《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+'
');
                txt.append("信息接受时间是:"+new Date()+"
");
                //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！"+"
");
        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：