PC客户端与Android服务端的Socket同步通信（USB）

需求：

     1.一个android端的service后台运行的程序，作为socket的服务器端;用于接收Pc client端发来的命令，来处理数据后，把结果发给PC client

     2.PC端程序，作为socket的客户端，用于给android手机端发操作命令

难点分析：

     1.手机一定要有adb模式，即插上USB线时马上提示的对话框选adb。好多对手机的操作都可以用adb直接作。

        不过，我发现LG GW880就没有，要去下载个

     2.android默认手机端的IP为“127.0.0.1”

     3.要想联通PC与android手机的sokcet，一定要用adb forward 来作下端口转发才能连上socket.

Runtime.getRuntime().exec("adb forward tcp:12580 tcp:10086");
            Thread.sleep(3000);

 

       4.android端的service程序Install到手机上容易，但是还要有方法来从PC的client端来启动手机上的service ，这个办法可以通过PC端adb命令来发一个Broastcast ，手机端再写个接收BroastcastReceive来接收这个Broastcast，在这个BroastcastReceive来启动service

     

    pc端命令：

  

Runtime.getRuntime().exec(
"adb shell am broadcast -a NotifyServiceStart");

 

 android端的代码:ServiceBroadcastReceiver.java

 

package com.otheri.service;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

public class ServiceBroadcastReceiver extends BroadcastReceiver {
    private static String START_ACTION = "NotifyServiceStart";
    private static String STOP_ACTION = "NotifyServiceStop";

    @Override
    public void onReceive(Context context, Intent intent) {
        Log.d(androidService.TAG, Thread.currentThread().getName() + "---->"
                + "ServiceBroadcastReceiver onReceive");

        String action = intent.getAction();
        if (START_ACTION.equalsIgnoreCase(action)) {
            context.startService(new Intent(context, androidService.class));

            Log.d(androidService.TAG, Thread.currentThread().getName() + "---->"
                    + "ServiceBroadcastReceiver onReceive start end");
        } else if (STOP_ACTION.equalsIgnoreCase(action)) {
            context.stopService(new Intent(context, androidService.class));
            Log.d(androidService.TAG, Thread.currentThread().getName() + "---->"
                    + "ServiceBroadcastReceiver onReceive stop end");
        }
    }

}

 

  5.由于是USB连接，所以socket就可以设计为一但连接就一直联通，即在new socket和开完out,in流后，就用个while(true){}来循环PC端和android端的读和写

    android的代码：

public void run() {
        Log.d(androidService.TAG, Thread.currentThread().getName() + "---->"
                + "a client has connected to server!");
        BufferedOutputStream out;
        BufferedInputStream in;
        try {
            /* PC端发来的数据msg */
            String currCMD = "";
            out = new BufferedOutputStream(client.getOutputStream());
            in = new BufferedInputStream(client.getInputStream());
            // testSocket();// 测试socket方法
            androidService.ioThreadFlag = true;
            while (androidService.ioThreadFlag) {
                try {
                    if (!client.isConnected()) {
                        break;
                    }

                    /* 接收PC发来的数据 */
                    Log.v(androidService.TAG, Thread.currentThread().getName()
                            + "---->" + "will read......");
                    /* 读操作命令 */
                    currCMD = readCMDFromSocket(in);
                    Log.v(androidService.TAG, Thread.currentThread().getName()
                            + "---->" + "**currCMD ==== " + currCMD);

                    /* 根据命令分别处理数据 */
                    if (currCMD.equals("1")) {
                        out.write("OK".getBytes());
                        out.flush();
                    } else if (currCMD.equals("2")) {
                        out.write("OK".getBytes());
                        out.flush();
                    } else if (currCMD.equals("3")) {
                        out.write("OK".getBytes());
                        out.flush();
                    } else if (currCMD.equals("4")) {
                        /* 准备接收文件数据 */
                        try {
                            out.write("service receive OK".getBytes());
                            out.flush();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }

                        /* 接收文件数据，4字节文件长度，4字节文件格式，其后是文件数据 */
                        byte[] filelength = new byte[4];
                        byte[] fileformat = new byte[4];
                        byte[] filebytes = null;

                        /* 从socket流中读取完整文件数据 */
                        filebytes = receiveFileFromSocket(in, out, filelength,
                                fileformat);

                        // Log.v(Service139.TAG, "receive data =" + new
                        // String(filebytes));
                        try {
                            /* 生成文件 */
                            File file = FileHelper.newFile("R0013340.JPG");
                            FileHelper.writeFile(file, filebytes, 0,
                                    filebytes.length);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    } else if (currCMD.equals("exit")) {

                    }
                } catch (Exception e) {
                    // try {
                    // out.write("error".getBytes("utf-8"));
                    // out.flush();
                    // } catch (IOException e1) {
                    // e1.printStackTrace();
                    // }
                    Log.e(androidService.TAG, Thread.currentThread().getName()
                            + "---->" + "read write error111111");
                }
            }
            out.close();
            in.close();
        } catch (Exception e) {
            Log.e(androidService.TAG, Thread.currentThread().getName()
                    + "---->" + "read write error222222");
            e.printStackTrace();
        } finally {
            try {
                if (client != null) {
                    Log.v(androidService.TAG, Thread.currentThread().getName()
                            + "---->" + "client.close()");
                    client.close();
                }
            } catch (IOException e) {
                Log.e(androidService.TAG, Thread.currentThread().getName()
                        + "---->" + "read write error333333");
                e.printStackTrace();
            }
        }

 

  6.如果是在PC端和android端的读写操作来while(true){}循环，这样socket流的结尾不好判断，不能用“-1”来判断，因为“-1”是只有在socket关闭时才作为判断结尾。

  7.socket在out.write(bytes);时，要是数据太大时，超过socket的缓存，socket自动分包发送，所以对方就一定要用循环来多次读。最好的办法就是服务器和客户端协议好，比如发文件时，先写过来一个要发送的文件的大小，然后再发送文件;对方用这个大小，来循环读取数据。

   android端接收数据的代码:

 

/**
     * 功能：从socket流中读取完整文件数据
     *
     * InputStream in：socket输入流
     *
     * byte[] filelength: 流的前4个字节存储要转送的文件的字节数
     *
     * byte[] fileformat：流的前5-8字节存储要转送的文件的格式（如.apk）
     *
     * */
    public static byte[] receiveFileFromSocket(InputStream in,
            OutputStream out, byte[] filelength, byte[] fileformat) {
        byte[] filebytes = null;// 文件数据
        try {
            int filelen = MyUtil.bytesToInt(filelength);// 文件长度从4字节byte[]转成Int
            String strtmp = "read file length ok:" + filelen;
            out.write(strtmp.getBytes("utf-8"));
            out.flush();

            filebytes = new byte[filelen];
            int pos = 0;
            int rcvLen = 0;
            while ((rcvLen = in.read(filebytes, pos, filelen - pos)) > 0) {
                pos += rcvLen;
            }
            Log.v(androidService.TAG, Thread.currentThread().getName()
                    + "---->" + "read file OK:file size=" + filebytes.length);
            out.write("read file ok".getBytes("utf-8"));
            out.flush();
        } catch (Exception e) {
            Log.v(androidService.TAG, Thread.currentThread().getName()
                    + "---->" + "receiveFileFromSocket error");
            e.printStackTrace();
        }
        return filebytes;
    }

 

 8.socket的最重要的机制就是读写采用的是阻塞的方式，如果客户端作为命令发起者，服务器端作为接收者的话，只有当客户端client用out.writer()写到输出流里后，即流中有数据service的read才会执行，不然就会一直停在read()那里等数据。

 9.还要让服务器端可以同时连接多个client，即服务器端用new thread()来作数据读取操作。

源码：

客户端（pc端）：

testPcClient.java

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;

public class testPcClient {

    /**
     * @param args
     * @throws InterruptedException
     */
    public static void main(String[] args) throws InterruptedException {
        try {
            Runtime.getRuntime().exec(
                    "adb shell am broadcast -a NotifyServiceStop");
            Thread.sleep(3000);
            Runtime.getRuntime().exec("adb forward tcp:12580 tcp:10086");
            Thread.sleep(3000);
            Runtime.getRuntime().exec(
                    "adb shell am broadcast -a NotifyServiceStart");
            Thread.sleep(3000);
        } catch (IOException e3) {
            e3.printStackTrace();
        }

        Socket socket = null;
        try {
            InetAddress serverAddr = null;
            serverAddr = InetAddress.getByName("127.0.0.1");
            System.out.println("TCP 1111" + "C: Connecting...");
            socket = new Socket(serverAddr, 12580);
            String str = "hi,wufenglong";
            System.out.println("TCP 221122" + "C:RECEIVE");
            BufferedOutputStream out = new BufferedOutputStream(socket
                    .getOutputStream());
            BufferedInputStream in = new BufferedInputStream(socket
                    .getInputStream());
            BufferedReader br = new BufferedReader(new InputStreamReader(
                    System.in));
            boolean flag = true;
            while (flag) {
                System.out.print("请输入1~6的数字,退出输入exit：");
                String strWord = br.readLine();// 从控制台输入1~6
                if (strWord.equals("1")) {
                    out.write("1".getBytes());
                    out.flush();
                    System.out.println("1 finish sending the data");
                    String strFormsocket = readFromSocket(in);
                    System.out.println("the data sent by server is:/r/n"
                            + strFormsocket);
                    System.out
                            .println("=============================================");
                } else if (strWord.equals("2")) {
                    out.write("2".getBytes());
                    out.flush();
                    System.out.println("2 finish sending the data");
                    String strFormsocket = readFromSocket(in);
                    System.out.println("the data sent by server is:/r/n"
                            + strFormsocket);
                    System.out
                            .println("=============================================");
                } else if (strWord.equals("3")) {
                    out.write("3".getBytes());
                    out.flush();
                    System.out.println("3 finish sending the data");
                    String strFormsocket = readFromSocket(in);
                    System.out.println("the data sent by server is:/r/n"
                            + strFormsocket);
                    System.out
                            .println("=============================================");
                } else if (strWord.equals("4")) {
                    /* 发送命令 */
                    out.write("4".getBytes());
                    out.flush();
                    System.out.println("send file finish sending the CMD：");
                    /* 服务器反馈：准备接收 */
                    String strFormsocket = readFromSocket(in);
                    System.out
                            .println("service ready receice data:UPDATE_CONTACTS:"
                                    + strFormsocket);
                    byte[] filebytes = FileHelper.readFile("R0013340.JPG");
                    System.out.println("file size=" + filebytes.length);
                    /* 将整数转成4字节byte数组 */
                    byte[] filelength = new byte[4];
                    filelength = tools.intToByte(filebytes.length);
                    /* 将.apk字符串转成4字节byte数组 */
                    byte[] fileformat = null;
                    fileformat = ".apk".getBytes();
                    System.out
                            .println("fileformat length=" + fileformat.length);
                    /* 字节流中前4字节为文件长度，4字节文件格式，以后是文件流 */
                    /* 注意如果write里的byte[]超过socket的缓存，系统自动分包写过去，所以对方要循环写完 */
                    out.write(filelength);
                    out.flush();
                    String strok1 = readFromSocket(in);
                    System.out.println("service receive filelength :" + strok1);
                    // out.write(fileformat);
                    // out.flush();
                    // String strok2 = readFromSocket(in);
                    // System.out.println("service receive fileformat :" +
                    // strok2);
                    System.out.println("write data to android");
                    out.write(filebytes);
                    out.flush();
                    System.out.println("*********");

                    /* 服务器反馈：接收成功 */
                    String strread = readFromSocket(in);
                    System.out.println(" send data success:" + strread);
                    System.out
                            .println("=============================================");
                } else if (strWord.equalsIgnoreCase("EXIT")) {
                    out.write("EXIT".getBytes());
                    out.flush();
                    System.out.println("EXIT finish sending the data");
                    String strFormsocket = readFromSocket(in);
                    System.out.println("the data sent by server is:/r/n"
                            + strFormsocket);
                    flag = false;
                    System.out
                            .println("=============================================");
                }
            }

        } catch (UnknownHostException e1) {
            System.out.println("TCP 331133" + "ERROR:" + e1.toString());
        } catch (Exception e2) {
            System.out.println("TCP 441144" + "ERROR:" + e2.toString());
        } finally {
            try {
                if (socket != null) {
                    socket.close();
                    System.out.println("socket.close()");
                }
            } catch (IOException e) {
                System.out.println("TCP 5555" + "ERROR:" + e.toString());
            }
        }
    }

    /* 从InputStream流中读数据 */
    public static String readFromSocket(InputStream in) {
        int MAX_BUFFER_BYTES = 4000;
        String msg = "";
        byte[] tempbuffer = new byte[MAX_BUFFER_BYTES];
        try {
            int numReadedBytes = in.read(tempbuffer, 0, tempbuffer.length);
            msg = new String(tempbuffer, 0, numReadedBytes, "utf-8");

            tempbuffer = null;
        } catch (Exception e) {
            e.printStackTrace();
        }
        // Log.v(Service139.TAG, "msg=" + msg);
        return msg;
    }
}

 

android服务器端：

主类androidService.java

package com.otheri.service;

import java.io.File;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.IBinder;
import android.util.Log;

/**
 * 设置：android手机
 *
 *
 * */
public class androidService extends Service {
    public static final String TAG = "TAG";
    public static Boolean mainThreadFlag = true;
    public static Boolean ioThreadFlag = true;
    ServerSocket serverSocket = null;
    final int SERVER_PORT = 10086;
    File testFile;
    private sysBroadcastReceiver sysBR;

    @Override
    public void onCreate() {
        super.onCreate();
        Log.v(TAG, Thread.currentThread().getName() + "---->" + "  onCreate");
        /* 创建内部类sysBroadcastReceiver 并注册registerReceiver */
        sysRegisterReceiver();
        new Thread() {
            public void run() {
                doListen();
            };
        }.start();
    }

    private void doListen() {
        Log.d(TAG, Thread.currentThread().getName() + "---->"
                + " doListen() START");
        serverSocket = null;
        try {
            Log.d(TAG, Thread.currentThread().getName() + "---->"
                    + " doListen() new serverSocket");
            serverSocket = new ServerSocket(SERVER_PORT);

            boolean mainThreadFlag = true;
            while (mainThreadFlag) {
                Log.d(TAG, Thread.currentThread().getName() + "---->"
                        + " doListen() listen");

                Socket client = serverSocket.accept();

                new Thread(new ThreadReadWriterIOSocket(this, client)).start();
            }
        } catch (IOException e1) {
            Log.v(androidService.TAG, Thread.currentThread().getName()
                    + "---->" + "new serverSocket error");
            e1.printStackTrace();
        }
    }

    /* 创建内部类sysBroadcastReceiver 并注册registerReceiver */
    private void sysRegisterReceiver() {
        Log.v(TAG, Thread.currentThread().getName() + "---->"
                + "sysRegisterReceiver");
        sysBR = new sysBroadcastReceiver();
        /* 注册BroadcastReceiver */
        IntentFilter filter1 = new IntentFilter();
        /* 新的应用程序被安装到了设备上的广播 */
        filter1.addAction("android.intent.action.PACKAGE_ADDED");
        filter1.addDataScheme("package");
        filter1.addAction("android.intent.action.PACKAGE_REMOVED");
        filter1.addDataScheme("package");
        registerReceiver(sysBR, filter1);
    }

    /* 内部类：BroadcastReceiver 用于接收系统事件 */
    private class sysBroadcastReceiver extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (action.equalsIgnoreCase("android.intent.action.PACKAGE_ADDED")) {
                // ReadInstalledAPP();
            } else if (action
                    .equalsIgnoreCase("android.intent.action.PACKAGE_REMOVED")) {
                // ReadInstalledAPP();
            }
            Log.v(TAG, Thread.currentThread().getName() + "---->"
                    + "sysBroadcastReceiver onReceive");
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();

        // 关闭线程
        mainThreadFlag = false;
        ioThreadFlag = false;
        // 关闭服务器
        try {
            Log.v(TAG, Thread.currentThread().getName() + "---->"
                    + "serverSocket.close()");
            serverSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        Log.v(TAG, Thread.currentThread().getName() + "---->"
                + "**************** onDestroy****************");
    }

    @Override
    public void onStart(Intent intent, int startId) {
        Log.d(TAG, Thread.currentThread().getName() + "---->" + " onStart()");
        super.onStart(intent, startId);

    }

    @Override
    public IBinder onBind(Intent arg0) {
        Log.d(TAG, "  onBind");
        return null;
    }

}

 

用于接收PC发来的Broastcast并启动主类service的ServiceBroadcastReceiver.java

package com.otheri.service;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

public class ServiceBroadcastReceiver extends BroadcastReceiver {
    private static String START_ACTION = "NotifyServiceStart";
    private static String STOP_ACTION = "NotifyServiceStop";

    @Override
    public void onReceive(Context context, Intent intent) {
        Log.d(androidService.TAG, Thread.currentThread().getName() + "---->"
                + "ServiceBroadcastReceiver onReceive");

        String action = intent.getAction();
        if (START_ACTION.equalsIgnoreCase(action)) {
            context.startService(new Intent(context, androidService.class));

            Log.d(androidService.TAG, Thread.currentThread().getName() + "---->"
                    + "ServiceBroadcastReceiver onReceive start end");
        } else if (STOP_ACTION.equalsIgnoreCase(action)) {
            context.stopService(new Intent(context, androidService.class));
            Log.d(androidService.TAG, Thread.currentThread().getName() + "---->"
                    + "ServiceBroadcastReceiver onReceive stop end");
        }
    }

}

 

用于新socket连接的读写线程类ThreadReadWriterIOSocket.java

package com.otheri.service;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

import android.content.Context;
import android.util.Log;

import com.otheri.util.FileHelper;
import com.otheri.util.MyUtil;

/**
 * 功能：用于socket的交互
 *
 * @author wufenglong
 *
 */
public class ThreadReadWriterIOSocket implements Runnable {
    private Socket client;
    private Context context;

    ThreadReadWriterIOSocket(Context context, Socket client) {

        this.client = client;
        this.context = context;
    }

    @Override
    public void run() {
        Log.d(androidService.TAG, Thread.currentThread().getName() + "---->"
                + "a client has connected to server!");
        BufferedOutputStream out;
        BufferedInputStream in;
        try {
            /* PC端发来的数据msg */
            String currCMD = "";
            out = new BufferedOutputStream(client.getOutputStream());
            in = new BufferedInputStream(client.getInputStream());
            // testSocket();// 测试socket方法
            androidService.ioThreadFlag = true;
            while (androidService.ioThreadFlag) {
                try {
                    if (!client.isConnected()) {
                        break;
                    }

                    /* 接收PC发来的数据 */
                    Log.v(androidService.TAG, Thread.currentThread().getName()
                            + "---->" + "will read......");
                    /* 读操作命令 */
                    currCMD = readCMDFromSocket(in);
                    Log.v(androidService.TAG, Thread.currentThread().getName()
                            + "---->" + "**currCMD ==== " + currCMD);

                    /* 根据命令分别处理数据 */
                    if (currCMD.equals("1")) {
                        out.write("OK".getBytes());
                        out.flush();
                    } else if (currCMD.equals("2")) {
                        out.write("OK".getBytes());
                        out.flush();
                    } else if (currCMD.equals("3")) {
                        out.write("OK".getBytes());
                        out.flush();
                    } else if (currCMD.equals("4")) {
                        /* 准备接收文件数据 */
                        try {
                            out.write("service receive OK".getBytes());
                            out.flush();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }

                        /* 接收文件数据，4字节文件长度，4字节文件格式，其后是文件数据 */
                        byte[] filelength = new byte[4];
                        byte[] fileformat = new byte[4];
                        byte[] filebytes = null;

                        /* 从socket流中读取完整文件数据 */
                        filebytes = receiveFileFromSocket(in, out, filelength,
                                fileformat);

                        // Log.v(Service139.TAG, "receive data =" + new
                        // String(filebytes));
                        try {
                            /* 生成文件 */
                            File file = FileHelper.newFile("R0013340.JPG");
                            FileHelper.writeFile(file, filebytes, 0,
                                    filebytes.length);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    } else if (currCMD.equals("exit")) {

                    }
                } catch (Exception e) {
                    // try {
                    // out.write("error".getBytes("utf-8"));
                    // out.flush();
                    // } catch (IOException e1) {
                    // e1.printStackTrace();
                    // }
                    Log.e(androidService.TAG, Thread.currentThread().getName()
                            + "---->" + "read write error111111");
                }
            }
            out.close();
            in.close();
        } catch (Exception e) {
            Log.e(androidService.TAG, Thread.currentThread().getName()
                    + "---->" + "read write error222222");
            e.printStackTrace();
        } finally {
            try {
                if (client != null) {
                    Log.v(androidService.TAG, Thread.currentThread().getName()
                            + "---->" + "client.close()");
                    client.close();
                }
            } catch (IOException e) {
                Log.e(androidService.TAG, Thread.currentThread().getName()
                        + "---->" + "read write error333333");
                e.printStackTrace();
            }
        }
    }

    /**
     * 功能：从socket流中读取完整文件数据
     *
     * InputStream in：socket输入流
     *
     * byte[] filelength: 流的前4个字节存储要转送的文件的字节数
     *
     * byte[] fileformat：流的前5-8字节存储要转送的文件的格式（如.apk）
     *
     * */
    public static byte[] receiveFileFromSocket(InputStream in,
            OutputStream out, byte[] filelength, byte[] fileformat) {
        byte[] filebytes = null;// 文件数据
        try {
            in.read(filelength);// 读文件长度
            int filelen = MyUtil.bytesToInt(filelength);// 文件长度从4字节byte[]转成Int
            String strtmp = "read file length ok:" + filelen;
            out.write(strtmp.getBytes("utf-8"));
            out.flush();

            filebytes = new byte[filelen];
            int pos = 0;
            int rcvLen = 0;
            while ((rcvLen = in.read(filebytes, pos, filelen - pos)) > 0) {
                pos += rcvLen;
            }
            Log.v(androidService.TAG, Thread.currentThread().getName()
                    + "---->" + "read file OK:file size=" + filebytes.length);
            out.write("read file ok".getBytes("utf-8"));
            out.flush();
        } catch (Exception e) {
            Log.v(androidService.TAG, Thread.currentThread().getName()
                    + "---->" + "receiveFileFromSocket error");
            e.printStackTrace();
        }
        return filebytes;
    }

    /* 读取命令 */
    public static String readCMDFromSocket(InputStream in) {
        int MAX_BUFFER_BYTES = 2048;
        String msg = "";
        byte[] tempbuffer = new byte[MAX_BUFFER_BYTES];
        try {
            int numReadedBytes = in.read(tempbuffer, 0, tempbuffer.length);
            msg = new String(tempbuffer, 0, numReadedBytes, "utf-8");
            tempbuffer = null;
        } catch (Exception e) {
            Log.v(androidService.TAG, Thread.currentThread().getName()
                    + "---->" + "readFromSocket error");
            e.printStackTrace();
        }
        // Log.v(Service139.TAG, "msg=" + msg);
        return msg;
    }
}

 

后面是两个辅助类：

package com.otheri.util;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

import com.otheri.service.androidService;

import android.util.Log;

public class FileHelper {
    // private static String FILEPATH = "/data/local/tmp";

    private static String FILEPATH = "/sdcard";

    // private static String FILEPATH = "/tmp";

    public static File newFile(String fileName) {
        File file = null;
        try {
            file = new File(FILEPATH, fileName);
            file.delete();
            file.createNewFile();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return file;
    }

    public static void writeFile(File file, byte[] data, int offset, int count)
            throws IOException {

        FileOutputStream fos = new FileOutputStream(file, true);
        fos.write(data, offset, count);
        fos.flush();
        fos.close();
    }

    public static byte[] readFile(String fileName) throws IOException {
        File file = new File(FILEPATH, fileName);
        file.createNewFile();
        FileInputStream fis = new FileInputStream(file);
        BufferedInputStream bis = new BufferedInputStream(fis);
        int leng = bis.available();
        Log.v(androidService.TAG, "filesize = " + leng);
        byte[] b = new byte[leng];
        bis.read(b, 0, leng);
        // Input in = new Input(fis);
        // byte[] ret = in.readAll();
        // in.close();
        bis.close();
        return b;

    }
}

package com.otheri.util;

import java.io.InputStream;

import android.util.Log;

import com.otheri.service.androidService;

public class MyUtil {
    /* byte[]转Int */
    public static int bytesToInt(byte[] bytes) {
        int addr = bytes[0] & 0xFF;
        addr |= ((bytes[1] << 8) & 0xFF00);
        addr |= ((bytes[2] << 16) & 0xFF0000);
        addr |= ((bytes[3] << 24) & 0xFF000000);
        return addr;
    }

    /* Int转byte[] */
    public static byte[] intToByte(int i) {
        byte[] abyte0 = new byte[4];
        abyte0[0] = (byte) (0xff & i);
        abyte0[1] = (byte) ((0xff00 & i) >> 8);
        abyte0[2] = (byte) ((0xff0000 & i) >> 16);
        abyte0[3] = (byte) ((0xff000000 & i) >> 24);
        return abyte0;
    }




}