray array, jsize start, jsize len, 809 const jchar* buf) 810 { functions->SetCharArrayRegion(this, array, start, len, buf); } 811 void SetShortArrayRegion(jshortArray array, jsize start, jsize len, 812 const jshort* buf) 813 { functions->SetShortArrayRegion(this, array, start, len, buf); } 814 void SetIntArrayRegion(jintArray array, jsize start, jsize len, 815 const jint* buf) 816 { functions->SetIntArrayRegion(this, array, start, len, buf); } 817 void SetLongArrayRegion(jlongArray array, jsize start, jsize len, 818 const jlong* buf) 819 { functions->SetLongArrayRegion(this, array, start, len, buf); } 820 void SetFloatArrayRegion(jfloatArray array, jsize start, jsize len, 821 const jfloat* buf) 822 { functions->SetFloatArrayRegion(this, array, start, len, buf); } 823 void SetDoubleArrayRegion(jdoubleArray array, jsize start, jsize len, 824 const jdouble* buf) 825 { functions->SetDoubleArrayRegion(this, array, start, len, buf); } 826 827 jint RegisterNatives(jclass clazz, const JNINativeMethod* methods, 828 jint nMethods) 829 { return functions->RegisterNatives(this, clazz, methods, nMethods); } 830 831 jint UnregisterNatives(jclass clazz) 832 { return functions->UnregisterNatives(this, clazz); } 833 834 jint MonitorEnter(jobject obj) 835 { return functions->MonitorEnter(this, obj); } 836 837 jint MonitorExit(jobject obj) 838 { return functions->MonitorExit(this, obj); } 839 840 jint GetJavaVM(JavaVM** vm) 841 { return functions->GetJavaVM(this, vm); } 842 843 void GetStringRegion(jstring str, jsize start, jsize len, jchar* buf) 844 { functions->GetStringRegion(this, str, start, len, buf); } 845 846 void GetStringUTFRegion(jstring str, jsize start, jsize len, char* buf) 847 { return functions->GetStringUTFRegion(this, str, start, len, buf); } 848 849 void* GetPrimitiveArrayCritical(jarray array, jboolean* isCopy) 850 { return functions->GetPrimitiveArrayCritical(this, array, isCopy); } 851 852 void ReleasePrimitiveArrayCritical(jarray array, void* carray, jint mode) 853 { functions->ReleasePrimitiveArrayCritical(this, array, carray, mode); } 854 855 const jchar* GetStringCritical(jstring string, jboolean* isCopy) 856 { return functions->GetStringCritical(this, string, isCopy); } 857 858 void ReleaseStringCritical(jstring string, const jchar* carray) 859 { functions->ReleaseStringCritical(this, string, carray); } 860 861 jweak NewWeakGlobalRef(jobject obj) 862 { return functions->NewWeakGlobalRef(this, obj); } 863 864 void DeleteWeakGlobalRef(jweak obj) 865 { functions->DeleteWeakGlobalRef(this, obj); } 866 867 jboolean ExceptionCheck() 868 { return functions->ExceptionCheck(this); } 869 870 jobject NewDirectByteBuffer(void* address, jlong capacity) 871 { return functions->NewDirectByteBuffer(this, address, capacity); } 872 873 void* GetDirectBufferAddress(jobject buf) 874 { return functions->GetDirectBufferAddress(this, buf); } 875 876 jlong GetDirectBufferCapacity(jobject buf) 877 { return functions->GetDirectBufferCapacity(this, buf); } 878 879 /* added in JNI 1.6 */ 880 jobjectRefType GetObjectRefType(jobject obj) 881 { return functions->GetObjectRefType(this, obj); } 882 #endif /*__cplusplus*/ 883 };
总结一下：
系统注册或者自己注册的JNI，通过JNIEnv对象中的本地接口表函数RegisterNative注册JNI方法，使用其中的CallVoidMethod系列函数调用JNI方法。
此文为学习JNI注册、调用过程，有错误的地方请大家指出谢谢！