netterminal.java

j2me实现的移动机器人代码（Java实现）

package name.lxm.robot.arch.module;

import name.lxm.robot.arch.*;
import name.lxm.robot.arch.util.*;
import java.io.*;
import java.net.*;

/**
 * This class is used to transmit and recieve messages (text based)
 * between two modules throught the ethernet <br><br>
 * 
 * It can be refered from the name that this class is implemented
 * based on http protocol. That's true, and the command is delivered
 * by use of the method ``get'', therefore it is should not be too 
 * long (less 1024 bytes theoretically).
 */
public class NetTerminal extends AbstractModule
{
	private String[] port_names = {"data_in", "data_out"};
	private SimpleInPort in_port;
	private SimpleOutPort out_port;
	private String conn_string;
	private String verify_string;
	private ServerSocket ssocket;
	int listenPort;
	
	public void valueUpdated()
	{
		String msg = in_port.getValue().toString();
		new HttpSender(conn_string, msg).start();
	}


	public void run()
	{
		while(bRun)
		{
			acceptConnection();
		}
	}

	public Port getPort(String name)
	{
		if(port_names[0].equals("data_in"))
			return in_port;
		if(port_names[1].equals("data_out"))
			return out_port;
		return null;
	}

	public void init(ModuleDoc doc) throws Exception
	{
		super.init(doc);
		in_port = new SimpleInPort(this, port_names[0]);
		out_port = new SimpleOutPort(this, port_names[1]);
		in_port.registerListener(this);
		String server_string = doc.getParamValue("server_string");
		String server_port = doc.getParamValue("server_port");
		verify_string = doc.getParamValue("verify_string");
		conn_string = "http://"+server_string+":"+server_port+"/"+verify_string;
		String s = doc.getParamValue("listen_port");
		if(s == null) throw new IllegalXMLFormatException("listen_port is required for the module " + module_name);
		listenPort = Integer.parseInt(s);
		ssocket = new ServerSocket(listenPort);
	}	

	private void acceptConnection()
	{
		Socket s;
		BufferedReader br ;
		PrintWriter pw;
		String line;
		boolean bValid = false;

		try{
			s = ssocket.accept();
			System.out.println("A connection comes in!");
			br = new BufferedReader(new InputStreamReader(s.getInputStream()));
			pw = new PrintWriter(new OutputStreamWriter(s.getOutputStream()));
			int p = 0;
			while((line = br.readLine()) != null)
			{
				System.out.println(line);
				if(line.equals(""))
					break;
				if((p=line.indexOf(verify_string)) != -1)
				{
					bValid = true;
					//extract the company command string
					int ep = line.indexOf("HTTP/1.1");
					String ss = line.substring(p+verify_string.length()+1, ep);
					ss = URLDecoder.decode(ss, "UTF-8");
					System.out.println("Incoming Command: " + ss);
					out_port.setValue(this, ss, 1000);
					break;
				}
			}
			if(!bValid)
				pw.println("Unwelcome connection.");
			else
			{
				pw.println("HTTP/1.1 200 OK");
				pw.println("Content-type:text/xml");
				pw.println();
				pw.println("Hello, " + s.toString());
			}
			pw.close();
			br.close();
			s.close();
		}catch(Exception e)
		{
			if(! (e instanceof SocketException))
				e.printStackTrace();
		}
	}

	public void start() throws Exception
	{
		super.start();
	}

	
	public void stop() throws Exception
	{
		bRun = false;
		ssocket.close();
		super.stop();
	}
}