要做成这样的：
客户端访问服务器ip和port，服务器马上发送welcome消息，然后客户端根据welcome消息判断是否是想要连接的服务器和端口，
如果是则开始发送数据，数据包括开始和结束的校验。服务器端发送welcome消息后开始接收数据，直到结束。蛮简单的事TMD我怎么就搞不定。
CLIENT：
package com.ces.mytest.socket;
import java.net.*;
import java.io.*;
public class ClientThread extends Thread {
private String ipStr = "";
private int port;
public ClientThread(String ipStr, int port) {
this.ipStr = ipStr;
this.port = port;
}
public void run() {
try {
Socket client = new Socket(ipStr, port);
BufferedReader read = new BufferedReader(new InputStreamReader(client.getInputStream()));
BufferedWriter write = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));
if ("欢迎".equals(read.readLine())) {
System.out.println("校验正确");
write.write("开始");
write.newLine();
write.write("数据");
write.newLine();
write.write("结束");
write.newLine();
write.flush();
System.out.println("发送完毕");
}
write.close();
read.close();
client.close();
} catch (UnknownHostException ex) {
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
}
}
public static void main(String[] args) {
