non-releases/trunk_before_flattening/src/java/org/apache/cocoon/sitemap/SitemapErrorHandler.java

/*
 * Copyright 2005 The Apache Software Foundation.
 *
 * Licensed 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.cocoon.sitemap;

import org.apache.cocoon.Processor;
import org.apache.cocoon.components.treeprocessor.InvokeContext;
import org.apache.cocoon.components.treeprocessor.sitemap.ErrorHandlerHelper;
import org.apache.cocoon.environment.Environment;

/**
 * Class providing error handling capabilities to the pipeline
 * as configured in the sitemap.
 *
 * @since 2.1.7
 * @version $Id$
 */
public class SitemapErrorHandler {
    /**
     * Error handler helper of the pipeline node
     */
    private ErrorHandlerHelper handler;

    /**
     * Environment of the pipeline node
     */
    private Environment environment;

    /**
     * Sitemap invocation context
     */
    private InvokeContext context;

    // Environment state
    private String envPrefix;
    private String envURI;

    /**
     * Construct error handler with everything needed to handle an error.
     */
    public SitemapErrorHandler(ErrorHandlerHelper handler,
                               Environment environment,
                               InvokeContext context) {
        this.handler = handler;
        this.environment = environment;
        this.context = context;

        this.envPrefix = environment.getURIPrefix();
        this.envURI = environment.getURI();
    }

    /**
     * Handle an error.
     * @return true if error was handled.
     */
    public boolean handleError(Exception e) throws Exception {
        // Restore environment state
        this.environment.setURI(this.envPrefix, this.envURI);

        return this.handler.invokeErrorHandler(e, this.environment, this.context);
    }

    /**
     * Build error handling pipeline.
     * @return error handling pipeline, or null if error was not handled.
     */
    public Processor.InternalPipelineDescription prepareErrorPipeline(Exception e) throws Exception {
        // Restore environment state
        this.environment.setURI(this.envPrefix, this.envURI);

        return this.handler.prepareErrorHandler(e, this.environment, this.context);
    }
}