PC和Android(安卓)adb通信

前几天研究截屏，查看ddmlib源码，发现adb通信是通过socket完成的，通过流传输可以提高效率。

adb 命令：adb forward,可以创建socket,官方解释如下

Forwarding Ports

You can use the forwardcommand to set up arbitrary port forwarding — forwarding of requests ona specific host port to a different port on an emulator/deviceinstance. Here's how you would set up forwarding of host port 6100 toemulator/device port 7100:

adb forward tcp:6100 tcp:7100

我的理解就是pc机端口127.0.0.1:6100映射到Android设备的7100端口。

模型图

我以PC为客户端，Android设备为服务端写个例子。

PC端口为1352，Android设备端口为2235,这是我的电话号码前几位。

Android服务端：

写一个监听2235端口的服务

首先添加权限

Java代码

服务端监听连接，连接后发一个ack "you connect me"给pc客户端,等待用户发过来的消息。

   protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_test);        try {            mServerSocket = new ServerSocket(2235);        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }        protected void onDestroy()    {        bRun = false;    }        public void onClick(View vt)    {        Log.i(TAG, "start listen socket accept");        acceptThread();    }        private void acceptThread(){        if (bRun)            return;                bRun = true;        Runnable r = new Runnable() {                        @Override            public void run() {                                // TODO Auto-generated method stub                while(bRun) {                    Socket sock = accept();                    if (sock != null) {                        Log.i(TAG, "sock is not null ptr:" + sock.getPort() + " is connect");                        new SocketChild(sock).start();                                            } else {                        //Log.i(TAG, "sock is null");                    }                    try {                        Thread.sleep(100);                    } catch (InterruptedException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }            }        };        new Thread(r).start();    }        private Socket accept() {        Socket sock = null;        try {            sock = mServerSocket.accept();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        return sock;    }    public class SocketChild extends Thread{        private Socket mSocket;        public  SocketChild(Socket sock) {            // TODO Auto-generated constructor stub            mSocket = sock;            ack("you connect me");                }                private void ack(String ack) {            try {                mSocket.getOutputStream().write(ack.getBytes());            } catch (IOException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }                @Override        public void run() {            while(bRun) {                try {                    sleep(100);                    read();                } catch (InterruptedException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                } catch (IOException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }            try {                mSocket.close();            } catch (IOException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }                private void read() throws IOException {            InputStream input;            byte [] buffer = new byte[1024];            input = mSocket.getInputStream();            int len = input.read(buffer, 0, 1024);            Log.i(TAG, new String(buffer).substring(0, len));        }    }

PC端

准备条件：

1、配置好adb环境

2、使用TCP调试工具

建立连接，在PC端CMD输入：adb forward tcp:1352 tcp:2235

代开TCP调试工具，连接1352端口，发送"hello world",得到Android设备回传的"you connect me".

再看Android服务端

我这边偷懒，直接用Locat打印Android服务端显示

这就完成了一个完整的连接，发送，应答的过程。

通过这个命令可以引申很多东西，如果你想使用screencap -p持续生成图像，再使用adb pull导出来，一次过程也得几秒，使用这种流的方式就高效多了，可以参考/system/core/adb/framebuffer_service.c的方式把图像数据导出来，这样就可以保证图像的流畅度。framebuffer_service.c 执行screencap获取原始的图像数据，再写到socket。

以下是framebuffer_service.c的参考代码：

void framebuffer_service(int fd, void *cookie){    struct fbinfo fbinfo;    unsigned int i;    char buf[640];    int fd_screencap;    int w, h, f;    int fds[2];    if (pipe(fds) < 0) goto done;    pid_t pid = fork();    if (pid < 0) goto done;    if (pid == 0) {        dup2(fds[1], STDOUT_FILENO);        close(fds[0]);        close(fds[1]);        const char* command = "screencap";        const char *args[2] = {command, NULL};        execvp(command, (char**)args);        exit(1);    }    fd_screencap = fds[0];    /* read w, h & format */    if(readx(fd_screencap, &w, 4)) goto done;    if(readx(fd_screencap, &h, 4)) goto done;    if(readx(fd_screencap, &f, 4)) goto done;    fbinfo.version = DDMS_RAWIMAGE_VERSION;    /* see hardware/hardware.h */    switch (f) {        case 1: /* RGBA_8888 */            fbinfo.bpp = 32;            fbinfo.size = w * h * 4;            fbinfo.width = w;            fbinfo.height = h;            fbinfo.red_offset = 0;            fbinfo.red_length = 8;            fbinfo.green_offset = 8;            fbinfo.green_length = 8;            fbinfo.blue_offset = 16;            fbinfo.blue_length = 8;            fbinfo.alpha_offset = 24;            fbinfo.alpha_length = 8;            break;        case 2: /* RGBX_8888 */             ......        default:            goto done;    }    /* write header */    if(writex(fd, &fbinfo, sizeof(fbinfo))) goto done;    /* write data */    for(i = 0; i < fbinfo.size; i += sizeof(buf)) {      if(readx(fd_screencap, buf, sizeof(buf))) goto done;      if(writex(fd, buf, sizeof(buf))) goto done;    }    if(readx(fd_screencap, buf, fbinfo.size % sizeof(buf))) goto done;    if(writex(fd, buf, fbinfo.size % sizeof(buf))) goto done;done:    TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));    close(fds[0]);    close(fds[1]);    close(fd);}

有耐心的朋友可以看看adb源码、ddmlib源码

adb源码：android源码内/system/core/adb

ddmlib源码：http://www.boyunjian.com/javasrc/com.google.android.tools/ddmlib/r13/_/com/android/ddmlib/

Forwarding Ports

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