Android的jni的调用C,C++的几个应用(基本类型，数组，类(结构体))

今天是母亲节，首先祝愿全天下的母亲健康长寿！永远年轻！天天快乐！
慈母手中线，游子身上衣，临行密密缝，意恐迟迟归，谁言寸草心，报得三春晖。
谢谢妈妈--jernymy

 

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开始正题啦，前些天在研究Andorid中Jni(Java Native Interface)的使用，
主要是在android中调用C、C++的方法，在网上也搜集了一些文档，源码等资料，非常感谢网友的提供的宝贵经验。
也是写下这个文章，希望可以帮助正在做这方面应用网友们，jni使用c语言。

一、首先软件环境要搭配好，本人使用的环境是
Android2.2的SDK+NDK4b，linux下的编译环境
1. Windows XP
2. VMware 7.1.3 build-324285 + Ubuntu 9.04中文版
3. Android SDK 2.2

4. Android NDK r4b Linux版(crystax)，加入支持C++ exceptions, RTTI and Standard C++ Library
http://www.crystax.net/android/ndk-r4.php
http://www.crystax.net/data/android-ndk-r4-linux-x86-crystax-4.tar.bz2

5. Eclipse Version: 3.5.2
eclipse3.5.2官方下载地址
http://archive.eclipse.org/eclipse/downloads/drops/R-3.5.2-201002111343/eclipse-SDK-3.5.2-win32.zip

6.

二、配置好eclipse，并加入androiddSDK，然后通过eclipse建立一个android工程，搭建android的jni框架
1. Eclipse
File->New->Android Project
如果此地没有Android Project，可以通过File->New->Project...，在弹出的对话框中，选择(Android)
以下几项填写，其他的默认即可
Project name:     AndroidJni
Build Target:     Android 2.2
Application name: AndroidJni
Package name:     com.jni
Create Activity:  AndroidJni
Min SDK Version:  8
点击Finish即可

此时，我们就可以看到我们的项目了
在src->com.jni下自动生成的AndroidJni.java内容如下

package com.jni;import android.app.Activity;import android.os.Bundle;public class AndroidJni extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); }}

 

 

我们在这里新建立一个class，比如命名jernymyjni，
这个作为我们的Jni的所有接口处，作为测试设计了基本类型，数组，和类(结构体)，结构体数组等。
代码如下package com.jni;// jernymy use c style for var namepublic class jernymyjni {char chChar; // char use ch token//short wShort; // short use w token, short same as intint nInt; // int use n tokenString sString; // String use s token/*-------- jernymy for base type declaration start --------*//* * The char process method GetChar * @param char chInput : the input char for process * @return(char) : input char (chInput) upper or lower * @author : jernymy * @date : 20110508 * */public native char GetChar(char chInput);/* * The char process method SetChar * @param char chInput : set the input char * @return(int) : status, 0-OK, other-Error * @author : jernymy * @date : 20110508 * */public native int SetChar(char chInput);/* * The int process method GetInt * @param int nAdd1 : add one * @param int nAdd2 : add other * @return(int) : sum of two add var * @author : jernymy * @date : 20110508 * */public native int GetInt(int nAdd1, int nAdd2);/* * The int process method SetInt * @param int nSet : set one int data * @return(int) : status, 0-OK, other-Error * @author : jernymy * @date : 20110508 * */public native int SetInt(int nSet);/* * The String process method GetStr * @return(String) : the string for use * @author : jernymy * @date : 20110508 * */public native String GetStr();/* * The String process method PrcsStr * @param String sInput : the input String for process * @return(String) : the process of the input String * @author : jernymy * @date : 20110508 * */public native String PrcsStr(String sInput);/* * The String process method PrcsStr * @param String sSet : the set String * @return(int) : status, 0-OK, other-Error * @author : jernymy * @date : 20110508 * */public native int SetStr(String sSet);/*-------- jernymy for base type declaration end --------*//*-------- jernymy for array type declaration start --------*//* * The char array process method GetCharArray * @param char chSet : the chSet char for process * @return(char[]) : char array, upper and lower * @author : jernymy * @date : 20110508 * */public native char[] GetCharArray(char chSet);/* * The char array process method SetCharArray * @param char[] chSet : the chSet char array for process * @return(int) : status, 0-OK, other-Error * @author : jernymy * @date : 20110508 * */public native int SetCharArray(char[] chSet);/* * The int array process method GetIntArray * @param int[] nAdd1 : add one array * @param int[] nAdd2 : add other array * @return(int[]) : sum array of two add array var * @author : jernymy * @date : 20110508 * */public native int[] GetIntArray(int[] nAdd1, int[] nAdd2);/* * The int array process method SetIntArray * @param int[] nSet : set one int array data * @return(int) : status, 0-OK, other-Error * @author : jernymy * @date : 20110508 * */public native int SetIntArray(int[] nSet);/* * The String array process method GetStrArray * @return(String[]) : String array with null parameter * @author : jernymy * @date : 20110508 * */public native String[] GetStrArray();/* * The String array process method PrcsStrArray * @param String sSet : the string with " " token sSet * @return(String[]) : ervey string by " " token * @author : jernymy * @date : 20110508 * */public native String[] PrcsStrArray(String sSet);/* * The String array process method SetStrArray * @param String[] sSet : set the string array * @return(int) : status, 0-OK, other-Error * @author : jernymy * @date : 20110508 * */public native int SetStrArray(String[] sSet);/*-------- jernymy for array type declaration end --------*//*-------- jernymy for class(struct) type declaration start --------*//* * The jernymyjni class(struct) process method GetClass * @param int nIdx : get class data by index * @return(jernymyjni) : status, 0-OK, other-Error * @author : jernymy * @date : 20110508 * */public native jernymyjni GetClass(int nIdx);/* * The jernymyjni class(struct) process method SetClass * @param jernymyjni cClass : set class data by class index * @return(int) : status, 0-OK, other-Error * @author : jernymy * @date : 20110508 * */public native int SetClass(jernymyjni cClass);/*-------- jernymy for class(struct) type declaration end --------*//*-------- jernymy for class(struct) array type declaration start --------*//* * The jernymyjni class(struct) array process method GetClassArray * @return(jernymyjni[]) : class array data * @author : jernymy * @date : 20110508 * */public native jernymyjni[] GetClassArray();/* * The jernymyjni class(struct) array process method SetClassArray * @param jernymyjni[] cNcomnAry : set class array data * @return(int) : status, 0-OK, other-Error * @author : jernymy * @date : 20110508 * */public native int SetClassArray(jernymyjni[] acClassAry);/*-------- jernymy for class(struct) array type declaration end --------*/static{System.loadLibrary("jernymyjni"); // jernymy here is the so name}}

 

 

 

通过eclipse的生成对应的class文件，会在AndroidJni/bin下生成所有的文件

然后进入windowsXP的command模式
开始->运行->cmd
到我们的项目的所在目录，我的目录为
运行javah，得到对应的jni的头文件
E:/work/jave/workspace/AndroidJni>javah -classpath bin com.jni.jernymyjni

E:/work/jave/workspace/AndroidJni>
此时会在当前目录下生成一个com_jni_jernymyjni.h，好了，就是它了，接下来开始编写它对应的c文件了。
为了符合android的文档规范，我们需要在当前目录(AndroidJni)下先建立一个jni目录，然后再建立一个Android.mk
然后把com_jni_jernymyjni.h文件copy到jni目录下。

E:/work/jave/workspace/AndroidJni>cd jni

E:/work/jave/workspace/AndroidJni/jni>dir
 驱动器 E 中的卷是 work
 卷的序列号是 1C8F-CA73

 E:/work/jave/workspace/AndroidJni/jni 的目录

2011-05-08  23:09    <DIR>          .
2011-05-08  23:09    <DIR>          ..
2011-05-08  23:08                 0 Android.mk
2011-05-08  22:58             3,802 com_jni_jernymyjni.h
               2 个文件          3,802 字节
               2 个目录 10,864,427,008 可用字节

E:/work/jave/workspace/AndroidJni/jni>

 

com_jni_jernymyjni.h的文件内容
/* DO NOT EDIT THIS FILE - it is machine generated */#include <jni.h>/* Header for class com_jni_jernymyjni */#ifndef _Included_com_jni_jernymyjni#define _Included_com_jni_jernymyjni#ifdef __cplusplusextern "C" {#endif/* * Class: com_jni_jernymyjni * Method: GetChar * Signature: (C)C */JNIEXPORT jchar JNICALL Java_com_jni_jernymyjni_GetChar (JNIEnv *, jobject, jchar);/* * Class: com_jni_jernymyjni * Method: SetChar * Signature: (C)I */JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetChar (JNIEnv *, jobject, jchar);/* * Class: com_jni_jernymyjni * Method: GetInt * Signature: (II)I */JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_GetInt (JNIEnv *, jobject, jint, jint);/* * Class: com_jni_jernymyjni * Method: SetInt * Signature: (I)I */JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetInt (JNIEnv *, jobject, jint);/* * Class: com_jni_jernymyjni * Method: GetStr * Signature: ()Ljava/lang/String; */JNIEXPORT jstring JNICALL Java_com_jni_jernymyjni_GetStr (JNIEnv *, jobject);/* * Class: com_jni_jernymyjni * Method: PrcsStr * Signature: (Ljava/lang/String;)Ljava/lang/String; */JNIEXPORT jstring JNICALL Java_com_jni_jernymyjni_PrcsStr (JNIEnv *, jobject, jstring);/* * Class: com_jni_jernymyjni * Method: SetStr * Signature: (Ljava/lang/String;)I */JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetStr (JNIEnv *, jobject, jstring);/* * Class: com_jni_jernymyjni * Method: GetCharArray * Signature: (C)[C */JNIEXPORT jcharArray JNICALL Java_com_jni_jernymyjni_GetCharArray (JNIEnv *, jobject, jchar);/* * Class: com_jni_jernymyjni * Method: SetCharArray * Signature: ([C)I */JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetCharArray (JNIEnv *, jobject, jcharArray);/* * Class: com_jni_jernymyjni * Method: GetIntArray * Signature: ([I[I)[I */JNIEXPORT jintArray JNICALL Java_com_jni_jernymyjni_GetIntArray (JNIEnv *, jobject, jintArray, jintArray);/* * Class: com_jni_jernymyjni * Method: SetIntArray * Signature: ([I)I */JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetIntArray (JNIEnv *, jobject, jintArray);/* * Class: com_jni_jernymyjni * Method: GetStrArray * Signature: ()[Ljava/lang/String; */JNIEXPORT jobjectArray JNICALL Java_com_jni_jernymyjni_GetStrArray (JNIEnv *, jobject);/* * Class: com_jni_jernymyjni * Method: PrcsStrArray * Signature: (Ljava/lang/String;)[Ljava/lang/String; */JNIEXPORT jobjectArray JNICALL Java_com_jni_jernymyjni_PrcsStrArray (JNIEnv *, jobject, jstring);/* * Class: com_jni_jernymyjni * Method: SetStrArray * Signature: ([Ljava/lang/String;)I */JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetStrArray (JNIEnv *, jobject, jobjectArray);/* * Class: com_jni_jernymyjni * Method: GetClass * Signature: (I)Lcom/jni/jernymyjni; */JNIEXPORT jobject JNICALL Java_com_jni_jernymyjni_GetClass (JNIEnv *, jobject, jint);/* * Class: com_jni_jernymyjni * Method: SetClass * Signature: (Lcom/jni/jernymyjni;)I */JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetClass (JNIEnv *, jobject, jobject);/* * Class: com_jni_jernymyjni * Method: GetClassArray * Signature: ()[Lcom/jni/jernymyjni; */JNIEXPORT jobjectArray JNICALL Java_com_jni_jernymyjni_GetClassArray (JNIEnv *, jobject);/* * Class: com_jni_jernymyjni * Method: SetClassArray * Signature: ([Lcom/jni/jernymyjni;)I */JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetClassArray (JNIEnv *, jobject, jobjectArray);#ifdef __cplusplus}#endif#endif

 

com_jni_jernymyjni.c的文件内容

#include "com_jni_jernymyjni.h"#include "stdio.h" // printf#include "string.h" // strlen, memset...#define JNI_ERR_NULL_CLASS 0x10#define JNI_ERR_NULL_CHAR 0x11#define JNI_ERR_NULL_INT 0x12#define JNI_ERR_NULL_STR 0x13#define JNI_ERR_NULL_OBJ 0x14#define JNI_ERR_NULL_FIELD_CHAR 0x15#define JNI_ERR_NULL_FIELD_INT 0x16#define JNI_ERR_NULL_FIELD_OBJ 0x17#define JNI_ERR_NULL_STR_UTF_C 0x18#define JNI_ERR_NULL_OBJ_ARY_ELEMENT 0x19#define JNI_ERR_NULL_METHOD 0x20#define JNI_DBGprintf("[C]-File:%s, Line:%d/n", __FILE__, __LINE__);#define JNI_ASSERT_P_RTN_VAR(var, rtn)/ if (NULL == var)/{/printf("[C]-File:%s, Line:%d, %s==NULL/n", __FILE__, __LINE__, #var);/return rtn;/}#define JNI_ASSERT_V_RTN_VAR(var, rtn)/ if (0 == var)/{/printf("[C]-File:%s, Line:%d, %s==NULL/n", __FILE__, __LINE__, #var);/return rtn;/}FILE *fpJniDbg = NULL;// A[65], a[97]// (chA1 & (~0x20)) = tower, (chA1 | 0x20)upperJNIEXPORT jchar JNICALL Java_com_jni_jernymyjni_GetChar (JNIEnv *jpcEnv, jobject jcObj, jchar jchInput){if (jchInput >= 'a' && jchInput <= 'z'){return (jchInput & (~0x20));}else if (jchInput >= 'A' && jchInput <= 'Z'){return (jchInput | 0x20);}return 0;}JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetChar (JNIEnv *jpcEnv, jobject jcObj, jchar jchSet){printf("[C]-Line:%d-Java_com_jni_jernymyjni_SetChar-jchSet:%c/n",__LINE__, jchSet);return 0;}JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_GetInt (JNIEnv *jpcEnv, jobject jcObj, jint jnAdd1, jint jnAdd2){return (jnAdd1 + jnAdd2);}JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetInt (JNIEnv *jpcEnv, jobject jcObj, jint jnSet){printf("[C]-Line:%d-Java_com_jni_jernymyjni_SetInt-jnSet:%d/n",__LINE__, jnSet);return 0;}JNIEXPORT jstring JNICALL Java_com_jni_jernymyjni_GetStr (JNIEnv *jpcEnv, jobject jcObj){char *pachStr = {"Jernymy jni test"};return (*jpcEnv)->NewStringUTF(jpcEnv, pachStr);}JNIEXPORT jstring JNICALL Java_com_jni_jernymyjni_PrcsStr (JNIEnv *jpcEnv, jobject jcObj, jstring jsStr){int nLen = 0;char achBuf[128] = {0};const char *lpcstrGet = (*jpcEnv)->GetStringUTFChars(jpcEnv, jsStr, 0);nLen = strlen(lpcstrGet);nLen = (nLen > 127) ? 127 : nLen;strncpy(achBuf, lpcstrGet, nLen);(*jpcEnv)->ReleaseStringUTFChars(jpcEnv, jsStr, lpcstrGet);while (nLen--){ // swicth to upper, to lower (a &(~0x20))achBuf[nLen] = achBuf[nLen] | 0x20;}return (*jpcEnv)->NewStringUTF(jpcEnv, achBuf);}JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetStr (JNIEnv *jpcEnv, jobject jcObj, jstring jsStr){const char *lpcstrGet = (*jpcEnv)->GetStringUTFChars(jpcEnv, jsStr, 0);JNI_ASSERT_P_RTN_VAR(lpcstrGet, -1);printf("[C]-Line:%d-Java_com_jni_jernymyjni_SetStr-jsStr:%s/n",__LINE__, lpcstrGet);// release for memory(*jpcEnv)->ReleaseStringUTFChars(jpcEnv, jsStr, lpcstrGet);return 0;}#define CHAR_NUM 2JNIEXPORT jcharArray JNICALL Java_com_jni_jernymyjni_GetCharArray (JNIEnv *jpcEnv, jobject jcObj, jchar jchChar){ jobjectArray joArray = 0;jchar achBuf[CHAR_NUM] = {0};achBuf[0] = jchChar & (~0x20); // 'a'achBuf[1] = jchChar | 0x20; // 'A'joArray = (*jpcEnv)->NewCharArray(jpcEnv, CHAR_NUM);JNI_ASSERT_P_RTN_VAR(joArray, NULL);(*jpcEnv)->SetCharArrayRegion(jpcEnv, joArray, 0, 2, achBuf);return joArray;}JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetCharArray (JNIEnv *jpcEnv, jobject jcObj, jcharArray jchCharArray){jsize jsLen = (*jpcEnv)->GetArrayLength(jpcEnv, jchCharArray); // get array lengthprintf("[C]-Line:%d-Java_com_jni_jernymyjni_SetCharArray-jsLen:%d,jchCharArray:%p/n",__LINE__, jsLen, jchCharArray);return 0;}JNIEXPORT jintArray JNICALL Java_com_jni_jernymyjni_GetIntArray (JNIEnv *jpcEnv, jobject jcObj, jintArray jiAry1, jintArray jiAry2){int nIdx;jint nSum[10] = {0}; jobjectArray joArray = 0;jsize jsLen = (*jpcEnv)->GetArrayLength(jpcEnv, jiAry1); // get array lengthjint *jpIAry1 = (*jpcEnv)->GetIntArrayElements(jpcEnv, jiAry1, 0); // get array element pointerjint *jpIAry2 = (*jpcEnv)->GetIntArrayElements(jpcEnv, jiAry2, 0); // get array element pointer// the value is now valid, so return NULLJNI_ASSERT_V_RTN_VAR(jsLen, NULL);JNI_ASSERT_P_RTN_VAR(jpIAry1, NULL);JNI_ASSERT_P_RTN_VAR(jpIAry2, NULL);printf("[C]-Line:%d-Java_com_jni_jernymyjni_GetIntArray-jiAry1 length:%d/n",__LINE__, jsLen);joArray = (*jpcEnv)->NewIntArray(jpcEnv, jsLen);JNI_ASSERT_P_RTN_VAR(joArray, NULL);for (nIdx = 0; nIdx < jsLen; nIdx++){nSum[nIdx] = jpIAry1[nIdx] + jpIAry2[nIdx]; // add every array elementprintf("[C]-nSum:%d=%d+%d/n", nSum[nIdx], jpIAry1[nIdx], jpIAry2[nIdx]);}(*jpcEnv)->SetIntArrayRegion(jpcEnv, joArray, 0, jsLen, nSum);(*jpcEnv)->ReleaseIntArrayElements(jpcEnv, jiAry1, jpIAry1, 0); // release, do not forget(*jpcEnv)->ReleaseIntArrayElements(jpcEnv, jiAry2, jpIAry2, 0); // release, do not forgetreturn joArray;}JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetIntArray (JNIEnv *jpcEnv, jobject jcObj, jintArray jiAry1){int nIdx;jsize jsLen = (*jpcEnv)->GetArrayLength(jpcEnv, jiAry1); // get array lengthjint *jpIAry1 = (*jpcEnv)->GetIntArrayElements(jpcEnv, jiAry1, 0); // get array pointerJNI_ASSERT_V_RTN_VAR(jsLen, 0);JNI_ASSERT_P_RTN_VAR(jpIAry1, 0);printf("[C]-Line:%d-Java_com_jni_jernymyjni_GetIntArray-jiAry1 length:%d/n",__LINE__, jsLen);for (nIdx = 0; nIdx < jsLen; nIdx++){printf("[C]-Index:%d, jpIAry1:%d/n", nIdx, jpIAry1[nIdx]);}(*jpcEnv)->ReleaseIntArrayElements(jpcEnv, jiAry1, jpIAry1, 0); // release, do not forgetreturn 0;}#define JNI_STR_ARRAY_NUM 3JNIEXPORT jobjectArray JNICALL Java_com_jni_jernymyjni_GetStrArray (JNIEnv *jpcEnv, jobject jcObj){jstring jsStr = 0;jclass jcStrCls = 0;jobjectArray joArray = 0;int nIdx = 0;char *pachStr[JNI_STR_ARRAY_NUM] = {"Jernymy", "Jni ", "Test"};jcStrCls = (*jpcEnv)->FindClass(jpcEnv, "java/lang/String");JNI_ASSERT_P_RTN_VAR(jcStrCls, NULL);joArray = (*jpcEnv)->NewObjectArray(jpcEnv, JNI_STR_ARRAY_NUM, jcStrCls, 0);JNI_ASSERT_P_RTN_VAR(joArray, NULL);for (; nIdx< JNI_STR_ARRAY_NUM; nIdx++){jsStr = (*jpcEnv)->NewStringUTF(jpcEnv, pachStr[nIdx]);JNI_ASSERT_P_RTN_VAR(jsStr, NULL);(*jpcEnv)->SetObjectArrayElement(jpcEnv, joArray, nIdx, jsStr);}return joArray;}JNIEXPORT jobjectArray JNICALL Java_com_jni_jernymyjni_PrcsStrArray (JNIEnv *jpcEnv, jobject jcObj, jstring jsString){ jobjectArray joArray = 0;jclass jcStrCls;jstring jsCurStr;const char *lpcstrGet;const char *lpcstrBk;char *pchStr;char achStrBuf[128] = {0};int nIndex = 0;pchStr = achStrBuf;#ifdef WIN32// OK success - win32 system// win32 "java/lang/String" and "Ljava/lang/String;" both OK//jclass jcStrCls = (*jpcEnv)->FindClass(jpcEnv, "java/lang/String");jcStrCls = (*jpcEnv)->FindClass(jpcEnv, "Ljava/lang/String;");#else// linux here must "java/lang/String"jcStrCls = (*jpcEnv)->FindClass(jpcEnv, "java/lang/String");/*----get string array:Exception in thread "main" java.lang.ClassNotFoundException: Ljava.lang.String; not found in gnu.gcj.runtime.SystemClassLoader{urls=[file:./], parent=gnu.gcj.runtime.ExtensionClassLoader{urls=[], parent=null}} at java.net.URLClassLoader.findClass(libgcj.so.7rh) at gnu.gcj.runtime.SystemClassLoader.findClass(libgcj.so.7rh) at java.lang.ClassLoader.loadClass(libgcj.so.7rh) at java.lang.ClassLoader.loadClass(libgcj.so.7rh)[yewu@localhost src]$ *///jclass jcStrCls = (*jpcEnv)->FindClass(jpcEnv, "Ljava/lang/String;");#endifJNI_ASSERT_P_RTN_VAR(jcStrCls, NULL);joArray = (*jpcEnv)->NewObjectArray(jpcEnv, 3, jcStrCls, 0);JNI_ASSERT_P_RTN_VAR(joArray, NULL);lpcstrGet = (*jpcEnv)->GetStringUTFChars(jpcEnv, jsString, 0);JNI_ASSERT_P_RTN_VAR(lpcstrGet, NULL);lpcstrBk = lpcstrGet;printf("[C]-lpcstrGet:%s/n", lpcstrGet);while (*lpcstrGet){if (' ' == *lpcstrGet){nIndex++;lpcstrGet++;printf("[C]-achStrBuf:%s/n", achStrBuf);jsCurStr = (*jpcEnv)->NewStringUTF(jpcEnv, achStrBuf);JNI_ASSERT_P_RTN_VAR(jsCurStr, NULL);(*jpcEnv)->SetObjectArrayElement(jpcEnv, joArray, nIndex-1, jsCurStr);memset(&achStrBuf, 0, 128);pchStr = &achStrBuf[0];}else{*pchStr++ = *lpcstrGet++;}}if (achStrBuf[0]){printf("[C]-achStrBuf:%s/n", achStrBuf);jsCurStr = (*jpcEnv)->NewStringUTF(jpcEnv, achStrBuf);JNI_ASSERT_P_RTN_VAR(jsCurStr, NULL);(*jpcEnv)->SetObjectArrayElement(jpcEnv, joArray, nIndex, jsCurStr);}(*jpcEnv)->ReleaseStringUTFChars(jpcEnv, jsString, lpcstrBk);return joArray;}JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetStrArray (JNIEnv *jpcEnv, jobject jcObj, jobjectArray jcObjAry){int nIdx;const char *lpcstrGet;jobject jcObjCur;int nLen = (*jpcEnv)->GetArrayLength(jpcEnv, jcObjAry);JNI_ASSERT_V_RTN_VAR(nLen, 0);printf("[C]-jcObjAry length:%d/n", nLen);for (nIdx = 0; nIdx < nLen; nIdx++){ jcObjCur = (*jpcEnv)->GetObjectArrayElement(jpcEnv, jcObjAry, nIdx);JNI_ASSERT_P_RTN_VAR(jcObjCur, 0); lpcstrGet = (*jpcEnv)->GetStringUTFChars(jpcEnv, (jstring)jcObjCur, 0 );JNI_ASSERT_P_RTN_VAR(lpcstrGet, 0); printf("[C]-index[%d] lpcstrGet:%s/n", nIdx, lpcstrGet); (*jpcEnv)->ReleaseStringUTFChars(jpcEnv, jcObjCur, lpcstrGet);}printf("[C]-/n");return 0;}JNIEXPORT jobject JNICALL Java_com_jni_jernymyjni_GetClass (JNIEnv *jpcEnv, jobject jcObj, jint jnIdx){char achBuf[32] = {0};jclass jcStruct;jfieldID jchChar;jfieldID jnInt;jfieldID jsString;jstring jsStr;jobject joCurObj;jmethodID jmId;jcStruct = (*jpcEnv)->FindClass(jpcEnv, "com/jni/jernymyjni");JNI_ASSERT_P_RTN_VAR(jcStruct, NULL);jchChar = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "chChar", "C");JNI_ASSERT_P_RTN_VAR(jchChar, NULL);jnInt = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "nInt", "I");JNI_ASSERT_P_RTN_VAR(jnInt, NULL);#ifdef WIN32jsString = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "sString", "Ljava/lang/String;");#elsejsString = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "sString", "Ljava/lang/String;");//jsString = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "sString", "java/lang/String");#endifJNI_ASSERT_P_RTN_VAR(jsString, NULL);// get class init methodjmId = (*jpcEnv)->GetMethodID(jpcEnv, jcStruct, "<init>", "()V");JNI_ASSERT_P_RTN_VAR(jsString, NULL);joCurObj = (*jpcEnv)->NewObject(jpcEnv, jcStruct, jmId);JNI_ASSERT_P_RTN_VAR(joCurObj, NULL);(*jpcEnv)->SetCharField(jpcEnv, joCurObj, jchChar, (char)(1+'d'));(*jpcEnv)->SetIntField(jpcEnv, joCurObj, jnInt, 0);sprintf(achBuf, "****sString[%d]%c", 0, 0);jsStr = (*jpcEnv)->NewStringUTF(jpcEnv, achBuf);JNI_ASSERT_P_RTN_VAR(jsStr, NULL);(*jpcEnv)->SetObjectField(jpcEnv, joCurObj, jsString, jsStr);printf("[C]-----%d, %c, %s/n", 0, 1+'0', achBuf);return joCurObj;}JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetClass (JNIEnv *jpcEnv, jobject jcObj, jobject jcSetStruct){const char *lpcstrGet;jchar jchData;jint jnData;jobject jcObjStr;jfieldID jchChar;jfieldID jnInt;jfieldID jsString;jclass jcStruct;// here is the class name, java file create a com_jni_jernymyjni class, so name isjcStruct = (*jpcEnv)->FindClass(jpcEnv, "com/jni/jernymyjni");JNI_ASSERT_P_RTN_VAR(jcStruct, JNI_ERR_NULL_CLASS);// char sig is "C", see the .h file, Signature: (C)[CjchChar = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "chChar", "C");JNI_ASSERT_P_RTN_VAR(jchChar, JNI_ERR_NULL_CHAR);// int sig is "I", see the .h file, Signature: ([I[I)[IjnInt = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "nInt", "I");JNI_ASSERT_P_RTN_VAR(jnInt, JNI_ERR_NULL_INT);// string, see the .h file, Signature: (Ljava/lang/String;)[Ljava/lang/String;jsString = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "sString", "Ljava/lang/String;");JNI_ASSERT_P_RTN_VAR(jsString, JNI_ERR_NULL_STR);// get char field informationjchData = (*jpcEnv)->GetCharField(jpcEnv, jcSetStruct, jchChar);printf("[C]-jchData:%c/n", jchData);// get int field informationjnData = (*jpcEnv)->GetIntField(jpcEnv, jcSetStruct, jnInt);printf("[C]-jnData:%d/n", jnData);// get object field , now is string informationjcObjStr = (*jpcEnv)->GetObjectField(jpcEnv, jcSetStruct, jsString);JNI_ASSERT_P_RTN_VAR(jcObjStr, JNI_ERR_NULL_FIELD_OBJ);// get const char information from jstringlpcstrGet = (*jpcEnv)->GetStringUTFChars(jpcEnv, (jstring)jcObjStr, 0);JNI_ASSERT_P_RTN_VAR(lpcstrGet, JNI_ERR_NULL_STR_UTF_C);printf("[C]-lpcstrGet:%s/n", lpcstrGet);// release const char information from jstring (*jpcEnv)->ReleaseStringUTFChars(jpcEnv, jcObjStr, lpcstrGet);printf("[C]-/n");return 0;}#define STRUCT_ARRAY_NUM 3JNIEXPORT jobjectArray JNICALL Java_com_jni_jernymyjni_GetClassArray (JNIEnv *jpcEnv, jobject jcObj){int nIdx;char achBuf[32] = {0};jclass jcStruct;jobjectArray jcAry;jfieldID jnInt;jfieldID jchChar;jfieldID jsString;jstring jsStr;jobject joCurObj;jmethodID jmId;// here is the class name, java file create a com_jni_jernymyjni class, so name isjcStruct = (*jpcEnv)->FindClass(jpcEnv, "com/jni/jernymyjni");JNI_ASSERT_P_RTN_VAR(jcStruct, NULL);// how many array will create, now is 3, and init is 0;jcAry = (*jpcEnv)->NewObjectArray(jpcEnv, STRUCT_ARRAY_NUM, jcStruct, 0);JNI_ASSERT_P_RTN_VAR(jcAry, NULL);// char sig is "C", see the .h file, Signature: (C)[CjchChar = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "chChar", "C");JNI_ASSERT_P_RTN_VAR(jchChar, NULL);// int sig is "I", see the .h file, Signature: ([I[I)[IjnInt = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "nInt", "I");JNI_ASSERT_P_RTN_VAR(jnInt, NULL);// string, see the .h file, Signature: (Ljava/lang/String;)[Ljava/lang/String;jsString = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "sString", "Ljava/lang/String;");JNI_ASSERT_P_RTN_VAR(jsString, NULL);// get class method, 得到类的构造函数jmId = (*jpcEnv)->GetMethodID(jpcEnv, jcStruct, "<init>", "()V");JNI_ASSERT_P_RTN_VAR(jmId, NULL);for (nIdx = 0; nIdx < STRUCT_ARRAY_NUM; nIdx++){// create a new object area, like malloc or alloc bufferjoCurObj = (*jpcEnv)->NewObject(jpcEnv, jcStruct, jmId);JNI_ASSERT_P_RTN_VAR(joCurObj, NULL);// set the char value(*jpcEnv)->SetCharField(jpcEnv, joCurObj, jchChar, (char)(nIdx+'a'));// set the int value(*jpcEnv)->SetIntField(jpcEnv, joCurObj, jnInt, nIdx);sprintf(achBuf, "****sString[%d]%c", nIdx, 0);// get jstring with achBufjsStr = (*jpcEnv)->NewStringUTF(jpcEnv, achBuf);JNI_ASSERT_P_RTN_VAR(jsStr, NULL);// set the string value(*jpcEnv)->SetObjectField(jpcEnv, joCurObj, jsString, jsStr);printf("[C]-Line:%d-Java_com_jni_jernymyjni_GetClassArray/n", __LINE__);printf("[C]-----%d, %c, %s/n", nIdx, 'd', achBuf);// set all struct value with index(*jpcEnv)->SetObjectArrayElement(jpcEnv, jcAry, nIdx, joCurObj);}return jcAry;}JNIEXPORT jint JNICALL Java_com_jni_jernymyjni_SetClassArray (JNIEnv *jpcEnv, jobject jcObj, jobjectArray jcObjAry){int nIdx;const char *lpcstrGet;jobject jcObjCur;jchar jchData;jint jnData;jobject jcObjStr;jfieldID jchChar;jfieldID jnInt;jfieldID jsString;jclass jcStruct;int nLen = (*jpcEnv)->GetArrayLength(jpcEnv, jcObjAry);// here is the class name, java file create a com_jni_jernymyjni class, so name isjcStruct = (*jpcEnv)->FindClass(jpcEnv, "com/jni/jernymyjni");JNI_ASSERT_P_RTN_VAR(jcStruct, JNI_ERR_NULL_CLASS);// char sig is "C", see the .h file, Signature: (C)[CjchChar = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "chChar", "C");// int sig is "I", see the .h file, Signature: ([I[I)[IjnInt = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "nInt", "I");JNI_ASSERT_P_RTN_VAR(jnInt, JNI_ERR_NULL_INT);// string, see the .h file, Signature: (Ljava/lang/String;)[Ljava/lang/String;jsString = (*jpcEnv)->GetFieldID(jpcEnv, jcStruct, "sString", "Ljava/lang/String;");JNI_ASSERT_P_RTN_VAR(jsString, JNI_ERR_NULL_STR);printf("[C]-jcObjAry length:%d/n", nLen);for (nIdx = 0; nIdx < nLen; nIdx++){ printf("[C]-index[%d]", nIdx);// get every object information jcObjCur = (*jpcEnv)->GetObjectArrayElement(jpcEnv, jcObjAry, nIdx);JNI_ASSERT_P_RTN_VAR(jcObjStr, JNI_ERR_NULL_OBJ_ARY_ELEMENT);// get char field informationjchData = (*jpcEnv)->GetCharField(jpcEnv, jcObjCur, jchChar);//JNI_ASSERT_V_RTN_VAR(jchData, JNI_ERR_NULL_FIELD_CHAR);printf("[C]-jchData:%c/n", jchData);// get int field informationjnData = (*jpcEnv)->GetIntField(jpcEnv, jcObjCur, jnInt);printf("[C]-jnData:%d/n", jnData);// get object field , now is string informationjcObjStr = (*jpcEnv)->GetObjectField(jpcEnv, jcObjCur, jsString);JNI_ASSERT_P_RTN_VAR(jcObjStr, JNI_ERR_NULL_FIELD_OBJ);// get const char information from jstringlpcstrGet = (*jpcEnv)->GetStringUTFChars(jpcEnv, (jstring)jcObjStr, 0);JNI_ASSERT_P_RTN_VAR(lpcstrGet, JNI_ERR_NULL_STR_UTF_C);printf("[C]-lpcstrGet:%s/n", lpcstrGet);// release const char information from jstring (*jpcEnv)->ReleaseStringUTFChars(jpcEnv, jcObjStr, lpcstrGet);}printf("[C]-/n");return 0;}

 

 

编写Android.mk，内容如下

# Android.mk by jernymy, 20110508LOCAL_PATH := $(call my-dir)include $(CLEAR_VARS)LOCAL_MODULE := jernymyjniLOCAL_SRC_FILES := com_jni_jernymyjni.cinclude $(BUILD_SHARED_LIBRARY)

 

 

在VMware的ubuntu9.04下编译, NDK r4b的路径在../bld/android-ndk-r4-crystax，使用该ndkbuild

 

root@jernymy-desktop:/mnt/hgfs/workspace/AndroidJni# ../bld/android-ndk-r4-crystax/ndk-build
Compile thumb  : jernymyjni <= /mnt/hgfs/workspace/AndroidJni/jni/com_jni_jernymyjni.c
SharedLibrary  : libjernymyjni.so
Install        : libjernymyjni.so => /mnt/hgfs/workspace/AndroidJni/libs/armeabi
root@jernymy-desktop:/mnt/hgfs/workspace/AndroidJni#

 

接下来编写我们的java的测试代码AndroidJni.java，目前为了方便调试，暂且用System.out输出，
可以通过android在界面上摆放一些button，然后把信息显示到button上，就可以看到效果了
现在可以先通过调试的方式，查看debug的信息。

package com.jni;import android.app.Activity;import android.os.Bundle;public class AndroidJni extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main);System.out.println("hello");jernymyjni cJni = new jernymyjni();System.out.println("--------jernymy test jernymyjni start--------");System.out.println("--------display base type test");System.out.println("--------GetChar('A')--------");char chTmp = cJni.GetChar('A');System.out.println(String.valueOf(chTmp));System.out.println("***************************");System.out.println("--------SetChar('A')--------");int nRtn = cJni.SetChar('A');System.out.println("nRtn:" + String.valueOf(nRtn));System.out.println("***************************");System.out.println("--------GetInt(5, 10)--------");int nSum = cJni.GetInt(5, 10);System.out.println(String.valueOf(nSum));System.out.println("***************************");System.out.println("--------SetInt(10)--------");nRtn = cJni.SetInt(10);System.out.println("nRtn:" + String.valueOf(nRtn));System.out.println("***************************");System.out.println("--------GetStr(/"Jernymy Jni GetStr/")--------");String sStr = cJni.GetStr();System.out.println(sStr);System.out.println("***************************");System.out.println("--------GetStr(/"Jernymy Jni PrcsStr/")--------");sStr = cJni.PrcsStr("Jernymy Jni TestAAA");System.out.println(sStr);System.out.println("***************************");System.out.println("--------SetStr(/"Jernymy Jni SetStr/")--------");nRtn = cJni.SetStr("Java Jni Set");System.out.println("nRtn:" + String.valueOf(nRtn));System.out.println("***************************");System.out.println("------------------------------------------------");System.out.println("--------display array test");System.out.println("--------GetCharArray('A')--------");char[] chAry = cJni.GetCharArray('A');int nIdx;System.out.println("chAry.length:" + String.valueOf(chAry.length));for (nIdx = 0; nIdx < chAry.length; nIdx++){System.out.println(String.valueOf(chAry[nIdx])+" ");}System.out.println("***************************");System.out.println("--------SetCharArray('A')--------");nRtn = cJni.SetCharArray(chAry);System.out.println("nRtn:" + String.valueOf(nRtn));System.out.println("***************************");System.out.println("--------GetIntArray({1, 2, 3}, {4, 5, 6})--------");int[] nAddAry1 = {1, 2, 3};int[] nAddAry2 = {4, 5, 6};int[] nSumAry = cJni.GetIntArray(nAddAry1, nAddAry2);System.out.println("nSumAry.length:" + String.valueOf(nSumAry.length));for (nIdx = 0; nIdx < nSumAry.length; nIdx++){System.out.println(String.valueOf(nSumAry[nIdx])+" ");}System.out.println("***************************");System.out.println("--------SetIntArray({1, 2, 3}--------");nRtn = cJni.SetIntArray(nAddAry1);System.out.println("nRtn:" + String.valueOf(nRtn));System.out.println("***************************");System.out.println("--------GetStrArray(" +"/"Jernymy Java Jni GetStrArray/")--------");String[] sStrAry = cJni.GetStrArray();System.out.println("sStrAry.length:" + String.valueOf(sStrAry.length));for (nIdx = 0; nIdx < sStrAry.length; nIdx++){System.out.println(sStrAry[nIdx]+" ");}System.out.println("***************************");System.out.println("--------PrcsStrArray(" +"/"Jernymy Java Jni PrcsStrArray/")--------");sStrAry = cJni.PrcsStrArray("Jernymy Android JniTest");System.out.println("sStrAry.length:" + String.valueOf(sStrAry.length));for (nIdx = 0; nIdx < sStrAry.length; nIdx++){System.out.println(sStrAry[nIdx]+" ");}System.out.println("***************************");System.out.println("--------SetStrArray({/"Jernymy/"," +" /"Java/", /"Jni/", /"SetStrArray/"})--------");String[] sStrSetAry = {"Jernymy", "Java", "Jni", "SetStrArray"};nRtn = cJni.SetStrArray(sStrSetAry);System.out.println("nRtn:" + String.valueOf(nRtn));System.out.println("***************************");System.out.println("-------------------------------------------------");System.out.println("--------display class test");System.out.println("--------GetClass(0)--------");jernymyjni cComn = cJni.GetClass(0);if (null == cComn){System.out.println("cComn is null");}else{System.out.println( "chChar:" + String.valueOf(cComn.chChar)+" nPuId:" + String.valueOf(cComn.nInt)+" sName:" + cComn.sString);}System.out.println("***************************");System.out.println("--------SetClass({'N', 508, /"Native/"})--------");jernymyjni cComnSet = new jernymyjni();cComnSet.chChar = 'N';cComnSet.nInt = 508;cComnSet.sString = "Native";nRtn = cJni.SetClass(cComnSet);System.out.println("nRtn:" + String.valueOf(nRtn));System.out.println("***************************");System.out.println("--------GetClassArray()--------");jernymyjni[] sStructAry = cJni.GetClassArray();System.out.println("sStructAry:" + String.valueOf(sStructAry.length));for (nIdx = 0; nIdx < sStructAry.length; nIdx++){System.out.println("----index[" + String.valueOf(nIdx) + "]----");if (null == sStructAry[nIdx]){System.out.println("sStructAry is null");}else{System.out.println(""+" chChar: " + String.valueOf(sStructAry[nIdx].chChar)+", nInt: " + String.valueOf(sStructAry[nIdx].nInt)+", sName: " + sStructAry[nIdx].sString);}}System.out.println("***************************");System.out.println("--------SetClassArray(Ncomn[])--------");System.out.println("sStructAry:" + String.valueOf(sStructAry.length));for (nIdx = 0; nIdx < sStructAry.length; nIdx++){System.out.println("index[" + String.valueOf(nIdx)+"] chChar:" + String.valueOf(sStructAry[nIdx].chChar)+" nInt:" + String.valueOf(sStructAry[nIdx].nInt)+" sString:" + sStructAry[nIdx].sString);}nRtn = cJni.SetClassArray(sStructAry);System.out.println("nRtn:" + String.valueOf(nRtn));System.out.println("***************************");System.out.println("--------Jernymy test jernymyjni end --------"); }}

 

好了，基本差不多了，因为俺暂时使用的类型已经足够了，至于其他的在继续研究中，如果错误的地方也请您指出，谢谢啦。
jernymy 20110508
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