Android中Socket大文件断点上传示例

什么是Socket?     

所谓Socket通常也称作“套接字”，用于描述IP地址和端口，是一个通信连的句柄，应用程序通常通过“套接字”向网络发送请求或者应答网络请求，它就是网络通信过程中端点的抽象表示。它主要包括以下两个协议：

TCP (Transmission Control Protocol 传输控制协议)：传输控制协议,提供的是面向连接、可靠的字节流服务。当客户和服务器彼此交换数据前，必须先在双方之间建立一个TCP连接，之后才能传输数据。TCP提供超时重发，丢弃重复数据，检验数据，流量控制等功能，保证数据能从一端传到另一端。

UDP (User Datagram Protocl 用户数据报协议)：用户数据报协议，是一个简单的面向数据报的运输层协议。UDP不提供可靠性，它只是把应用程序传给IP层的数据报发送出去，但是并不能保证它们能到达目的地。由于UDP在传输数据报前不用在客户和服务器之间建立一个连接，且没有超时重发等机制，故而传输速度很快。

详细解说如下:

TCP传输和UDP不一样，TCP传输是流式的，必须先建立连接，然后数据流沿已连接的线路(虚电路)传输。因此TCP的数据流不会像UDP数据报一样，每个数据报都要包含目标地址和端口，因为每个数据报要单独路由。TCP传输则只需要在建立连接时指定目标地址和端口就可以了。

形象的讲，TCP就像打电话，UDP就像发电报。宏观上来看UDP是不分客户端和服务端的。通信双方是平等的。微观上来讲只相对一个报文，发送端是客户端，监听端是服务端。发送端把数据报发给路由器就像把电报发给了邮局，后面的事情就是发送者无法控制，也无从知晓的了。所以说是不可靠的，可能会出现报文丢失而无从知晓。就像每张电报都要有收件人一样，每个数据报都要有目的地址和端口。

而TCP每次连接都是分客户端和服务端的。连接的发起者(相当与拨号打电话的人)是客户端，监听者(相当于在电话边等着接电话的人)是服务端。发起者指定要连接的服务器地址和端口(相当于拨号)，监听者通过和发起者三次握手建立连接(相当于听到电话响去接电话)。建立连接后双方可以互相发送和接受数据(打电话)。

Java如何操作Socket?

值得一提的是，Java分别为TCP和UDP提供了相应的类,TCP是java.NET中提供了两个类Socket和ServerSocket，分别用来表示双向连接的客户端和服务端。这是两个封装得非常好的类，使用起来很方便！UDP是java.Net.DatagramSocket.

127.0.0.1是回路地址,用于测试,相当于localhost本机地址,没有网卡,不设DNS都可以访问,端口地址在0~65535之间,其中0~1023之间的端口是用于一些知名的网络服务和应用,用户的普通网络应用程序应该使用1024以上的端口.

Socket通信模型如下：

服务器，使用ServerSocket监听指定的端口，端口可以随意指定（由于1024以下的端口通常属于保留端口，在一些操作系统中不可以随意使用，所以建议使用大于1024的端口），等待客户连接请求，客户连接后，会话产生；在完成会话后，关闭连接。

客户端，使用Java socket通信对网络上某一个服务器的某一个端口发出连接请求，一旦连接成功，打开会话；会话完成后，关闭Socket。客户端不需要指定打开的端口，通常临时的、动态的分配一个1024以上的端口。

TCP网络连接模型：

Android客户端程序代分析:

UploadActivity.java

package com.android.upload;
import java.io.File;
import java.io.OutputStream;
import java.io.PushbackInputStream;
import java.io.RandomAccessFile;
import java.net.Socket;  

import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;  

import com.android.service.UploadLogService;
import com.android.socket.utils.StreamTool; 

public class UploadActivity extends Activity {
  private EditText filenameText;
  private TextView resulView;
  private ProgressBar uploadbar;
  private UploadLogService logService;
  private boolean start=true;
  private Handler handler = new Handler(){
    @Override
    public void handleMessage(Message msg) {
      int length = msg.getData().getInt("size");
      uploadbar.setProgress(length);
      float num = (float)uploadbar.getProgress()/(float)uploadbar.getMax();
      int result = (int)(num * 100);
      resulView.setText(result+ "%");
      if(uploadbar.getProgress()==uploadbar.getMax()){
        Toast.makeText(UploadActivity.this, R.string.success, 1).show();
      }
    }
  };  

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);  

    logService = new UploadLogService(this);
    filenameText = (EditText)this.findViewById(R.id.filename);
    uploadbar = (ProgressBar) this.findViewById(R.id.uploadbar);
    resulView = (TextView)this.findViewById(R.id.result);
    Button button =(Button)this.findViewById(R.id.button);
    Button button1 =(Button)this.findViewById(R.id.stop);
    button1 .setOnClickListener(new OnClickListener() { 

      @Override
      public void onClick(View v) {
        start=false; 

      }
    });
    button.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        start=true;
        String filename = filenameText.getText().toString();
        if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
          File uploadFile = new File(Environment.getExternalStorageDirectory(), filename);
          if(uploadFile.exists()){
            uploadFile(uploadFile);
          }else{
            Toast.makeText(UploadActivity.this, R.string.filenotexsit, 1).show();
          }
        }else{
          Toast.makeText(UploadActivity.this, R.string.sdcarderror, 1).show();
        }
      }
    });
  }
  /**
   * 上传文件
   * @param uploadFile
   */
  private void uploadFile(final File uploadFile) {
    new Thread(new Runnable() {
      @Override
      public void run() {
        try {
          uploadbar.setMax((int)uploadFile.length());
          String souceid = logService.getBindId(uploadFile);
          String head = "Content-Length="+ uploadFile.length() + ";filename="+ uploadFile.getName() + ";sourceid="+
            (souceid==null? "" : souceid)+"\r\n";
          Socket socket = new Socket("192.168.1.78",7878);
          OutputStream outStream = socket.getOutputStream();
          outStream.write(head.getBytes());  

          PushbackInputStream inStream = new PushbackInputStream(socket.getInputStream());
          String response = StreamTool.readLine(inStream);
          String[] items = response.split(";");
          String responseid = items[0].substring(items[0].indexOf("=")+1);
          String position = items[1].substring(items[1].indexOf("=")+1);
          if(souceid==null){//代表原来没有上传过此文件，往数据库添加一条绑定记录
            logService.save(responseid, uploadFile);
          }
          RandomAccessFile fileOutStream = new RandomAccessFile(uploadFile, "r");
          fileOutStream.seek(Integer.valueOf(position));
          byte[] buffer = new byte[1024];
          int len = -1;
          int length = Integer.valueOf(position);
          while(start&&(len = fileOutStream.read(buffer)) != -1){
            outStream.write(buffer, 0, len);
            length += len;
            Message msg = new Message();
            msg.getData().putInt("size", length);
            handler.sendMessage(msg);
          }
          fileOutStream.close();
          outStream.close();
          inStream.close();
          socket.close();
          if(length==uploadFile.length()) logService.delete(uploadFile);
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    }).start();
  }
}

StreamTool.java

package com.android.socket.utils; 

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream; 

public class StreamTool { 

   public static void save(File file, byte[] data) throws Exception {
     FileOutputStream outStream = new FileOutputStream(file);
     outStream.write(data);
     outStream.close();
   } 

   public static String readLine(PushbackInputStream in) throws IOException {
      char buf[] = new char[128];
      int room = buf.length;
      int offset = 0;
      int c;
loop:    while (true) {
        switch (c = in.read()) {
          case -1:
          case '\n':
            break loop;
          case '\r':
            int c2 = in.read();
            if ((c2 != '\n') && (c2 != -1)) in.unread(c2);
            break loop;
          default:
            if (--room < 0) {
              char[] lineBuffer = buf;
              buf = new char[offset + 128];
              room = buf.length - offset - 1;
              System.arraycopy(lineBuffer, 0, buf, 0, offset); 

            }
            buf[offset++] = (char) c;
            break;
        }
      }
      if ((c == -1) && (offset == 0)) return null;
      return String.copyValueOf(buf, 0, offset);
  } 

  /**
  * 读取流
  * @param inStream
  * @return 字节数组
  * @throws Exception
  */
  public static byte[] readStream(InputStream inStream) throws Exception{
      ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
      byte[] buffer = new byte[1024];
      int len = -1;
      while( (len=inStream.read(buffer)) != -1){
        outSteam.write(buffer, 0, len);
      }
      outSteam.close();
      inStream.close();
      return outSteam.toByteArray();
  }
}

UploadLogService.java

package com.android.service; 

import java.io.File; 

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase; 

public class UploadLogService {
  private DBOpenHelper dbOpenHelper; 

  public UploadLogService(Context context){
    this.dbOpenHelper = new DBOpenHelper(context);
  } 

  public void save(String sourceid, File uploadFile){
    SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
    db.execSQL("insert into uploadlog(uploadfilepath, sourceid) values(?,?)",
        new Object[]{uploadFile.getAbsolutePath(),sourceid});
  } 

  public void delete(File uploadFile){
    SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
    db.execSQL("delete from uploadlog where uploadfilepath=?", new Object[]{uploadFile.getAbsolutePath()});
  } 

  public String getBindId(File uploadFile){
    SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
    Cursor cursor = db.rawQuery("select sourceid from uploadlog where uploadfilepath=?",
        new String[]{uploadFile.getAbsolutePath()});
    if(cursor.moveToFirst()){
      return cursor.getString(0);
    }
    return null;
  }
}

DBOpenHelper.java

package com.android.service; 

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper; 

public class DBOpenHelper extends SQLiteOpenHelper { 

  public DBOpenHelper(Context context) {
    super(context, "upload.db", null, 1);
  } 

  @Override
  public void onCreate(SQLiteDatabase db) {
    db.execSQL("CREATE TABLE uploadlog (_id integer primary key autoincrement, uploadfilepath varchar(100), sourceid varchar(10))");
  } 

  @Override
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("DROP TABLE IF EXISTS uploadlog");
    onCreate(db);
  } 

}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  >
<TextView
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="@string/filename"
  /> 

  <EditText
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="022.jpg"
    android:id="@+id/filename"
    /> 

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/button"
    android:id="@+id/button"
    />
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="暂停"
    android:id="@+id/stop"
    />
  <ProgressBar
      android:layout_width="fill_parent"
      android:layout_height="20px"
      style="?android:attr/progressBarStyleHorizontal"
      android:id="@+id/uploadbar"
      />
  <TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:id="@+id/result"
    />
</LinearLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.android.upload"
  android:versionCode="1"
  android:versionName="1.0" > 

  <uses-sdk android:minSdkVersion="8" /> 

  <application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >
    <activity
      android:name=".UploadActivity"
      android:label="@string/app_name" >
      <intent-filter>
        <action android:name="android.intent.action.MAIN" /> 

        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
  </application>
  <!-- 访问网络的权限 -->
  <uses-permission android:name="android.permission.INTERNET"/>
  <!-- 在SDCard中创建与删除文件权限 -->
  <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
  <!-- 往SDCard写入数据权限 -->
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
</manifest>

Java服务端:

SocketServer.javapackage com.android.socket.server; 

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PushbackInputStream;
import java.io.RandomAccessFile;
import java.net.ServerSocket;
import java.net.Socket;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors; 

import com.android.socket.utils.StreamTool; 

public class SocketServer {
  private String uploadPath="D:/uploadFile/";
  private ExecutorService executorService;// 线程池
  private ServerSocket ss = null;
  private int port;// 监听端口
  private boolean quit;// 是否退出
  private Map<Long, FileLog> datas = new HashMap<Long, FileLog>();// 存放断点数据，最好改为数据库存放 

  public SocketServer(int port) {
    this.port = port;
    // 初始化线程池
    executorService = Executors.newFixedThreadPool(Runtime.getRuntime()
        .availableProcessors() * 50);
  } 

  // 启动服务
  public void start() throws Exception {
    ss = new ServerSocket(port);
    while (!quit) {
      Socket socket = ss.accept();// 接受客户端的请求
      // 为支持多用户并发访问，采用线程池管理每一个用户的连接请求
      executorService.execute(new SocketTask(socket));// 启动一个线程来处理请求
    }
  } 

  // 退出
  public void quit() {
    this.quit = true;
    try {
      ss.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  } 

  public static void main(String[] args) throws Exception {
    SocketServer server = new SocketServer(7878);
    server.start();
  } 

  private class SocketTask implements Runnable {
    private Socket socket; 

    public SocketTask(Socket socket) {
      this.socket = socket;
    } 

    @Override
    public void run() {
      try {
        System.out.println("accepted connenction from "
            + socket.getInetAddress() + " @ " + socket.getPort());
        PushbackInputStream inStream = new PushbackInputStream(
            socket.getInputStream());
        // 得到客户端发来的第一行协议数据：Content-Length=143253434;filename=xxx.3gp;sourceid=
        // 如果用户初次上传文件，sourceid的值为空。
        String head = StreamTool.readLine(inStream);
        System.out.println(head);
        if (head != null) {
          // 下面从协议数据中读取各种参数值
          String[] items = head.split(";");
          String filelength = items[0].substring(items[0].indexOf("=") + 1);
          String filename = items[1].substring(items[1].indexOf("=") + 1);
          String sourceid = items[2].substring(items[2].indexOf("=") + 1);
          Long id = System.currentTimeMillis();
          FileLog log = null;
          if (null != sourceid && !"".equals(sourceid)) {
            id = Long.valueOf(sourceid);
            log = find(id);//查找上传的文件是否存在上传记录
          }
          File file = null;
          int position = 0;
          if(log==null){//如果上传的文件不存在上传记录,为文件添加跟踪记录
            String path = new SimpleDateFormat("yyyy/MM/dd/HH/mm").format(new Date());
            File dir = new File(uploadPath+ path);
            if(!dir.exists()) dir.mkdirs();
            file = new File(dir, filename);
            if(file.exists()){//如果上传的文件发生重名，然后进行改名
              filename = filename.substring(0, filename.indexOf(".")-1)+ dir.listFiles().length+ filename.substring(filename.indexOf("."));
              file = new File(dir, filename);
            }
            save(id, file);
          }else{// 如果上传的文件存在上传记录,读取上次的断点位置
            file = new File(log.getPath());//从上传记录中得到文件的路径
            if(file.exists()){
              File logFile = new File(file.getParentFile(), file.getName()+".log");
              if(logFile.exists()){
                Properties properties = new Properties();
                properties.load(new FileInputStream(logFile));
                position = Integer.valueOf(properties.getProperty("length"));//读取断点位置
              }
            }
          } 

          OutputStream outStream = socket.getOutputStream();
          String response = "sourceid="+ id+ ";position="+ position+ "\r\n";
          //服务器收到客户端的请求信息后，给客户端返回响应信息：sourceid=1274773833264;position=0
          //sourceid由服务生成，唯一标识上传的文件，position指示客户端从文件的什么位置开始上传
          outStream.write(response.getBytes()); 

          RandomAccessFile fileOutStream = new RandomAccessFile(file, "rwd");
          if(position==0) fileOutStream.setLength(Integer.valueOf(filelength));//设置文件长度
          fileOutStream.seek(position);//移动文件指定的位置开始写入数据
          byte[] buffer = new byte[1024];
          int len = -1;
          int length = position;
          while( (len=inStream.read(buffer)) != -1){//从输入流中读取数据写入到文件中
            fileOutStream.write(buffer, 0, len);
            length += len;
            Properties properties = new Properties();
            properties.put("length", String.valueOf(length));
            FileOutputStream logFile = new FileOutputStream(new File(file.getParentFile(), file.getName()+".log"));
            properties.store(logFile, null);//实时记录文件的最后保存位置
            logFile.close();
          }
          if(length==fileOutStream.length()) delete(id);
          fileOutStream.close();
          inStream.close();
          outStream.close();
          file = null;
        }
      } catch (Exception e) {
        e.printStackTrace();
      } finally {
        try {
          if(socket != null && !socket.isClosed()) socket.close();
        } catch (IOException e) {}
      }
    } 

  } 

  public FileLog find(Long sourceid) {
    return datas.get(sourceid);
  } 

  // 保存上传记录
  public void save(Long id, File saveFile) {
    // 日后可以改成通过数据库存放
    datas.put(id, new FileLog(id, saveFile.getAbsolutePath()));
  } 

  // 当文件上传完毕，删除记录
  public void delete(long sourceid) {
    if (datas.containsKey(sourceid))
      datas.remove(sourceid);
  } 

  private class FileLog {
    private Long id;
    private String path; 

    public FileLog(Long id, String path) {
      super();
      this.id = id;
      this.path = path;
    } 

    public Long getId() {
      return id;
    } 

    public void setId(Long id) {
      this.id = id;
    } 

    public String getPath() {
      return path;
    } 

    public void setPath(String path) {
      this.path = path;
    } 

  }
}

ServerWindow.javapackage com.android.socket.server; 

import java.awt.BorderLayout;
import java.awt.Frame;
import java.awt.Label;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener; 

public class ServerWindow extends Frame{
  private SocketServer server;
  private Label label; 

  public ServerWindow(String title){
    super(title);
    server = new SocketServer(7878);
    label = new Label();
    add(label, BorderLayout.PAGE_START);
    label.setText("服务器已经启动");
    this.addWindowListener(new WindowListener() {
      @Override
      public void windowOpened(WindowEvent e) {
        new Thread(new Runnable() {
          @Override
          public void run() {
            try {
              server.start();
            } catch (Exception e) {
              e.printStackTrace();
            }
          }
        }).start();
      } 

      @Override
      public void windowIconified(WindowEvent e) {
      } 

      @Override
      public void windowDeiconified(WindowEvent e) {
      } 

      @Override
      public void windowDeactivated(WindowEvent e) {
      } 

      @Override
      public void windowClosing(WindowEvent e) {
         server.quit();
         System.exit(0);
      } 

      @Override
      public void windowClosed(WindowEvent e) {
      } 

      @Override
      public void windowActivated(WindowEvent e) {
      }
    });
  }
  /**
   * @param args
   */
  public static void main(String[] args) {
    ServerWindow window = new ServerWindow("文件上传服务端");
    window.setSize(300, 300);
    window.setVisible(true);
  } 

}

StreamTool.javapackage com.android.socket.utils; 

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream; 

public class StreamTool { 

   public static void save(File file, byte[] data) throws Exception {
     FileOutputStream outStream = new FileOutputStream(file);
     outStream.write(data);
     outStream.close();
   } 

   public static String readLine(PushbackInputStream in) throws IOException {
      char buf[] = new char[128];
      int room = buf.length;
      int offset = 0;
      int c;
loop:    while (true) {
        switch (c = in.read()) {
          case -1:
          case '\n':
            break loop;
          case '\r':
            int c2 = in.read();
            if ((c2 != '\n') && (c2 != -1)) in.unread(c2);
            break loop;
          default:
            if (--room < 0) {
              char[] lineBuffer = buf;
              buf = new char[offset + 128];
              room = buf.length - offset - 1;
              System.arraycopy(lineBuffer, 0, buf, 0, offset); 

            }
            buf[offset++] = (char) c;
            break;
        }
      }
      if ((c == -1) && (offset == 0)) return null;
      return String.copyValueOf(buf, 0, offset);
  } 

  /**
  * 读取流
  * @param inStream
  * @return 字节数组
  * @throws Exception
  */
  public static byte[] readStream(InputStream inStream) throws Exception{
      ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
      byte[] buffer = new byte[1024];
      int len = -1;
      while( (len=inStream.read(buffer)) != -1){
        outSteam.write(buffer, 0, len);
      }
      outSteam.close();
      inStream.close();
      return outSteam.toByteArray();
  } 

}

运行效果如下:

Android前端控制:

后台监控日志:

下载后的文件路径:

源码下载地址：AndroidSocket_jb51.rar

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