jahiaapplicationcontextbaseservice.java

java 写的一个新闻发布系统

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//    _______|  /--|    |    |    -   \  _    |    :    -   \_________
//   \\______: :---|    :    :           |    :    |         \________>
//           |__\---\_____________:______:    :____|____:_____\
//                                      /_____|
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//                 . . . i n   j a h i a   w e   t r u s t . . .
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//  NK      18.06.2002
//
//


package org.jahia.services.applications;


import java.io.*;
import java.text.*;
import java.util.*;

import javax.servlet.*;					            // ServletException
import javax.servlet.http.*;			            // HttpServletRequest, HttpSerlvetResponse

import javax.xml.parsers.SAXParser;
import org.xml.sax.helpers.ParserAdapter;
import org.xml.sax.EntityResolver;

import org.jahia.data.webapps.*;      	// JahiaWebAppsDef
import org.jahia.data.applications.*; 	// ApplicationBean
import org.jahia.utils.*;       		// JahiaConsole
import org.jahia.utils.xml.*;      		// DtdEntityResolver
import org.jahia.exceptions.*;  		// JahiaException
import org.jahia.services.*;    		// JahiaService
import org.jahia.registries.*;        	// ServicesRegistry
import org.jahia.settings.*;          	// JahiaPrivateSettings


/**
 * Application context manager service.
 *
 * @author Khue Nguyen <a href="mailto:[e-mail]">[e-mail]</a>
 * @version 1.0
 */
public class JahiaApplicationContextBaseService extends JahiaApplicationContextService {

    private static final String CLASS_NAME = JahiaApplicationContextBaseService.class.getName();

    /** the DTD Entity Resolver we use with local dtd files **/
    private static EntityResolver mResolver ;

    /** The web.xml file **/
    private static final String WEB_XML_FILE = "/WEB-INF/web.xml";

	/** the instance **/
	private static JahiaApplicationContextBaseService mInstance = null;

	/** the cache of application context beans **/
	private Hashtable mRegistry = new Hashtable();

    /** The Server ServerContext **/
    private ServletContext mContext;


	//--------------------------------------------------------------------------
	/**
	 * constructor
	 *
	 */
	protected JahiaApplicationContextBaseService(){
    	JahiaConsole.println( "JahiaApplicationContextBaseService",
       	"***** Starting the Jahia Application Context Manager Base Service *****" );
	}

	//--------------------------------------------------------------------------
	/**
	 * return the singleton instance
	 */
	public static synchronized JahiaApplicationContextBaseService getInstance(){
		
		if ( mInstance == null ){
			mInstance = new JahiaApplicationContextBaseService();
		}
		
		return mInstance;
	}
	
	//--------------------------------------------------------------------------
    /***
     * Services initializations
     *
     * @param JahiaPrivateSettings jSettings
     */
    public void init( JahiaPrivateSettings jSettings )
    throws JahiaInitializationException
    {
        if (!isInitialized ()) {
			mContext				= jSettings.context;
            mResolver 				= (EntityResolver)jSettings.getDtdEntityResolver();
            mIsServiceInitialized = true;
        }
    }

	//--------------------------------------------------------------------------
	/**
	 * Get an ApplicationContext for a given application id
	 *
	 * @param id , the application id
	 * @return the application context , null if not found
	 */
	public ApplicationContext getApplicationContext(int id) 
	throws JahiaException {

	    JahiaConsole.println("JahiaApplicationContextBaseService.getApplicationContext",
	                         "Requested application : [" + id +"]" );
		
		ApplicationBean appBean = ServicesRegistry.getInstance()
													.getJahiaApplicationsManagerService()
													.getApplication(id);
		if ( appBean == null ){
			String errMsg = "Error getting application bean for application [" + id + "]";
		    JahiaConsole.println("JahiaApplicationContextBaseService",errMsg);

           	throw new JahiaException(errMsg,errMsg,
                                    JahiaException.ERROR,
                                    JahiaException.APPLICATION_ERROR);
		}
		
		return getApplicationContext(appBean.getContext());
	}

	//--------------------------------------------------------------------------
	/**
	 * Get an ApplicationContext for a given context
	 *
	 * @param context , the context
	 * @return the application context , null if not found
	 */
	public ApplicationContext getApplicationContext(String context) 
	throws JahiaException {

	    JahiaConsole.println("JahiaApplicationContextBaseService.getApplicationContext",
	                         "Requested for context : " + context );
		
		if ( context == null ){
			return null;
		}
		ApplicationContext appContext = null;
		synchronized ( mRegistry ){
			appContext = (ApplicationContext)mRegistry.get(context);			
			if ( appContext == null ){
				// try to load from disk
				appContext = loadContextInfoFromDisk(context);
			}
			if ( appContext == null ){
				// create a fake Application Context to avoid loading from disk the next time.
				appContext = new ApplicationContext(context);                     
			}
			mRegistry.put(context,appContext);
		}
		return appContext;
	}

	//--------------------------------------------------------------------------
	/**
	 * Returns a ApplicationContext bean with the information loaded from the web.xml
	 * file of a given context
	 *
	 * @param context , the context
	 * @return an ApplicationContext or null on error
	 */
	private ApplicationContext loadContextInfoFromDisk( String context ) throws JahiaException {

		ServletContext dispatchedContext = mContext.getContext(context);    
		if (dispatchedContext == null) {
		    JahiaConsole.println("JahiaApplicationContextBaseService",
		                        "Error getting dispatch context [" +
		                         context + "]");

           throw new JahiaException("Can't access context " +
                                    context,
                                    "Error getting request context " + context,
                                    JahiaException.ERROR,
                                    JahiaException.APPLICATION_ERROR);
		}			

		String path = dispatchedContext.getRealPath(WEB_XML_FILE);		            	
		JahiaConsole.println("JahiaApplicationContextBaseService",
		                 		 "dispatched context real Path :  " + path );
		
		// extract data from the web.xml file
		ApplicationContext appContext = null;
		Web_App_Xml webXmlDoc = new Web_App_Xml(path);
		webXmlDoc.extractDocumentData();
				
		appContext = new ApplicationContext( context,
											 webXmlDoc.getDisplayName(),
											 webXmlDoc.getdesc(),
											 new Vector(),
											 webXmlDoc.getServletMappings(),
											 new Vector(),
											 webXmlDoc.getWelcomeFiles() );

		Vector servlets = webXmlDoc.getServlets();
		Servlet_Element servlet = null;
		ServletBean servletBean = null;
		for ( int i=0 ; i<servlets.size(); i++ ){
			servlet = (Servlet_Element)servlets.get(i);						
            servletBean = new ServletBean(
                                            servlet.getType(),
                                            servlet.getDisplayName(),
                                            servlet.getName(),
                                            servlet.getSource(),
                                            context,
                                            servlet.getdesc()
                                         );
        	appContext.addServlet(servletBean);                            
		}

		Vector roles = webXmlDoc.getRoles();
		Security_Role role = null;
		for ( int i=0 ; i<roles.size(); i++ ){
			role = (Security_Role)roles.get(i);						
        	appContext.addRole(role.getName());                            
		}
											 
		return appContext;
	}

}