向服务器上传文件

//客户端

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;

public class ClientDemo111 {

	public static void main(String[] args) throws Exception, IOException {
		File file = getFile();
		Socket s =new Socket("192.168.1.103",7878);
		BufferedReader br =new BufferedReader(new InputStreamReader(s.getInputStream()));
		PrintStream ps = new PrintStream(s.getOutputStream());
		ps.println(file.getName());
		String lineString = br.readLine();
		if(lineString.equals("存在")){
			System.out.println("文件已存在,请不要重复上传");
			s.close();
			return;
		}
		FileInputStream fis = new FileInputStream(file);
		int len;
		 byte[] arr =new byte[1024];
		 while((len =fis.read(arr))!=-1){
			 ps.write(arr, 0, len);
		 }
		 fis.close();
		 s.close();
		
	}

	private static File getFile() {
		System.out.println("请输入一个文件路径:");
		Scanner sc = new Scanner(System.in);
		while (true) {
			String line = sc.nextLine();
			File file = new File(line);
			if (!file.exists()) {
				System.out.println("你输入的文件不存在,重新输入");
			} else if (file.isDirectory()) {
				System.err.println("你输入的是文件路径,请重新输入");
			} else {
				sc.close();
				return file;
			}
		}

	}

}import java.io.BufferedReader;
import j