• 1 单线程上传
  

        1)SERVER

package fileUpLoad;

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Random;

public class Server {
	public static void main(String[] args) throws IOException {
		//创建对象绑定端口
		ServerSocket ss = new ServerSocket(9999);
		//获得socket对象
		Socket s = ss.accept();
		InetAddress ipObj = s.getInetAddress();
		System.out.println(ipObj.getHostAddress()+"登录服务器。");
		//获得输入流
		InputStream in = s.getInputStream();
		Random ran = new Random();
		BufferedOutputStream fileOut = new BufferedOutputStream(new FileOutputStream("/home/alex/images/" + ran.nextInt(9999) + ".jpg"));
		//将socket流中的数据写入fileout流中
		byte[] buf = new byte[1024];
		int len = -1;
		while( (len = in.read(buf)) != -1 ) {
			fileOut.write(buf, 0, len);
		}
		//反馈信息
		OutputStream out = s.getOutputStream();
		String str = ipObj.getHostAddress()+ "图片复制成功。";
		out.write(str.getBytes());
		//关闭资源
		in.close();
		out.close();
		fileOut.close();
		s.close();
	}
}

        2)Client

package fileUpLoad;

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

public class Client {
	
	public static void main(String[] args) throws IOException {
		//创建客户端，链接服务器
		Socket socket = new Socket("127.0.0.1", 9999);
		//获得输出流，用来写文件到服务器
		OutputStream out = socket.getOutputStream();
		//获得图片的输入流
		BufferedInputStream fileIn = new BufferedInputStream(new FileInputStream("/home/alex/images/11.jpeg"));
		//将图片流写入到服务器
		byte[] buf = new byte[1024];
		int len = -1;
		while( (len = fileIn.read(buf)) != -1 ) {
			out.write(buf, 0, len);		
		}
		//客户端发送数据完毕，结束Socket输出流的写入操作，告知服务器端
		socket.shutdownOutput();
		//获得反馈信息
		InputStream in = socket.getInputStream();
		int length = in.read(buf);
		System.out.println(new String(buf, 0, length));
		//关闭资源
		socket.close();
		in.close();
		out.close();
		fileIn.close();
	}
	
}

• 2 多线程文件上传

        多线程文件上传只涉及修改服务器端，客户端不用修改用之前的就行。

        1)Server

package fileUpLoad;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class MultiThreadServer {

	public static void main(String[] args) throws IOException {
		// 创建对象绑定端口
		ServerSocket ss = new ServerSocket(9999);
		while (true) {
			// 客户端套接字
			Socket clientSocket = ss.accept();
			//匿名内部类实现多线程
			new Thread() {
				public void run() {
					try {
						String clientIP = clientSocket.getInetAddress().getHostAddress();
						System.out.println(clientIP + "登录服务器。");
						// 获得文件输出流

						File path = new File("/home/alex/images/" + clientIP);
						if(!path.exists()) {
							path.mkdir();
						}
						FileOutputStream file;
						BufferedOutputStream fileOut = new BufferedOutputStream(new FileOutputStream(path.getAbsolutePath()+ "/" +System.currentTimeMillis() +".jpg"));
						// 获得输入流
						InputStream clientIn = clientSocket.getInputStream();
						byte[] buf = new byte[1024];
						int len = -1;
						while ((len = clientIn.read(buf)) != -1) {
							fileOut.write(buf);
						}
						// 反馈信息
						// 获得客户端输出流
						OutputStream out = clientSocket.getOutputStream();
						out.write("文件上传完毕.".getBytes());
						// 关闭资源
						clientIn.close();
						clientSocket.close();
						fileOut.close();
						out.close();
					}catch(IOException e) {
						e.printStackTrace();
					}
				}
			}.start();
		}
	}
}