NanoMsg框架|C++的相关函数介绍及AndroidNDK的简单使用

# 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.
cmake_minimum_required(VERSION 3.4.1)

#定义程序的目录，后面通过这个来关键编译好的动态库和头文件#我们自己如果要修改目录只改这个地方就可以了set(nanomsgpath "D:/Business/DemoTEST/nanomsgtest/NanoMsg4Android/MakeNanomsgLib/app")
#定义库文件的目录set(nanomsglibpath ${nanomsgpath}/build/intermediates/cmake/debug/obj)

#调用头文件的具体路径include_directories(${nanomsgpath}/src/main/cpp/src)include_directories(${nanomsgpath}/src/main/cpp/src/utils)
#增加我们的动态库add_library(libnanomsg SHARED IMPORTED)
#建立链接set_target_properties(libnanomsg PROPERTIES IMPORTED_LOCATION        "${nanomsglibpath}/${ANDROID_ABI}/libnanomsg.so")
# Creates and names a library, sets it as either STATIC# or SHARED, and provides the relative paths to its source code.# You can define multiple libraries, and CMake builds them for you.# Gradle automatically packages shared libraries with your APK.
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).        native-lib.cpp)
# 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.        native-lib        libnanomsg
        # Links the target library to the log library        # included in the NDK.        ${log-lib})

android {    compileSdkVersion 29    buildToolsVersion "29.0.2"    defaultConfig {        applicationId "dem.vac.androidnanomsg"        minSdkVersion 14        targetSdkVersion 29        versionCode 1        versionName "1.0"        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"        externalNativeBuild {            cmake {                cppFlags "-std=c++11"            }        }    }    buildTypes {        release {            minifyEnabled false            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'        }    }    externalNativeBuild {        cmake {            path "src/main/cpp/CMakeLists.txt"
        }    }
    //加上    sourceSets{        main{            //当前这个目录下的库文件会被调用并且被打包进apk中            jniLibs.srcDirs = ['D:/Business/DemoTEST/nanomsgtest/NanoMsg4Android/MakeNanomsgLib/app/build/intermediates/cmake/debug/obj']        }    }
}

extern "C" JNIEXPORT jstring JNICALLJava_dem_vac_nanomsgdemo_MainActivity_nanomsgtest        (JNIEnv *env, jobject, jstring ipadr_, jstring sendmsg_) {
    char *reschar;    //设置超时地址    int timeo = 5000;
    //获取地址    const char *ipadress = env->GetStringUTFChars(ipadr_, 0);    const char *ipadrpre = "tcp://";
    //拼接地址    int len = strlen(ipadress) + strlen(ipadrpre);    char str[len];    strcpy(str, ipadrpre);    strcat(str, ipadress);
    //获取发送字符串    const char *sendmsg = env->GetStringUTFChars(sendmsg_, 0);
    try {        //创建PAIR的套接字        int pair_socket = nn_socket(AF_SP, NN_PAIR);        if (pair_socket == -1) {            throw "nn_socket failed! error";        }
        //设置超时        int rc;        rc = nn_setsockopt(pair_socket, 0, NN_SNDTIMEO, &timeo, sizeof(timeo));        rc = nn_setsockopt(pair_socket, 0, NN_RCVTIMEO, &timeo, sizeof(timeo));
        //连接服务器        rc = nn_connect(pair_socket, str);        if (rc < 0) {            throw "nn_connect failed! error";        }
        char buf[256] = {0};        //计算长度        int str_len = strlen(sendmsg);        //将sendmsg复制到buf中        memcpy(buf, sendmsg, str_len);
        //发送数据        rc = nn_send(pair_socket, buf, str_len, 0);        if (rc < 0) {            throw "nn_send failed! error";        }
        //接收数据        char buffer[256];        rc = nn_recv(pair_socket, buffer, 256, 0);        if (rc < 0) {            throw "nn_recv failed! error";        }
        char bufrecv[250] = {0};        //将sendmsg复制到buf中        memcpy(bufrecv, buffer, rc);
        reschar = bufrecv;        LOGI("%s\n", reschar);
        memset(buffer, 0, 256);        //关闭套接字        nn_close(pair_socket);    } catch (char *e) {        reschar = e;    }    return env->NewStringUTF(reschar);}

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {        super.onCreate(savedInstanceState)        setContentView(R.layout.activity_main)
        // Example of a call to a native method        sample_text.text = stringFromJNI()
        btnsend.setOnClickListener {            var resstr = ""            try {                sample_text.text = "通讯中"                var ipadr = edtipadr.text.toString()                var sendmsg = "我发个试试";                resstr = nanomsgtest(ipadr, sendmsg)                sample_text.text = resstr            } catch (e: Exception) {                Log.i("ndk", e.message)                sample_text.text = e.message            }
        }    }

    /**     * A native method that is implemented by the 'native-lib' native library,     * which is packaged with this application.     */    external fun stringFromJNI(): String
    external fun nanomsgtest(ipadr: String, sendmsg: String): String

    companion object {
        // Used to load the 'native-lib' library on application startup.        init {            System.loadLibrary("native-lib")        }    }}