C++给Java写程序

柔情只为你懂 2023-10-06 20:00 31阅读 0赞

创建一个Java项目，编码选择utf8  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16]  
编译Java文件生成.h文件  
![在这里插入图片描述][107d848cbf1e4855a73f319d55c256e3.png]  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 1]  
将.h文件拷贝到C++项目中  
![在这里插入图片描述][4bf83f640046437eb0d902e93c44d4fd.png]

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 2]

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 3]  
实现方法  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 4]  
编译生成解决方案，并复制路径E:\\VS2017\\edoyun\\x64\\Release  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 5]

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 6]  
运行输入结果  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 7]  
进阶：实现手动注册一个实现的方法  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 8]  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 9]  
完整代码如下：

package eDoYun;
    
    public class NativeClass {
        
    	public native int nativeAdd(int a, int b);
    
    	public native double nativefAdd(double a, double b);
    
    	public static void main(String[] args) {
        
    		System.loadLibrary("edoyun");// 要生成的C++模块
    
    		NativeClass a = new NativeClass();
    
    		a.nativeAdd(10, 20);
    
    		a.nativefAdd(1.234, 2.345);
    	}
    }

// dllmain.cpp : 定义 DLL 应用程序的入口点。
    #include "pch.h"
    #include"eDoYun_NativeClass.h"
    
    BOOL APIENTRY DllMain( HMODULE hModule,
                           DWORD  ul_reason_for_call,
                           LPVOID lpReserved
                         )
    {
        
        switch (ul_reason_for_call)
        {
        
        case DLL_PROCESS_ATTACH:
        case DLL_THREAD_ATTACH:
        case DLL_THREAD_DETACH:
        case DLL_PROCESS_DETACH:
            break;
        }
        return TRUE;
    }
    
    //实现方式1：通过命名规则绑定
    JNIEXPORT jint JNICALL Java_eDoYun_NativeClass_nativeAdd
    (JNIEnv *, jobject, jint a, jint b) {
        
    	//打印日志和a,b的值
    	printf("%s(%d):%s a=%d b=%d\r\n", __FILE__, __LINE__, __FUNCTION__, a, b);
    	return a + b;
    }
    
    //实现方式2：手动注册方法绑定
    JNIEXPORT jdouble JNICALL nativefAdd
    (JNIEnv *, jobject, jdouble a, jdouble b) {
        
    	//打印日志和a,b的值
    	printf("%s(%d):%s a=%f b=%f\r\n", __FILE__, __LINE__, __FUNCTION__, a, b);
    	return a + b;
    }
    
    
    JNIEXPORT jint JNICALL 
    JNI_OnLoad(JavaVM* vm, void* reserved) {
        
    	jint result = -1;
    	JNIEnv* env = NULL;
    	if (vm->GetEnv((void**)&env, JNI_VERSION_1_1) != JNI_OK) {
        
    		printf("%s(%d):%s\r\n", __FILE__, __LINE__, __FUNCTION__);
    	}
    	jclass clz = env->FindClass("eDoYun/NativeClass");
    	if (clz == NULL) {
        
    		printf("%s(%d):%s\r\n", __FILE__, __LINE__, __FUNCTION__);
    		return -1;
    	}
    
    	JNINativeMethod methods[] = {
        
    		{
        (char*)"nativefAdd",(char*)"(DD)D",(void*)&nativefAdd}//"(DD)D"两个参数都是double返回值也是double
    	};
    
    	//注册
    	result = env->RegisterNatives(clz, methods, sizeof(methods) / sizeof(JNINativeMethod));
    	if (result != 0) {
        
    		printf("%s(%d):%s\r\n", __FILE__, __LINE__, __FUNCTION__);
    		return -1;
    	}
    
    	return JNI_VERSION_1_1;
    }

[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16]: https://img-blog.csdnimg.cn/cf7fc39218124b9681e5667ecca41473.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBA5rGf5bee55uK5b2k,size_20,color_FFFFFF,t_70,g_se,x_16
[107d848cbf1e4855a73f319d55c256e3.png]: https://img-blog.csdnimg.cn/107d848cbf1e4855a73f319d55c256e3.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 1]: https://img-blog.csdnimg.cn/656b7c68a13a46cf9ae21dd91d4a7e00.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBA5rGf5bee55uK5b2k,size_20,color_FFFFFF,t_70,g_se,x_16
[4bf83f640046437eb0d902e93c44d4fd.png]: https://img-blog.csdnimg.cn/4bf83f640046437eb0d902e93c44d4fd.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 2]: https://img-blog.csdnimg.cn/6866b635a0044608a32729cea5a4398a.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBA5rGf5bee55uK5b2k,size_20,color_FFFFFF,t_70,g_se,x_16
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 3]: https://img-blog.csdnimg.cn/4aad0ff7079b4c3f87354dba2a7e67ea.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBA5rGf5bee55uK5b2k,size_20,color_FFFFFF,t_70,g_se,x_16
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 4]: https://img-blog.csdnimg.cn/c4832a933b0e4e3490270d388cce6d12.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBA5rGf5bee55uK5b2k,size_20,color_FFFFFF,t_70,g_se,x_16
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 5]: https://img-blog.csdnimg.cn/6cffce4c87514444ab414473b2ba1479.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBA5rGf5bee55uK5b2k,size_20,color_FFFFFF,t_70,g_se,x_16
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 6]: https://img-blog.csdnimg.cn/f979d21eede642dc90a9384a46508912.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBA5rGf5bee55uK5b2k,size_20,color_FFFFFF,t_70,g_se,x_16
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 7]: https://img-blog.csdnimg.cn/077b8690eec04687827e297877148142.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBA5rGf5bee55uK5b2k,size_20,color_FFFFFF,t_70,g_se,x_16
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 8]: https://img-blog.csdnimg.cn/3e0e538517da40d2bd621b6cfc0742d1.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBA5rGf5bee55uK5b2k,size_20,color_FFFFFF,t_70,g_se,x_16
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5rGf5bee55uK5b2k_size_20_color_FFFFFF_t_70_g_se_x_16 9]: https://img-blog.csdnimg.cn/5ee123b4501c430a8107aa4da4759b1b.png?x-oss-process=image/watermark,type_ZHJvaWRzYW5zZmFsbGJhY2s,shadow_50,text_Q1NETiBA5rGf5bee55uK5b2k,size_20,color_FFFFFF,t_70,g_se,x_16