Java基于Socket的文件传输实现方法

本文实例讲述了java基于socket的文件传输实现方法。分享给大家供大家参考，具体如下：

1. java代码如下：

package sterning;
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;
public class servertest {
 int port = 8821;
 void start() {
  socket s = null;
  try {
   serversocket ss = new serversocket(port);
   while (true) {
    // 选择进行传输的文件
    string filepath = "d:\\lib.rar";
    file fi = new file(filepath);
    system.out.println("文件长度:" + (int) fi.length());
    // 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。
    s = ss.accept();
    system.out.println("建立socket链接");
    datainputstream dis = new datainputstream(new bufferedinputstream(s.getinputstream()));
    dis.readbyte();
    datainputstream fis = new datainputstream(new bufferedinputstream(new fileinputstream(filepath)));
    dataoutputstream ps = new dataoutputstream(s.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();
    s.close();    
    system.out.println("文件传输完成");
   }
  } catch (exception e) {
   e.printstacktrace();
  }
 }
 public static void main(string arg[]) {
  new servertest().start();
 }
}

2.socket的util辅助类

package sterning;
import java.net.*;
import java.io.*;
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 {
  }
 }
 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 {
  }
 }
 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 {
  }
 }
 public void shutdownconnection() {
  try {
   if (out != null)
    out.close();
   if (getmessagestream != null)
    getmessagestream.close();
   if (socket != null)
    socket.close();
  } catch (exception e) {
  }
 }
}

3.客户端

package sterning;
import java.io.bufferedoutputstream;
import java.io.datainputstream;
import java.io.dataoutputstream;
import java.io.fileoutputstream;
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();
   }
  } 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() {
  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。
   string savepath = "e:\\";
   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("文件的长度为:" + len + "\n");
   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();
 }
}

希望本文所述对大家java程序设计有所帮助。