通过服务器向指定客户端发送消息

1HashMap的遍历向每一个socket发送数据

public HashMap<String, Socket> sockets = new HashMap();
try { 
            Set<String>set=sockets.keySet();
            Iterator<String>it=set.iterator();

        while(it.hasNext()){
                OutputStream os = socket.getOutputStream();
                BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(os));
                String words = textArea.getText();
                System.out.println("服务器发送信息");
                bw.write(words + "\n");
                bw.flush();
            }

2服务器一直处于读的状态，把读到的信息传递给解析方法

public void run() {
        InputStream is;
        try {
            is = socket.getInputStream();
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);
            while (server.isRunning()) {// 别忘记方法的括号
                String line = br.readLine();//把读到的信息赋给 line（JSON格式）
                server.readLine(line);//调用MyServer的方法穿入信息并解析
                System.out.println(line);
            }
        } catch (IOException e) {

            e.printStackTrace();
        }

3此方法解析客户端传来的信息并直接转发给目的接受客户端

public void readLine(String line) {
        System.out.println("开始解析这个信息"+line);
        JSONObject obj=JSONObject.fromObject(line);
        String type=obj.getString("type");

        if(type.equals("toSingle")){
            String msg=obj.getString("message");
            String to=obj.getString("to");
            String from=obj.getString("from");
            String time=obj.getString("time");
            Socket toSocket=sockets.get(to);//查询数组中匹配to的IP的socket。得到socket 付给toSocket
            System.out.println(toSocket.getInetAddress().getHostAddress());//输出目的主机地址
             OutputStream os;
            try {
                os = toSocket.getOutputStream();
                 BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(os));
                 bw.write(msg+"\n");
                 bw.flush();

            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }
        model.addElement(line);//服务器窗口传入收到信息