《安卓网络编程》之第七篇 java编写Service程序

 import java.io.*;
 import java.awt.*;
 import java.awt.event.*;
 import javax.swing.*;
 import java.net.*;
 import java.util.*;

 class Conn extends Thread{
     private JTextArea txt;
     private Socket st;
     private String msg = null;
     private BufferedReader br = null;
     private PrintStream ps;
     public Conn(Socket st,JTextArea txt){
         this.st = st;
         this.txt = txt;
         start();
     }
     public void run(){
         try{
             br = new BufferedReader(new InputStreamReader(st.getInputStream()));
             ps = new PrintStream(new DataOutputStream(st.getOutputStream()));
         }catch(Exception e){
             System.err.println("input failed");
         }
         while(true){
             try{
                 msg = br.readLine();//阻塞方法
                 txt.append("从客户端收到信息:"+msg+'\n');
                 txt.append("信息接受时间是:"+new Date()+"\n");
                 //创建读取文件线程，并将读取到的内容通过服务器发送出去
                 FileThread ft = new FileThread();
                 Thread t = new Thread(ft);
                 t.start();
                 while(ft.flag);
                 System.out.println(ft.readData);
                 Server.send(ft.readData);

             }catch(Exception e){
                 System.err.println("connection closed");
                 break;
             }
         }
     }
     public void send(String msg){
       ps.println(msg);
     }

 }

 class FileThread implements Runnable{
     public String readData = "";
     public static boolean flag = true;
     public void run() {
         readData = readFileByLines("D:\\Hello.txt");
         flag = false;
         System.out.println(readData);
     }

     /**
      * 以行为单位读取文件，常用于读面向行的格式化文件
      */
     public String readFileByLines(String fileName) {
         File file = new File(fileName);
         BufferedReader reader = null;
         String tempString = null;
         String readData = "";
         try {
             System.out.println("以行为单位读取文件内容，一次读一整行：");
             reader = new BufferedReader(new FileReader(file));
             int line = 1;

             // 一次读入一行，直到读入null为文件结束
             while ((tempString = reader.readLine()) != null) {
                 // 显示行号
 //                System.out.println("line " + line + ": " + tempString);
 //                line++;
                 readData = readData.concat(tempString);//字符串拼接推荐函数
             }
             reader.close();
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             if (reader != null) {
                 try {
                     reader.close();
                 } catch (IOException e1) {
                 }
             }
         }

         return  readData;
     }

 }

 public class Server extends JFrame{
     private JTextArea txt;
     private ServerSocket ss;
     public String tempString = null;
     private static java.util.List<Conn> conns = new ArrayList<Conn>();
     public Server(){
        txt = new JTextArea();
        this.setTitle("服务器");
        this.setLayout(new BorderLayout());
        this.add(new JScrollPane(txt),BorderLayout.CENTER);
        this.setSize(500,300);
        this.setVisible(true);

        run();
     }
     public void run(){
         try{
             ss = new ServerSocket(3000);
         }catch(Exception e){
             System.err.println("open socket failed");
         }
         txt.append("服务器已经启动！"+"\n");
         while(true){
             try{
                 Socket st=ss.accept();
                 conns.add(new Conn(st,txt));
             }
             catch(IOException ex){
                 System.err.println(ex);
             }
         }
     }
     public static void send(String msg){
       for(Conn c:conns)
         c.send(msg);
     }

     public static void main(String args[]){

         Server myserver=new Server();
      }

 }

另外一种写法：