公司网站建设介绍,灵感素材库,搜关键词可以搜到的网站怎么做,电商税收新政策2021前些天发现了一个蛮有意思的人工智能学习网站,8个字形容一下通俗易懂#xff0c;风趣幽默#xff0c;感觉非常有意思,忍不住分享一下给大家。 #x1f449;点击跳转到教程 第一步首先配置Android studio的NDK开发环境#xff0c;首先在Android studio中下载NDK… 前些天发现了一个蛮有意思的人工智能学习网站,8个字形容一下通俗易懂风趣幽默感觉非常有意思,忍不住分享一下给大家。 点击跳转到教程 第一步首先配置Android studio的NDK开发环境首先在Android studio中下载NDK包 第二步在local.properties文件中配置对应的NDK路径 第三歩在app目录下的build.gradle文件中的android{}闭包中指定CMakeLists.txt路径
// 在android节点下// 指定CMakeLists.txt路径externalNativeBuild {cmake {// 在该文件种设置所要编写的c源码位置以及编译后so文件的名字path CMakeLists.txt}}在defaultConfig闭包下配置
// 增加cmake控制属性externalNativeBuild {cmake {// 指定编译架构abiFilters arm64-v8a, armeabi-v7a, x86, x86_64}}在app目录下指定CmakeLists.txt文件根据注释进行相应添加
# CMakeLists.txt
# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html# Sets the minimum version of CMake required to build the native library.
#CMakeLists.txt
cmake_minimum_required(VERSION 3.4.1)# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
add_library(# 设置so文件名称.Hello# 设置这个so文件为共享.SHARED# Provides a relative path to your source file(s).src/main/jni/Hello.c)
add_library(# 设置so文件名称.Test# 设置这个so文件为共享.SHARED# Provides a relative path to your source file(s).src/main/jni/Test.c)
add_library(# 设置so文件名称.CCallJava# 设置这个so文件为共享.SHARED# Provides a relative path to your source file(s).src/main/jni/CCallJava.c)# 添加 log 库的链接
target_link_libraries(CCallJava log)
target_link_libraries(Test log)# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
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 )# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
target_link_libraries( # Specifies the target library.# 制定目标库.Hello# Links the target library to the log library# included in the NDK.${log-lib} )第四步首先进行Java代码C代码的操作 1.JNI2.java代码如下
/*** Author: ly* Date: 2023/8/6* Description: java调C代码*/
public class JNI2 {static {System.loadLibrary(Test); //加载动态链接库}/*** 让C代码做加法运算,把结果返回* 场景大量运算编解码之类的需要性能很高的情况下可以用C代码** param x* param y* return*/public native int add(int x, int y);/*** 从java传入字符串C代码进行拼接** param s I am from java* return I am from java and I am from c*/public native String sayHello(String s);/*** 让C代码给每个元素都加上10** param intArray* return*/public native int[] increaseArrayEles(int[] intArray);/*** 应用检查密码是否正确如果正确返回200否则返回400** param pwd* return*/public native int checkPwd(String pwd);
}2.根据命令行javah JNI2的全类名生成Test.c对应的C代码头文件com_example_jniproject_JNI2.h
/* DO NOT EDIT THIS FILE - it is machine generated */
#include jni.h
/* Header for class com_example_jniproject_JNI2 */#ifndef _Included_com_example_jniproject_JNI2
#define _Included_com_example_jniproject_JNI2
#ifdef __cplusplus
extern C {
#endif
/** Class: com_example_jniproject_JNI2* Method: add* Signature: (II)I*/
JNIEXPORT jint JNICALL Java_com_example_jniproject_JNI2_add(JNIEnv *, jobject, jint, jint);/** Class: com_example_jniproject_JNI2* Method: sayHello* Signature: (Ljava/lang/String;)Ljava/lang/String;*/
JNIEXPORT jstring JNICALL Java_com_example_jniproject_JNI2_sayHello(JNIEnv *, jobject, jstring);/** Class: com_example_jniproject_JNI2* Method: increaseArrayEles* Signature: ([I)[I*/
JNIEXPORT jintArray JNICALL Java_com_example_jniproject_JNI2_increaseArrayEles(JNIEnv *, jobject, jintArray);/** Class: com_example_jniproject_JNI2* Method: checkPwd* Signature: (Ljava/lang/String;)I*/
JNIEXPORT jint JNICALL Java_com_example_jniproject_JNI2_checkPwd(JNIEnv *, jobject, jstring);#ifdef __cplusplus
}
#endif
#endif3.根据jni协议去写对应的c代码创建Test.c文件代码如下
//
// Created by DELL on 2023/8/6.
//
#include com_example_jniproject_JNI2.h
#include string.h
#include stdlib.h#include android/log.h#define TAG luyu
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG,TAG ,__VA_ARGS__) // 定义LOGD类型
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO,TAG ,__VA_ARGS__) // 定义LOGI类型
#define LOGW(...) __android_log_print(ANDROID_LOG_WARN,TAG ,__VA_ARGS__) // 定义LOGW类型
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR,TAG ,__VA_ARGS__) // 定义LOGE类型
#define LOGF(...) __android_log_print(ANDROID_LOG_FATAL,TAG ,__VA_ARGS__) // 定义LOGF类型JNIEXPORT char *JNICALL Java_com_example_MyClass_myMethod(JNIEnv *env, jobject obj, jstring jstr) {const char *cstr (*env)-GetStringUTFChars(env, jstr, NULL);// 使用 cstr 进行操作并获取结果假设结果为 result(*env)-ReleaseStringUTFChars(env, jstr, cstr);char *result (char *) malloc(strlen(cstr) 1);strcpy(result, cstr);return result;
}/*** jint:返回值* Java_全类名_方法名* JNIEnv *env*/
jint Java_com_example_jniproject_JNI2_add(JNIEnv *env, jobject jobj, jint ji, jint jj) {int result ji jj;return result;
};/*** 从java传入字符串C代码进行拼接** param s I am from java* return I am from java and I am from c
*/jstring Java_com_example_jniproject_JNI2_sayHello(JNIEnv *env, jobject jobj, jstring jstring1) {char *fromJava Java_com_example_MyClass_myMethod(env, jobj, jstring1);char *fromC and I am from C;//拼接函数拼接后得到的结果放到第一个参数里面strcat(fromJava, fromC);//把拼接的结果放在第一个参数里面//jstring (*NewStringUTF)(JNIEnv*, const char*);LOGE(fromJava%s\n, fromJava);return (*env)-NewStringUTF(env, fromJava);
};/*** 给每个元素加10* 场景图片处理颜色矩阵(就是数组)进行数组的处理*/
jintArray Java_com_example_jniproject_JNI2_increaseArrayEles(JNIEnv *env, jobject jobj, jintArray jintArray1) {//1.得到数组的长度//jsize (*GetArrayLength)(JNIEnv*, jarray);jsize size (*env)-GetArrayLength(env, jintArray1);//2.得到数组的元素// jint* (*GetIntArrayElements)(JNIEnv*, jintArray, jboolean*);jint *intArray (*env)-GetIntArrayElements(env, jintArray1,JNI_FALSE);//这里传0 false表示 在同一份内存操作不开辟新的内存//3.遍历数组给每个元素加10int i;for (i 0; i size; i) {*(intArray i) 10;}// 4. 同步修改到 Java 层(*env)-ReleaseIntArrayElements(env, jintArray1, intArray, 0);//4.返回结果return jintArray1;
};/*** 应用检查密码是否正确如果正确返回200否则返回400*/
jint Java_com_example_jniproject_JNI2_checkPwd(JNIEnv *env, jobject jobj, jstring jstring1) {//假设服务器的密码是123456char *origin 123456;char *fromUser Java_com_example_MyClass_myMethod(env, jobj, jstring1);//函数比较字符串是否相同int code strcmp(origin, fromUser);LOGE(code%d\n, code);if (code 0) {return 200;} else {return 400;}
};第五步C代码调用Java代码首先创建JNI3.java
/*** Author: ly* Date: 2023/8/6* Description: C代码调用Java代码*/
public class JNI3 {static {System.loadLibrary(CCallJava); //加载动态链接库}//当执行这个方法的时候让C代码调用//public int add(int x, int y)public native void callbackAdd();/*** 当执行这个方法的时候让C代码调用* public void helloFromJava()*/public native void callbackHelloFromJava();/*** 当执行这个方法的时候让C代码调用* public void printString(String s)*/public native void callbackPrintString();/*** 当执行这个方法的时候让C代码调用* public static void sayHello(String s)*/public native void callbackSayHello();public int add(int x, int y) {Log.e(TAG, add() x x y y);return x y;}public void helloFromJava() {Log.e(TAG, helloFromJava);}public void printString(String s) {Log.e(TAG, C中输入的 s);}public static void sayHello(String s) {Log.e(TAG, 我是java代码中的JNI .java中的sayHello(String s)静态方法,我被C调用了 s);}
}2.根据命令行javah JNI3全类名生成CCallJava.c对应的头文件 com_example_jniproject_JNI3.h
/* DO NOT EDIT THIS FILE - it is machine generated */
#include jni.h
/* Header for class com_example_jniproject_JNI3 */#ifndef _Included_com_example_jniproject_JNI3
#define _Included_com_example_jniproject_JNI3
#ifdef __cplusplus
extern C {
#endif
/** Class: com_example_jniproject_JNI3* Method: callbackAdd* Signature: ()V*/
JNIEXPORT void JNICALL Java_com_example_jniproject_JNI3_callbackAdd(JNIEnv *, jobject);/** Class: com_example_jniproject_JNI3* Method: callbackHelloFromJava* Signature: ()V*/
JNIEXPORT void JNICALL Java_com_example_jniproject_JNI3_callbackHelloFromJava(JNIEnv *, jobject);/** Class: com_example_jniproject_JNI3* Method: callbackPrintString* Signature: ()V*/
JNIEXPORT void JNICALL Java_com_example_jniproject_JNI3_callbackPrintString(JNIEnv *, jobject);/** Class: com_example_jniproject_JNI3* Method: callbackSayHello* Signature: ()V*/
JNIEXPORT void JNICALL Java_com_example_jniproject_JNI3_callbackSayHello(JNIEnv *, jobject);#ifdef __cplusplus
}
#endif
#endif
3.对应的CCallJava.c文件中的代码如下
//
// Created by DELL on 2023/8/6.
//
#include com_example_jniproject_JNI3.h
#include stdlib.h
#include stdio.h#include android/log.h#define TAG luyu
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG,TAG ,__VA_ARGS__) // 定义LOGD类型
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO,TAG ,__VA_ARGS__) // 定义LOGI类型
#define LOGW(...) __android_log_print(ANDROID_LOG_WARN,TAG ,__VA_ARGS__) // 定义LOGW类型
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR,TAG ,__VA_ARGS__) // 定义LOGE类型
#define LOGF(...) __android_log_print(ANDROID_LOG_FATAL,TAG ,__VA_ARGS__) // 定义LOGF类型/*** 让C代码调用Java中JNI类的public int add(int x ,int y)*/
JNIEXPORT void Java_com_example_jniproject_JNI3_callbackAdd(JNIEnv *env, jobject jobj) {//1.得到字节码//jclass (*FindClass)(JNIEnv*, const char*);jclass jclazz (*env)-FindClass(env, com/example/jniproject/JNI3);//2.得到方法//jmethodID (*GetMethodID)(JNIEnv*, jclass, const char*, const char*);//最后一个参数是方法签名jmethodID jmethodId (*env)-GetMethodID(env, jclazz, add, (II)I);//3.实例化该类jobject jobject1 (*env)-AllocObject(env, jclazz);//4.调用方法//jint (*CallIntMethod)(JNIEnv*, jobject, jmethodID, ...);jint value (*env)-CallIntMethod(env, jobject1, jmethodId, 99, 1);//成功调用LOGE(value%d\n, value);
};/**** 让C代码调用* public void helloFromJava()*/
JNIEXPORT void JNICALL Java_com_example_jniproject_JNI3_callbackHelloFromJava(JNIEnv *env, jobject jobj) {//1.得到字节码//jclass (*FindClass)(JNIEnv*, const char*);jclass jclazz (*env)-FindClass(env, com/example/jniproject/JNI3);//2.得到方法//jmethodID (*GetMethodID)(JNIEnv*, jclass, const char*, const char*);//最后一个参数是方法签名jmethodID jmethodIds (*env)-GetMethodID(env, jclazz, helloFromJava, ()V);//3.实例化该类jobject jobject1 (*env)-AllocObject(env, jclazz);//4.调用方法//jint (*CallIntMethod)(JNIEnv*, jobject, jmethodID, ...);(*env)-CallVoidMethod(env, jobject1, jmethodIds);
};/**** 让C代码调用* public void printString(String s)**/
JNIEXPORT void JNICALL Java_com_example_jniproject_JNI3_callbackPrintString(JNIEnv *env, jobject jobj) {//1.得到字节码//jclass (*FindClass)(JNIEnv*, const char*);jclass jclazz (*env)-FindClass(env, com/example/jniproject/JNI3);//2.得到方法//jmethodID (*GetMethodID)(JNIEnv*, jclass, const char*, const char*);//最后一个参数是方法签名jmethodID jmethodIds (*env)-GetMethodID(env, jclazz, printString, (Ljava/lang/String;)V);//3.实例化该类jobject jobject1 (*env)-AllocObject(env, jclazz);//4.调用方法//jint (*CallIntMethod)(JNIEnv*, jobject, jmethodID, ...);// jstring (*NewStringUTF)(JNIEnv*, const char*);jstring jst (**env).NewStringUTF(env, I am Android!);(*env)-CallVoidMethod(env, jobject1, jmethodIds, jst);
};/*** 让C代码调用* public static void sayHello(String s)**/
JNIEXPORT void JNICALL Java_com_example_jniproject_JNI3_callbackSayHello(JNIEnv *env, jobject jobj){//1.得到字节码//jclass (*FindClass)(JNIEnv*, const char*);jclass jclazz (*env)-FindClass(env, com/example/jniproject/JNI3);//2.得到方法// jmethodID (*GetStaticMethodID)(JNIEnv*, jclass, const char*, const char*);//最后一个参数是方法签名jmethodID jmethodIds (*env)-GetStaticMethodID(env, jclazz, sayHello, (Ljava/lang/String;)V);jstring jst (**env).NewStringUTF(env, I am Android!);(*env)-CallStaticVoidMethod(env,jclazz,jmethodIds,jst);
};
之后在MainActivity中调用对应的方法即可
public class MainActivity extends AppCompatActivity {private JNI2 jin2;private static final String TAG MainActivity;private JNI3 mJNI3;Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);jin2 new JNI2();mJNI3 new JNI3();}/******以下是Java代码调用C*****/public void checkPwd(View view) {int result jin2.checkPwd(12345678);Log.i(TAG, result result);}public void increaseArrayEles(View view) {int array[] {1, 2, 3, 4};jin2.increaseArrayEles(array);for (int i 0; i array.length; i) {Log.i(TAG, result[ i ]: array[i]);}}public void sayHello(View view) {String result jin2.sayHello(I am from java);Log.i(TAG, result result);}public void add(View view) {int result jin2.add(99, 1);Log.i(TAG, result result);}/******以下是C调Java代码*****/public void callbackAdd(View view) {mJNI3.callbackAdd();}public void callbackHelloFromJava(View view) {mJNI3.callbackHelloFromJava();}public void callbackPrintString(View view) {mJNI3.callbackPrintString();}public void callbackSayHello(View view) {mJNI3.callbackSayHello();}
}点击按钮便可输出对应的日志表示调用成功。
