Commons Digester example source code file (CompoundTransform.java)

This example Commons Digester source code file (CompoundTransform.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Digester tags/keywords

compoundtransform, linkedlist, linkedlist, plugincreaterule, plugincreaterule, string, string, transform, transform, util

The Commons Digester CompoundTransform.java source code

/*
 * 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.
 */ 

import java.util.LinkedList;
import java.util.Iterator;

import org.apache.commons.digester.Digester;
import org.apache.commons.digester.plugins.PluginCreateRule;

/**
 * An implementation of the Transform interface which is configured with
 * a sequence of "subtransforms", and applies them one by one to the input
 * data.
 * <p>
 * This demonstrates that a plugged-in class can itself define plugin-points 
 * for user-defined classes if it wishes.
 */

public class CompoundTransform implements Transform {
    private LinkedList transforms = new LinkedList();
    
    public void addTransform(Transform transform) {
        transforms.add(transform);
    }
    
    public String transform(String s) {
        for(Iterator i = transforms.iterator(); i.hasNext(); ) {
            Transform t = (Transform) i.next();
            s = t.transform(s);
        }
        return s;
    }
    
    public static void addRules(Digester d, String patternPrefix) {
        PluginCreateRule pcr = new PluginCreateRule(Transform.class);
        d.addRule(patternPrefix+"/subtransform", pcr);
        d.addSetNext(patternPrefix+"/subtransform", "addTransform");
    }
}