public void onCreate(Bundle savedInstanceState)
??? {
??????? super.onCreate(savedInstanceState);
??????? Button btn = new Button(this);
??????? btn.setText("測試ndk");
??????? btn.setOnClickListener(new ButtonOnClickListener());
??????? setContentView(btn);
??????? Toast.makeText(getApplicationContext(), PATH, Toast.LENGTH_LONG).show();
??? }
????
??? public final class ButtonOnClickListener implements OnClickListener{
??? ?
??@Override
??public void onClick(View arg0) {
???// TODO Auto-generated method stub
???byte[] data = "zhanghongliu".getBytes();
???FileInputStream fis = null;
???FileOutputStream fos = null;
???int i = 0;
???????? for(i=1;i<=200000;i++){
????try {
?????fis = new FileInputStream(RESOURCEPATH);
?????int size = fis.available();
?????data = new byte[size];
?????fis.read(data, 0, size);
?????String result = FileJNILib.videoCrypt(data,ENCRYPTPATH);
?????Toast.makeText(getApplicationContext(), result, Toast.LENGTH_LONG).show();
?????
????????? ?data = FileJNILib.videoDerypt(ENCRYPTPATH);
????????? ?fos = new FileOutputStream(DECRYPTPATH);
????????? ?fos.write(data);
????} catch (FileNotFoundException e) {
?????// TODO Auto-generated catch block
?????e.printStackTrace();
????} catch (IOException e) {
?????// TODO Auto-generated catch block
?????e.printStackTrace();
????}finally{
?????try {
??????if(null != fis){
???????fis.close();
??????}
??????if(null != fos){
???????fos.close();
??????}
??????data = null;
?????} catch (IOException e) {
??????// TODO Auto-generated catch block
??????e.printStackTrace();
?????}
????}
???????? ?Log.i("count", i+"");
???????? ?//data = null;
???????? }
???????? //Toast.makeText(getApplicationContext(), new String(data), Toast.LENGTH_LONG).show();
??? ??//show();
??}
??
??public void show(){
???File newfile = new File(PATH);
???????? FileInputStream inStream = null;
???try {
????inStream = new FileInputStream(newfile);
???} catch (FileNotFoundException e) {
????// TODO Auto-generated catch block
????//e.printStackTrace();
???}
???????? String content = FileUtil.readInStream(inStream);
???????? Log.i("FileText", content);
???????? Toast.makeText(getApplicationContext(), content, Toast.LENGTH_LONG).show();
??}
??? ?
??? }

?

public static String readInStream(FileInputStream inStream){
??try {
???ByteArrayOutputStream outStream = new ByteArrayOutputStream();
???byte[] buffer = new byte[1024];
???int length = -1;
???while((length = inStream.read(buffer)) != -1 ){
????outStream.write(buffer, 0, length);
???}
???outStream.close();
???inStream.close();
???return outStream.toString();
??} catch (IOException e) {
???Log.i(TAG, e.getMessage());
??}
??return null;
?}

?

public class FileJNILib {
?
?static {
??????? System.loadLibrary("filejni");
??? }
??? public static native String videoCrypt(byte[] content, String dest_file);
??? public static native byte[] videoDerypt(String dest_file);

??? public static native String videoDerypt(String dest_file, ByteArrayOutputStream outputstream);
????
}

?

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/stat.h>

#include <jni.h> //jni的主要頭文件

#include <android/log.h>
#define LOG_TAG "JNI"
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
/* Header for class com_test_jni_FileJNILib */

/*
?* Class:???? com_test_jni_FileJNILib
?* Method:??? videoCrypt
?* Signature: ([BLjava/lang/String;)V
?*/
JNIEXPORT jstring JNICALL videoCrypt
? (JNIEnv * env, jclass thiz, jbyteArray content, jstring dest_file){
??//env->GetStringUTFChars(source,NULL);

??const char *path = (*env)->GetStringUTFChars(env, dest_file, NULL);
??LOGI(path);

??FILE *fp = fopen(path,"wb");
??if(fp==NULL){
???LOGI("fopen error");
???(*env)->ReleaseStringUTFChars(env,dest_file, path);
???return (*env)->NewStringUTF(env, "fopen error");
??}
??char *data = (*env)->GetByteArrayElements(env,content, 0);
??int size = (*env)->GetArrayLength(env,content);
??//int iLen = sizeof(data);//C語言中判斷數據類型或者表達式長度符
??LOGI("file size is %d", size);

??crypt(data,size);

??/******文件寫入方法***********/
??//fputc('c',fp);
??//fputs(data,fp);
??fwrite(data,size,1,fp);
??//fprintf(fp,"%s",data);
??/*****************/

??fclose(fp);
??(*env)->ReleaseByteArrayElements(env,content,data,0);
??(*env)->ReleaseStringUTFChars(env,dest_file, path);
??LOGI("execute complete");
??return (*env)->NewStringUTF(env, "encrypt successful");
}

/*
?* Class:???? com_test_jni_FileJNILib
?* Method:??? videoDerypt
?* Signature: (Ljava/lang/String;)[B
?*/
JNIEXPORT jbyteArray JNICALL videoDerypt
? (JNIEnv * env, jclass thiz, jstring dest_file){
???const char *path = (*env)->GetStringUTFChars(env, dest_file, NULL);
???LOGI(path);

???/*****得到文件長度*******/
???int size;
???struct stat? tFileStat;
???if( stat(path, &tFileStat ) )
???{
????LOGI("file not found error");
????(*env)->ReleaseStringUTFChars(env,dest_file, path);
????return NULL;
???}
???size=tFileStat.st_size;
???LOGI("file size is %d",size);//報錯 int
???/************/

???/*****分配內存*******/
???char *temp = NULL;
???temp=(char*)malloc(size);
???if(temp == NULL)
???{
????LOGI("malloc error");
????(*env)->ReleaseStringUTFChars(env,dest_file, path);
????return NULL;
???}
???// memset(temp,0x00,size*sizeof(char)+1);//初始化內存
???/************/

???FILE *fp = fopen(path,"rb");
???if(fp==NULL){
????LOGI("fopen error");
????(*env)->ReleaseStringUTFChars(env,dest_file, path);
????free(temp);//釋放內存
????temp=NULL;
????return NULL;
???}

???/******文件讀方法***********/
???//fgetc(fp);
???//fgets(temp,100,fp);
???fread(temp,size,1,fp);
???//fscanf(fp,"%s",temp);
???/*****************/

???fclose(fp);

???crypt(temp,size);

???jbyteArray jarrRV =(*env)->NewByteArray(env,size);
???jbyte *jby =(*env)->GetByteArrayElements(env,jarrRV, 0);
???memcpy(jby, temp, size);//復制數據
???(*env)->SetByteArrayRegion(env,jarrRV, 0,size, jby);//將Jbyte 轉換為jbarray數組
???(*env)->ReleaseByteArrayElements(env,jarrRV,jby,0);//釋放jby數組* 解決長時間運行退出問題 內部引用超過指定數量
???//(*env)->DeleteLocalRef(env,jarrRV);//影響程序
???//(*env)->DeleteLocalRef(env,temp);//不對? 一般用malloc申請內存，free釋放
???free(temp);
???temp=NULL;
???(*env)->ReleaseStringUTFChars(env,dest_file, path);
???LOGI("execute complete");
???return jarrRV;
}

void crypt(char *data, int size){
?int i;
?char sPwd[]="************************";
??? int pwdLen = sizeof(sPwd);
??? //LOGI("dongao.com mobile_encrypt %d",pwdLen);
?int count=0;
?for(i=0; i<size; i++)
?{
??????????? if(count >= pwdLen) count = 0;
???data[i]=data[i]^sPwd[count++];
???//LOGI("%c",sPwd[count >= 10 ?count=0:count++]);
?}
}

/*
?* Class:???? com_test_jni_FileJNILib
?* Method:??? videoDerypt
?* Signature: (Ljava/lang/String;Ljava/io/ByteArrayOutputStream;)V
?*/
JNIEXPORT jstring JNICALL videoDerypt2ByteArray
? (JNIEnv * env, jclass thiz, jstring dest_file, jobject outputstream){
?return NULL;
}

static const JNINativeMethod gMethods[] = { //定義批量注冊的數組，是注冊的關鍵部分
{"videoCrypt", "([BLjava/lang/String;)Ljava/lang/String;", (void*)videoCrypt} ,// func2是在java中聲明的native函數名，"()V"是函數的簽名，可以通過javah獲取。
{"videoDerypt", "(Ljava/lang/String;)[B", (void*)videoDerypt},
{"videoDerypt", "(Ljava/lang/String;Ljava/io/ByteArrayOutputStream;)Ljava/lang/String;", (void*)videoDerypt2ByteArray}
};

JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void *reserved) //這是JNI_OnLoad的聲明，必須按照這樣的方式聲明

{

JNIEnv* env = NULL; //注冊時在JNIEnv中實現的，所以必須首先獲取它

jint result = -1;

if((*vm)->GetEnv(vm, (void**)&env, JNI_VERSION_1_4) != JNI_OK) //從JavaVM獲取JNIEnv，一般使用1.4的版本

? return -1;

jclass clazz;

static const char* const kClassName="com/test/jni/FileJNILib";

?

clazz = (*env)->FindClass(env, kClassName); //這里可以找到要注冊的類，前提是這個類已經加載到java虛擬機中。 這里說明，動態庫和有native方法的類之間，沒有任何對應關系。

?

if(clazz == NULL)

{

?LOGI("cannot get class:%s\n", kClassName);

? return -1;

}

if((*env)->RegisterNatives(env, clazz,gMethods, sizeof(gMethods)/sizeof(gMethods[0]))!= JNI_OK) //這里就是關鍵了，把本地函數和一個java類方法關聯起來。不管之前是否關聯過，一律把之前的替換掉！

{

?LOGI("register native method failed!\n");

? return -1;

}

?

return JNI_VERSION_1_4; //這里很重要，必須返回版本，否則加載會失敗。

}

原文?http://blog.csdn.net/zhanghongliu1122/article/details/9411921

轉載于:https://www.cnblogs.com/langtianya/p/3723840.html

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