starsserverconnector.java

《Java网络程序设计.rar》包括三个网络程序的源代码。

/*
 * StarsServerConnector.java
 *
 * Created on January 14, 2002, 11:58 PM
 */

package org.impact.stars.appclient.common;

import java.util.*;
import java.io.*;
import java.net.*;
import java.sql.Date;
import javax.swing.JTextArea;


import org.impact.stars.appclient.util.ClientUtil;
import org.impact.stars.control.event.StarsEventSupport;
/**
 *
 * @author  cai
 * @version
 *
 * This Class is the shared server connector for data model tranasmittion
 */
public class StarsServerConnector {
    
    JTextArea statusTextArea = null;
    /** Creates new StarsServerConnector */
    public StarsServerConnector() {
    }
    
    protected void setStatusTextArea(JTextArea sa)
    {
        statusTextArea = sa;
    }
    protected URLConnection getObjectConnectiontoServer(String connection) {
        try{
            log("Connecting to servlet...");
            URL connectionURL = new URL( connection );
            URLConnection servletConnection = connectionURL.openConnection();
            log("Connected");
            
            // inform the connection that we will send output and accept input
            servletConnection.setDoInput(true);
            servletConnection.setDoOutput(true);
            
            // Don't used a cached version of URL connection.
            servletConnection.setUseCaches(false);
            log("SET REQUEST PROPERTY");
            
            // Specify the content type that we will send binary data
            servletConnection.setRequestProperty
            ("Content-Type", "application/octet-stream");
            return servletConnection;
        }
        catch (Exception ex) {
            System.out.println(ex);
        }
        return null;
    }
    
        protected URLConnection getNormalConnectiontoServer(String connection) {
        try{
            log("Connecting to servlet...");
            URL connectionURL = new URL( connection );
            URLConnection servletConnection = connectionURL.openConnection();
            log("Connected");
            
            // inform the connection that we will send output and accept input
            servletConnection.setDoInput(true);
            servletConnection.setDoOutput(true);
            
            // Don't used a cached version of URL connection.
            servletConnection.setUseCaches(false);
            log("SET REQUEST PROPERTY");
            
            return servletConnection;
        }
        catch (Exception ex) {
            System.out.println(ex);
        }
        return null;
    }

    /**
     *  Reads a response from the servlet.
     */
    protected String readServletResponse(URLConnection servletConnection) {
        BufferedReader inFromServlet = null;
        
        try {
            // now, let's read the response from the servlet.
            // this is simply a confirmation string
            inFromServlet = new BufferedReader(new InputStreamReader(servletConnection.getInputStream()));
            String str ="";
            String line;
            while (null != ((line = inFromServlet.readLine()))) {
                log("Reading servlet response: " + line + "; ");
                str= str + line;
            }
            
            inFromServlet.close();
            return str;
        }
        catch (IOException e) {
            log(e.toString());
        }
        return "NO Response";
        //return "OK";
    }

      /**
     *  Sends a perspective object to a servlet.  The perspective object is serialized over the URL connection
     */
    protected void sendEventToServlet(URLConnection servletConnection, StarsEventSupport theEvent) {
        ObjectOutputStream outputToServlet = null;
        
        try {
            // send the perspective object to the servlet using serialization
            log("Sending the perspective to the servlet...");
            outputToServlet = new ObjectOutputStream(servletConnection.getOutputStream());
            
            // serialize the object
            outputToServlet.writeObject(theEvent);
            
            outputToServlet.flush();
            outputToServlet.close();
            log("Complete.");
        }
        catch (IOException e) {
            log(e.toString());
        }
    }
    
  
        /**
     * Called whenever the part throws an exception.
     * @param exception java.lang.Throwable
     */
    protected void handleException(java.lang.Throwable exception) {
        
        /* Uncomment the following lines to print uncaught exceptions to stdout */
        // System.out.println("UNCAUGHT EXCEPTION:" + exception);
        exception.printStackTrace(System.out);
    }

        /**
     *  Simple logging method for status message in the text area.
     */
    protected void log(String msg) {
        if (statusTextArea!=null)
        {
        statusTextArea.append(msg + "\n");
        }
        else 
        {
            System.out.println(msg);
        }
          
    }

}