ServerMain.java

package com.mtools.core.plugin.socket;

import java.io.*; 
import java.net.ServerSocket; 
import java.net.Socket; 
 
public class ServerMain { 
     
    public static void main(String[] args) { 
 
        class SocketThread extends Thread{ 
             
            private Socket socket; 
            private byte[] buf; 
            private int len = 0; 
            public SocketThread(Socket socket) {  
                this.socket = socket; 
                buf = new byte[1024]; 
            } 
 
            @Override 
            public void run() { 
                try {    
                    DataInputStream dis = new DataInputStream(socket.getInputStream()); 
                    DataOutputStream dos = new DataOutputStream(socket.getOutputStream());  
                     
                    //String command = dis.readUTF();  
                    len = dis.read(buf); 
                    String command = new String(buf,0,len); 
                     
                    System.out.println("command=="+command); 
                     
                    String[] temp =command.split(" "); 
                    command = temp[0];  //命令  是put还是get 
                    String filename = temp[1];  //文件名 
                     
                    File file = new File("C:\\",filename);//假设放在C盘 
                    if(command.equals("get")){ 
                        if(!file.exists()){ 
                            //dos.writeUTF("notexists"); 
                            dos.write("notexists".getBytes()); 
                            dos.flush(); 
                            System.out.println("没有这个文件，无法提供下载！"); 
                            dis.close(); 
                            dos.close(); 
                            socket.close(); 
                            return; 
                        } 
                        //dos.writeUTF("DownloadReady "+file.length());  
                        dos.write("准备下载".getBytes()); 
                        dos.flush(); 
                         
                        System.out.println("正在接受文件下载..."); 
                        DataInputStream fis = new DataInputStream(new BufferedInputStream(new FileInputStream(file)));  
   
                        while ((len = fis.read(buf))!= -1) {  
                            dos.write(buf, 0, len); 
                        } 
                        dos.flush(); 
                         
                        fis.close();      
                        System.out.println("文件传输完成"); 
                    } 
                    else {  
                        //dos.writeUTF("UploadReady");  
                        dos.write("UploadReady".getBytes()); 
                        dos.flush(); 
                         
                        System.out.println("正在接受文件上传..."); 
                        DataOutputStream fileOut =  
                            new DataOutputStream(new BufferedOutputStream(new FileOutputStream(file))); 
  
                        while ((len = dis.read(buf))!=-1) {    
                            fileOut.write(buf, 0, len); 
                        } 
                        System.out.println("上传完毕！"); 
                        fileOut.close();  
                    } 
                    dis.close(); 
                    dos.close(); 
                    socket.close();  
                } catch (Exception e) { 
                    e.printStackTrace(); 
                } 
            } 
             
        } 
         
        System.out.println("等待客户端连接...."); 
        int index = 0; 
        try { 
            ServerSocket server = new ServerSocket(9527,300); //端口号9527  允许最大连接数300 
            while (true) { 
                Socket socket = server.accept(); 
                System.out.println("收到第"+(++index)+"个连接"); 
                new SocketThread(socket).start(); //对每个连接创建一个线程 
            } 
        } catch (Exception e) { 
            e.printStackTrace(); 
        } 
    } 
}