org.jpublish.page.filesystem.FileSystemPageIterator.java Source code

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Here is the source code for org.jpublish.page.filesystem.FileSystemPageIterator.java

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/*
 * Copyright 2004-2007 the original author or authors.
 *
 * 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.jpublish.page.filesystem;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Iterator;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.jpublish.JPublishRuntimeException;

/** Iterator which iterates through the Page objects known to the specified
   PageManager.  This implementation wraps an iterator which returns paths
   and loads the Page object for each path.
       
   @author Anthony Eden
   @since 1.1
*/

public class FileSystemPageIterator implements Iterator {

    private static final Log log = LogFactory.getLog(FileSystemPageIterator.class);

    private AbstractFileSystemPageManager pageManager;
    private Iterator iter;

    /**   Construct a new FileSystemPageIterator.
        
       @param pageManager The PageManager
       @param iter The Iterator to wrap
    */

    public FileSystemPageIterator(AbstractFileSystemPageManager pageManager, Iterator iter) {
        this.pageManager = pageManager;
        this.iter = iter;
    }

    /** Returns true if the iteration has more elements. (In other words, 
       returns true if next would return an element rather than throwing 
       an exception.)
           
       @return True if the iteration has more elements
    */

    public boolean hasNext() {
        return iter.hasNext();
    }

    /**   Returns the next element in the iteration.
        
       @return The next element in the iteration
    */

    public Object next() {
        String root = pageManager.getRoot().toString();
        File file = (File) iter.next();
        String path = file.toString().substring(root.length());
        if (log.isDebugEnabled())
            log.debug("Next path: " + path);

        try {
            return pageManager.getPage(path);
        } catch (FileNotFoundException e) {
            log.warn("FileNotFoundException while retrieving path: " + path);
            return next();
        } catch (Exception e) {
            log.error("Error getting page: " + path);
            throw new JPublishRuntimeException(e.getMessage(), e);
        }
    }

    /**   Removes from the underlying collection the last element returned by 
       the iterator (optional operation). This method can be called only 
       once per call to next. The behavior of an iterator is unspecified 
       if the underlying collection is modified while the iteration is in 
       progress in any way other than by calling this method. 
        
       @throws UnsupportedOperationException
    */

    public void remove() {
        throw new UnsupportedOperationException();
    }

}