浅析Java基于Socket的文件传输案例

package com.wf.demo.socket.socketfile; 
 
import java.net.*; 
import java.io.*; 
 
/** 
 * 2.socket的Util辅助类 
 * 
 * @author willson 
 * 
 */ 
public class ClientSocket { 
 
  private String ip; 
 
  private int port; 
 
  private Socket socket = null; 
 
  DataOutputStream out = null; 
 
  DataInputStream getMessageStream = null; 
 
  public ClientSocket(String ip, int port) { 
    this.ip = ip; 
    this.port = port; 
  } 
 
  /** 
   * 创建socket连接 
   * 
   * @throws Exception 
   *       exception 
   */ 
  public void CreateConnection() throws Exception { 
 
    try { 
      socket = new Socket(ip, port); 
    } catch (Exception e) { 
      e.printStackTrace(); 
      if (socket != null) 
        socket.close(); 
      throw e; 
    } finally { 
    } 
  } 
 
  // 发送消息 
  public void sendMessage(String sendMessage) throws Exception { 
    try { 
      out = new DataOutputStream(socket.getOutputStream()); 
      if (sendMessage.equals("Windows")) { 
        out.writeByte(0x1); 
        out.flush(); 
        return; 
      } 
      if (sendMessage.equals("Unix")) { 
        out.writeByte(0x2); 
        out.flush(); 
        return; 
      } 
      if (sendMessage.equals("Linux")) { 
        out.writeByte(0x3); 
        out.flush(); 
      } else { 
        out.writeUTF(sendMessage); 
        out.flush(); 
      } 
    } catch (Exception e) { 
      e.printStackTrace(); 
      if (out != null) 
        out.close(); 
      throw e; 
    } finally { 
    } 
  } 
 
  // 接受消息 
  public DataInputStream getMessageStream() throws Exception { 
    try { 
      getMessageStream = new DataInputStream(new BufferedInputStream( 
          socket.getInputStream())); 
      return getMessageStream; 
    } catch (Exception e) { 
      e.printStackTrace(); 
      if (getMessageStream != null) 
        getMessageStream.close(); 
      throw e; 
    } finally { 
    } 
  } 
 
  // 关闭连接 
  public void shutDownConnection() { 
    try { 
      if (out != null) 
        out.close(); 
      if (getMessageStream != null) 
        getMessageStream.close(); 
      if (socket != null) 
        socket.close(); 
    } catch (Exception e) { 
    } 
  } 
} 

package com.wf.demo.socket.socketfile; 
 
import java.io.BufferedInputStream; 
import java.io.DataInputStream; 
import java.io.DataOutputStream; 
import java.io.File; 
import java.io.FileInputStream; 
import java.net.ServerSocket; 
import java.net.Socket; 
 
/** 
 * 1.服务器端 
 * 
 * @author willson 
 * 
 */ 
public class ServerTest { 
   
  int port = 8821; 
 
  void start() { 
     
    Socket socket = null; 
     
    try { 
       
      ServerSocket serverSocket = new ServerSocket(port); 
       
      while (true) { 
        // 选择进行传输的文件 
        String filePath = "E:\\lib.zip"; 
         
        File fi = new File(filePath); 
 
        System.out.println("File Name：" + fi.getName() + ";\tFile Size()：" + (int) fi.length() + "bytes"); 
 
        // public Socket accept() throws 
        // IOException侦听并接受到此套接字的连接。此方法在进行连接之前一直阻塞。 
 
         
        System.out.println("等待客户端连接，连接端口：" + port); 
        socket = serverSocket.accept(); 
         
        System.out.println("建立socket链接"); 
         
        DataInputStream dis = new DataInputStream(new BufferedInputStream(socket.getInputStream())); 
         
        dis.readByte(); 
 
        DataInputStream fis = new DataInputStream(new BufferedInputStream(new FileInputStream(filePath))); 
         
        DataOutputStream ps = new DataOutputStream(socket.getOutputStream()); 
         
        // 将文件名及长度传给客户端。这里要真正适用所有平台，例如中文名的处理，还需要加工，具体可以参见Think In Java 
        // 4th里有现成的代码。 
        ps.writeUTF(fi.getName()); 
        ps.flush(); 
        ps.writeLong((long) fi.length()); 
        ps.flush(); 
 
        int bufferSize = 8192; 
        byte[] buf = new byte[bufferSize]; 
 
        while (true) { 
           
          int read = 0; 
          if (fis != null) { 
            read = fis.read(buf); 
          } 
 
          if (read == -1) { 
            break; 
          } 
          ps.write(buf, 0, read); 
        } 
         
        ps.flush(); 
        // 注意关闭socket链接哦，不然客户端会等待server的数据过来， 
        // 直到socket超时，导致数据不完整。 
        fis.close(); 
        socket.close(); 
         
        System.out.println("文件传输完成\n"); 
      } 
 
    } catch (Exception e) { 
      e.printStackTrace(); 
    } 
  } 
 
  public static void main(String arg[]) { 
    new ServerTest().start(); 
  } 
} 
 
 

package com.wf.demo.socket.socketfile; 
 
import java.io.BufferedOutputStream; 
import java.io.DataInputStream; 
import java.io.DataOutputStream; 
import java.io.FileOutputStream; 
 
/** 
 * 3.客户端 
 * 
 * @author willson 
 * 
 */ 
public class ClientTest { 
 
  private ClientSocket cs = null; 
 
  private String ip = "localhost";// 设置成服务器IP 
 
  private int port = 8821; 
 
  private String sendMessage = "Windwos"; 
 
  public ClientTest() { 
 
    try { 
      if (createConnection()) { 
        sendMessage(); 
        getMessage("F:\\"); 
      } 
    } catch (Exception ex) { 
      ex.printStackTrace(); 
    } 
  } 
 
  private boolean createConnection() { 
     
    cs = new ClientSocket(ip, port); 
    try { 
      cs.CreateConnection(); 
      System.out.print("连接服务器成功!" + "\n"); 
      return true; 
    } catch (Exception e) { 
      System.out.print("连接服务器失败!" + "\n"); 
      return false; 
    } 
 
  } 
 
  private void sendMessage() { 
     
    if (cs == null) 
      return; 
    try { 
      cs.sendMessage(sendMessage); 
    } catch (Exception e) { 
      System.out.print("发送消息失败!" + "\n"); 
    } 
  } 
 
  private void getMessage(String savePath) { 
     
    if (cs == null) 
      return; 
    DataInputStream inputStream = null; 
    try { 
      inputStream = cs.getMessageStream(); 
    } catch (Exception e) { 
      System.out.print("接收消息缓存错误\n"); 
      return; 
    } 
 
    try { 
       
      // 本地保存路径，文件名会自动从服务器端继承而来。 
      int bufferSize = 8192; 
      byte[] buf = new byte[bufferSize]; 
      int passedlen = 0; 
      long len = 0; 
 
      savePath += inputStream.readUTF(); 
      DataOutputStream fileOut = new DataOutputStream(new BufferedOutputStream(new BufferedOutputStream(new FileOutputStream(savePath)))); 
      len = inputStream.readLong(); 
 
      System.out.println("File Size()：" + len + "bytes"); 
      System.out.println("开始接收文件!" + "\n"); 
 
      while (true) { 
         
        int read = 0; 
        if (inputStream != null) { 
          read = inputStream.read(buf); 
        } 
        passedlen += read; 
        if (read == -1) { 
          break; 
        } 
        // 下面进度条本为图形界面的prograssBar做的，这里如果是打文件，可能会重复打印出一些相同的百分比 
        System.out.println("文件接收了" + (passedlen * 100 / len) + "%\n"); 
        fileOut.write(buf, 0, read); 
      } 
      System.out.println("接收完成，文件存为" + savePath + "\n"); 
 
      fileOut.close(); 
    } catch (Exception e) { 
      System.out.println("接收消息错误" + "\n"); 
      return; 
    } 
  } 
 
  public static void main(String arg[]) { 
    new ClientTest(); 
  } 
}