用java能做哪些简单的网络通信方面的软件

给你一个吧。
基础的网络聊天程序
一共两个文件
先运行ChatServer

//ChatServer.java
import java.io.*;
import java.net.*;
import java.util.*;

public class ChatServer {
boolean started = false;
ServerSocket ss = null;

List<Client> clients = new ArrayList<Client>();

public static void main(String[] args) {
new ChatServer().start();
}

public void start() {
try {
ss = new ServerSocket(8888);
started = true;
} catch (BindException e) {
System.out.println("端口使用中....");
System.out.println("请关掉相关程序并重新运行服务器！");
System.exit(0);
} catch (IOException e) {
e.printStackTrace();
}

try {

while(started) {
Socket s = ss.accept();
Client c = new Client(s);
System.out.println("a client connected!");
new Thread(c).start();
clients