UDP通信工具

package com.dobot.androidtools.Tools;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class UdpMessageTool {
    private byte[] bytes = new byte[2048];

    // DatagramSocket代表UDP協(xié)議的Socket,作用就是接收和發(fā)送數(shù)據(jù)報(bào)
    private DatagramSocket mDatagramSocket = null;
    public static UdpMessageTool instance;

    /**
     * 創(chuàng)建UdpMessageTool對(duì)象
     *
     * @throws Exception
     */

    public UdpMessageTool() throws Exception {
        // 初始化DatagramSocket，也可以傳入指定端口號(hào)
        mDatagramSocket = new DatagramSocket();
    }


    /**
     * 設(shè)置超時(shí)時(shí)間
     */
    public final void setTimeOut(final int timeout) throws Exception {
        mDatagramSocket.setSoTimeout(timeout);
    }

    /**
     * 獲取DatagramSocket對(duì)象
     */
    public final DatagramSocket getDatagramSocket() {
        return mDatagramSocket;
    }

    /**
     * 指定的服務(wù)端發(fā)送數(shù)據(jù)信息. 參數(shù)介紹： host 服務(wù)器主機(jī)地址 port 服務(wù)端端口 bytes 發(fā)送的數(shù)據(jù)信息
     */
    public final synchronized void send(final String host, final int port, final byte[] bytes) throws IOException {
        DatagramPacket dp = new DatagramPacket(bytes, bytes.length, InetAddress.getByName(host), port);
        mDatagramSocket.send(dp);
    }

    /**
     * 接收從指定的服務(wù)端發(fā)回的數(shù)據(jù). hostName 服務(wù)端主機(jī) hostPort 服務(wù)端端口 return 服務(wù)端發(fā)回的數(shù)據(jù).
     *
     * @param hostName
     * @param hostPort
     * @return
     */
    public final synchronized String receive(final String hostName,
                                             final int hostPort) {
        DatagramPacket dp = new DatagramPacket(bytes, bytes.length);
        try {
            mDatagramSocket.receive(dp);
        } catch (Exception e) {
            e.printStackTrace();
            return "";
        }
        String result = new String(dp.getData(), 0, dp.getLength());
        return result;
    }


    /**
     * 關(guān)閉udp連接
     */
    public final void close() {
        if (mDatagramSocket != null) {
            try {
                mDatagramSocket.close();
            } catch (Exception ex) {
                ex.printStackTrace();
            }
            mDatagramSocket = null;
        }
    }
}