Groovy example source code file (CachedField.java)

This example Groovy source code file (CachedField.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

cachedfield, cannot, cannot, field, groovyruntimeexception, groovyruntimeexception, illegalaccessexception, illegalaccessexception, metaproperty, object, object, reflection

The Groovy CachedField.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.reflection;

import groovy.lang.GroovyRuntimeException;
import groovy.lang.MetaProperty;
import org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;

public class CachedField extends MetaProperty {
    public final Field field;

    public CachedField(Field field) {
        super (field.getName(), field.getType());
        this.field = field;
    }

    public boolean isStatic() {
        return Modifier.isStatic(getModifiers());
    }

    public boolean isFinal() {
        return Modifier.isFinal(getModifiers());
    }

    public int getModifiers() {
        return field.getModifiers();
    }

    /**
     * @return the property of the given object
     * @throws RuntimeException if the property could not be evaluated
     */
    public Object getProperty(final Object object) {
        try {
            return field.get(object);
        } catch (IllegalAccessException e) {
            throw new GroovyRuntimeException("Cannot get the property '" + name + "'.", e);
        }
    }

    /**
     * Sets the property on the given object to the new value
     *
     * @param object on which to set the property
     * @param newValue the new value of the property
     * @throws RuntimeException if the property could not be set
     */
    public void setProperty(final Object object, Object newValue) {
        final Object goalValue = DefaultTypeTransformation.castToType(newValue, field.getType());

        if (isFinal()) {
            throw new GroovyRuntimeException("Cannot set the property '" + name + "' because the backing field is final.");
        }
        try {
            field.set(object, goalValue);
        } catch (IllegalAccessException ex) {
            throw new GroovyRuntimeException("Cannot set the property '" + name + "'.", ex);
        }
    }
}