abstractgdatarequesthandler.java

一套java版本的搜索引擎源码

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.lucene.gdata.servlet.handler;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.lucene.gdata.server.GDataRequest;
import org.apache.lucene.gdata.server.GDataRequestException;
import org.apache.lucene.gdata.server.GDataResponse;
import org.apache.lucene.gdata.server.Service;
import org.apache.lucene.gdata.server.ServiceFactory;
import org.apache.lucene.gdata.server.GDataRequest.GDataRequestType;
import org.apache.lucene.gdata.server.registry.ComponentType;
import org.apache.lucene.gdata.server.registry.GDataServerRegistry;

/**
 * @author Simon Willnauer
 * 
 */
public abstract class AbstractGdataRequestHandler extends RequestAuthenticator implements
        GDataRequestHandler {
    private final static Log LOG = LogFactory
            .getLog(AbstractGdataRequestHandler.class);
    /*
     * UTF-8 is the encoding used in the client API to send the entries to the server
     */
    private final static String ENCODING = "UTF-8";
    protected Service service;
    protected GDataRequest feedRequest;
    protected GDataResponse feedResponse;

    /**
     * @see org.apache.lucene.gdata.servlet.handler.GDataRequestHandler#processRequest(javax.servlet.http.HttpServletRequest,
     *      javax.servlet.http.HttpServletResponse)
     */
    public abstract void processRequest(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException;

    protected void initializeRequestHandler(final HttpServletRequest request, final HttpServletResponse response, final GDataRequestType type)
            throws GDataRequestException, ServletException {
        this.feedRequest = new GDataRequest(request, type);
        this.feedResponse = new GDataResponse(response);
        this.feedResponse.setEncoding(ENCODING);
        
        try {       
            this.feedRequest.initializeRequest();
        } catch (GDataRequestException e) {
            setError(e.getErrorCode());
            LOG.warn("Couldn't initialize FeedRequest - " + e.getMessage(), e);
            throw e;
        }
        getService(this.feedRequest);
    }

    

    protected void sendError() throws IOException {
        this.feedResponse.sendError();
        
    }

	protected void setFeedResponseFormat() {
		this.feedResponse.setOutputFormat(this.feedRequest.getRequestedResponseFormat());
	}

	protected void setFeedResponseStatus(int status) {
		this.feedResponse.setResponseCode(status);
	}

	protected void setError(int error) {
		this.feedResponse.setError(error);
	}

    private void getService(GDataRequest request) throws ServletException {
        GDataServerRegistry registry = GDataServerRegistry.getRegistry();
        ServiceFactory serviceFactory = registry.lookup(ServiceFactory.class,ComponentType.SERVICEFACTORY);
        this.service = serviceFactory.getService(request);
        if(this.service == null)
            throw new ServletException("Service not available"); 
        
    }
    
    protected void closeService(){
        this.service.close();
    }



}