本文主要是介绍二、JNI生成so之c与java方法互调，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
C与Java方法互调
1 编写工具类
public class NdkJniUtils {static {System.loadLibrary("testJni"); //defaultConfig.ndk.moduleName}public native String getStringC();//调用c的加密public native String encrypt(String content);//调用c的解密public native String decrypt(String content);//调用c的无返回值解密public native void voidDecrypt(String content);//调用c的md5加密public native String md5Encrypt(String content);public native String getNativeMethod(String content,int i,boolean b,double d,float f,char c);//c调用java的静态方法加密public static String encrypt(String key,String platinText)throws Exception{Log.e("encrypt",platinText);return platinText+"111";}//c调用java的静态方法解密public static String decrypt(String key,String cryptedText)throws Exception{Log.e("decrypt",cryptedText);return cryptedText.substring(0,cryptedText.length()-3);}//c调用java的实例方法解密public void voidDecrypt(String key,String cryptedText)throws Exception{Log.e("voidDecrypt",cryptedText);}
}
2 生成.h文件，创建一个.c文件.c内容：
#include "com_ywj_demojni_NdkJniUtils.h"
#include <stdlib.h>
const char *DES_KEY = "12345678912345678912345678912345";
JNIEXPORT jstring JNICALL Java_com_ywj_demojni_NdkJniUtils_getStringC(JNIEnv *env, jobject obj){return (*env)->NewStringUTF(env,"我来自c");
}
JNIEXPORT jstring JNICALL Java_com_ywj_demojni_NdkJniUtils_encrypt(JNIEnv *env, jclass jclass1, jstring jstr)
{if (jstr == NULL) {return NULL;}jstring key;jstring result;jclass AESencrypt;jmethodID mid;AESencrypt = (*env)->FindClass(env, "com/ywj/demojni/NdkJniUtils");if (NULL == AESencrypt) {return NULL;}mid = (*env)->GetStaticMethodID(env, AESencrypt, "encrypt","(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;");if (NULL == mid) {(*env)->DeleteLocalRef(env, AESencrypt);return NULL;}key = (*env)->NewStringUTF(env, DES_KEY);result = (*env)->CallStaticObjectMethod(env, AESencrypt, mid, key, jstr);(*env)->DeleteLocalRef(env, AESencrypt);(*env)->DeleteLocalRef(env, key);return result;
}JNIEXPORT jstring JNICALL Java_com_ywj_demojni_NdkJniUtils_decrypt(JNIEnv *env, jclass jclass1, jstring jstr)
{if (jstr == NULL) {return NULL;}jstring key;jstring result;jclass AESencrypt;jmethodID mid;AESencrypt = (*env)->FindClass(env, "com/ywj/demojni/NdkJniUtils");if (NULL == AESencrypt) {return NULL;}mid = (*env)->GetStaticMethodID(env, AESencrypt, "decrypt","(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;");if (NULL == mid) {(*env)->DeleteLocalRef(env, AESencrypt);return NULL;}key = (*env)->NewStringUTF(env, DES_KEY);result = (*env)->CallStaticObjectMethod(env, AESencrypt, mid, key, jstr);(*env)->DeleteLocalRef(env, AESencrypt);(*env)->DeleteLocalRef(env, key);return result;
}
3 Activity中使用mTextView = (TextView) this.findViewById(R.id.test);String str="123456";NdkJniUtils util = new NdkJniUtils();String encrypt=util.encrypt(str);String decrypt=util.decrypt(encrypt);mTextView.setText(util.getStringC()+"\n"+"原字符串:"+str+"\n"+"加密 后:"+encrypt+"\n"+"解密 后:"+decrypt);
4 编译运行即可这篇关于二、JNI生成so之c与java方法互调的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
