//向指定ip發(fā)送信息
public static void main(String[] args) throws Exception{
    Socket s=new Socket(InetAddress.getByName(InetAddress.getLocalHost().getHostAddress()),10000);
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    //封裝輸出流對(duì)象
    BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
    String line;
    while (true) {
        if ((line=br.readLine())!=null){
            if("1024".equals(line)) {
                bw.write(line);
                bw.newLine();
                break;
            }
            bw.write(line);
            bw.newLine();
        }
        bw.flush();
        //獲取輸出流對(duì)象
    }
    //釋放資源
    s.close();
}

//接收發(fā)送到本機(jī)的信息
ServerSocket socket=new ServerSocket(10000);
Socket accept = socket.accept();
BufferedReader br = new BufferedReader(new InputStreamReader(accept.getInputStream()));
String line;
while ((line=br.readLine())!=null){
    System.out.println(line);
}

//創(chuàng)建發(fā)送端的Socket對(duì)象(DatagramSocket)
//創(chuàng)建數(shù)據(jù)，并把數(shù)據(jù)打包
//DatagramPacket(byte[] buf, int length, InetAddress address, int port)
//構(gòu)造一個(gè)數(shù)據(jù)包，發(fā)送長(zhǎng)度為 length的數(shù)據(jù)包到指定主機(jī)上的指定端口號(hào)。

DatagramSocket ds = new DatagramSocket();
byte[] bys = "hello,udp,我來(lái)了".getBytes();
        DatagramPacket dp = new DatagramPacket(bys,bys.length,  InetAddress.getByName("10.102.13.18"),10086);
        //調(diào)用DatagramSocket對(duì)象的方法發(fā)送數(shù)據(jù)
        //void send(DatagramPacket p) 從此套接字發(fā)送數(shù)據(jù)報(bào)包
        ds.send(dp);
        System.out.println("已發(fā)送："+new String(dp.getData(),0,dp.getLength()));
        //關(guān)閉發(fā)送端
        //void close() 關(guān)閉此數(shù)據(jù)報(bào)套接字
        ds.close();

DatagramSocket ds = new DatagramSocket(10086);
while (true) {
    //創(chuàng)建一個(gè)數(shù)據(jù)包，用于接收數(shù)據(jù)
    byte[] bys = new byte[1024];
    DatagramPacket dp = new DatagramPacket(bys, bys.length);
    //調(diào)用DatagramSocket對(duì)象的方法接收數(shù)據(jù)
    ds.receive(dp);
    System.out.println("-----");
    //解析數(shù)據(jù)包，并把數(shù)據(jù)在控制臺(tái)顯示
    System.out.println("數(shù)據(jù)是：" + new String(dp.getData(), 0, dp.getLength()));
}