socket 收發報文小程序

需要注意，由於是從文件讀取，而WINDOWS自帶的文本文檔程序，親測對於UTF-8文件會不可見地在文件頭多出3個字節。另外回車換行也是不可見字節，需要考慮到。

package com.test.common.socket;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;

import javax.xml.parsers.ParserConfigurationException;

import org.xml.sax.SAXException;

/**
 * @author Alive
 */
public class SendTest {
    private static final int serverport = 20009;

    public SendTest() {
    }

    public static void main(String[] args) throws IOException, SAXException, ParserConfigurationException {
        SendTest sendTest = new SendTest();
        sendTest.sendMsg();
    }

    public void sendMsg() throws IOException, SAXException, ParserConfigurationException {
        BufferedReader bufferedReader = null;
        PrintWriter pw = null;
        
        //文件輸入
        InputStream fileInputStream = this.getClass().getResourceAsStream("msg.txt");
        BufferedInputStream buff = new BufferedInputStream(fileInputStream);
        
        try {
            InetAddress serveraddr = InetAddress.getLocalHost();
            Socket socket = new Socket(serveraddr, 18000);
            bufferedReader =  new BufferedReader(new InputStreamReader(socket.getInputStream()));
            pw = new PrintWriter(socket.getOutputStream(),true);//true代表即時刷新
            
            System.out.println("buff.available(): "+buff.available());
            byte[] data1 = new byte[buff.available()];
            buff.read(data1);
            byte[] data2 = new byte[data1.length-3];
            //去掉UTF-8文件中的前三個字節
            System.arraycopy(data1, 3, data2, 0, data2.length);
            
            //發送
            String str = new String(data1,"UTF-8");
            pw.write(str.trim());    
            pw.flush();
            System.out.println("send: "+str.trim());
            
            //接收
            StringBuilder sb = new StringBuilder();
            String recvStr = null; 
            while((recvStr = bufferedReader.readLine())!=null)
                sb.append(recvStr+"\n");
            System.out.println("recv: "+sb.toString());
            
            socket.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public void show(byte[] bytes) {
        System.out.print("send: ");
        for (int i = 0; i < bytes.length; i++) {
            System.out.print(bytes[i]+" ");
        }
        System.out.println();
    }
}