Groovy example source code file (ClassExtender.java)

This example Groovy source code file (ClassExtender.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 - Groovy tags/keywords

classextender, classextender, closure, closure, hashmap, map, map, object, object, util

The Groovy ClassExtender.java source code

/*
 * Copyright 2003-2007 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.codehaus.groovy.runtime;

import groovy.lang.Closure;

import java.util.HashMap;
import java.util.Map;


/**
 * A helper class used by the runtime to allow Groovy classes to be extended at runtime
 * 
 * @author <a href="mailto:james@coredevelopers.net">James Strachan
 * @version $Revision: 6778 $
 */
public class ClassExtender {
    private Map variables;
    private Map methods;

    public synchronized Object get(String name) {
        if (variables != null) {
            return variables.get(name);
        }
        return null;
    }

    public synchronized void set(String name, Object value) {
        if (variables == null) {
            variables = createMap();
        }
        variables.put(name, value);
    }

    public synchronized void remove(String name) {
        if (variables != null) {
            variables.remove(name);
        }
    }

    public void call(String name, Object params) {
        Closure closure = null;
        synchronized (this) {
            if (methods != null) {
                closure = (Closure) methods.get(name);
            }
        }
        if (closure != null) {
            closure.call(params);
        }
        /*
        else {
            throw DoesNotUnderstandException();
        }
        */
    }

    public synchronized void addMethod(String name, Closure closure) {
        if (methods == null) {
            methods = createMap();
        }
        methods.put(name, methods);
    }

    public synchronized void removeMethod(String name) {
        if (methods != null) {
            methods.remove(name);
        }
    }

    protected Map createMap() {
        return new HashMap();
    }
}