1.CMakeList.txt 配置
add_library( # Sets the name of the library.
native-lib
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
src/main/cpp/native-lib.cpp
)
add_library( # Sets the name of the library.
Hello
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
src/main/cpp/Hello.c
)
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log )
target_link_libraries( # Specifies the target library.
native-lib
# Links the target library to the log library
# included in the NDK.
${log-lib} )
target_link_libraries( # Specifies the target library.
Hello
# Links the target library to the log library
# included in the NDK.
${log-lib} )
2.gradle 添加依赖
android {
defaultConfig{
externalNativeBuild {
cmake {
cppFlags "-frtti -fexceptions"
}
ndk {
abiFilters 'armeabi', 'armeabi-v7a', 'arm64-v8a',"x86" //添加cpu平台
}
}
}
externalNativeBuild {
cmake {
path "CMakeLists.txt"
}
}
}
3.新建一个类 JNI.java 添加本地方法
public class JNI {
static {
System.loadLibrary("Hello");
}
public native String getNameFromJni();
public native int add(int x, int y);
public native String connect(String str);
public native String md5FromJni(String str);
}
4.在cpp 下创建c/c++文件 Hello.c
#include <jni.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "MD5Utils.h"
#include "MD5Utils.c"
#include <android/log.h>
#define LOG_TAG "Hello"
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
JNIEXPORT jstring JNICALL
Java_com_lixinxin_jnidemo1_jni_JNI_getNameFromJni(JNIEnv *env, jobject instance) {
char *returnValue = "Hello";
return (*env)->NewStringUTF(env, returnValue);
}
JNIEXPORT jint JNICALL
Java_com_lixinxin_jnidemo1_jni_JNI_add(JNIEnv *env, jobject instance, jint x, jint y) {
int value = x + y;
return value;
}
JNIEXPORT jstring JNICALL
Java_com_lixinxin_jnidemo1_jni_JNI_connect(JNIEnv *env, jobject instance, jstring str_) {
const char *str = (*env)->GetStringUTFChars(env, str_, 0);
char *value = strcat(str, " jni string");
return (*env)->NewStringUTF(env, value);
}
JNIEXPORT jstring JNICALL
Java_com_lixinxin_jnidemo1_jni_JNI_md5FromJni(JNIEnv *env, jobject instance, jstring str_) {
const char *str = (*env)->GetStringUTFChars(env, str_, 0);
MD5_CTX md5;
MD5Init(&md5);
unsigned char decrypt[16];
MD5Update(&md5, str, strlen(str));
MD5Final(&md5, decrypt);
unsigned char hexstr[32];
for (int i = 0; i < 16; i++) {
sprintf(&hexstr[i * 2], "%02x", decrypt[i]);
}
LOGE("name=%s", (char *) hexstr);
return (*env)->NewStringUTF(env, (char *) hexstr);
}
5.调用
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView tv = (TextView) findViewById(R.id.sample_text);
JNI jni = new JNI();
tv.setText(jni.md5FromJni("111111"));
}
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