（6）Socket接收文件 Java

本文描述java如何创建网络服务器，并且发送文件给客户端接收。

一、服务端

package serverSocket;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class MyService {

 public static void main(String[] args) throws Exception {
  // TODO Auto-generated method stub
  ServerSocket ser = new ServerSocket(12345);
  Socket sc =  ser.accept();
  System.out.println("连接客户端"+sc.getInetAddress());
  //从sc中获取流，网络IO流
  InputStream in = sc.getInputStream();
  OutputStream out = sc.getOutputStream();
  //为了简化操作，创建过滤流
  ObjectOutputStream oos = new ObjectOutputStream(out);
  ObjectInputStream ois = new ObjectInputStream(in);
  
  File src = new File("E:\\Users\\Long\\Downloads\\JavaDemo\\Upload\\退伍军人就业平台建设方案.docx");
  
  //发送文件名
  oos.writeObject(src.getName());
  System.out.println("向客户端发送文件名:"+src.getName());
  oos.flush();
  //接收客户端已有文件大小
  long overSize = ois.readLong();
  System.out.println("接收客户端文件大小:"+overSize);
  
  if (overSize==src.length()) {
   oos.writeObject("bu");
   oos.flush();
   System.out.println("告诉客户端不发送:");
  }else {
   oos.writeObject("xc");
   oos.flush();
   System.out.println("向客户端发送文件名");
   
   //文件输入流，把文件读取到java中
   InputStream fileStream = new FileInputStream(src);
   
   byte[] bs= new byte[1024*128];//创建1K大小的缓冲区
   
   fileStream.skip(overSize);
   for (int len = 0; (len=fileStream.read(bs))!=-1;) {
    out.write(bs);//写入网络
   }
   System.out.println("文件发送完成！！！");
   fileStream.close();
  }
  

  
  sc.close();
  ser.close();
 }

}

二、客户端

package clientSocket;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;



public class FileClient {

 public static void main(String[] args) throws Exception {
  Socket sc = new Socket("192.168.2.10",12345);
  System.out.println("成功连接到服务器");
  //从sc中获取流，网络IO流
  InputStream in = sc.getInputStream();
  OutputStream out = sc.getOutputStream();
  //为了简化操作，创建过滤流
  ObjectInputStream ois = new ObjectInputStream(in);
  ObjectOutputStream oos =new ObjectOutputStream(out);
  
  //接收文件名
  String fileName = (String) ois.readObject();
  System.out.println("接收文件名:"+fileName);
  
  File xin = new File("E:\\Users\\Long\\Downloads\\JavaDemo\\DownLoad",fileName);
  //告诉服务器文件大小，服务器进行比较
  oos.writeLong(xin.length());
  oos.flush();
  System.out.println("发送已有文件大小给服务端");
  
  //接收服务器响应,xc代表续传,xin重头传,bu不传
  
  String order = (String)ois.readObject();
  System.out.println("读取服务端信息:"+order);
  if("xc".equals(order)) {//断点续传
   OutputStream fileOut = new FileOutputStream(xin,true);
   System.out.println("开始接收文件:"+xin.getAbsolutePath());
   
   int n=0;
   byte[] bs = new byte[1024*128];
   for (int len = 0; (len = in.read(bs))!=-1; n++) {
    fileOut.write(bs,0,len);//从网络读取，写入到文件
   }
   System.out.println("文件接收完成！！！次数="+n);
   fileOut.close();
  }else if ("bu".equals(order)) {
   System.out.println("文件妥妥的，无需下载");
  }
  
  
  
 }

}