Commons Digester example source code file (BeanPropertySetterRule.java)

This example Commons Digester source code file (BeanPropertySetterRule.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

bean, bean, beanpropertysetterrule, beanpropertysetterrule, deprecated, dynabean, exception, exception, javabean, javabean, nosuchmethodexception, override, override, string, string, stringbuffer

The Commons Digester BeanPropertySetterRule.java source code

/* $Id: BeanPropertySetterRule.java 992060 2010-09-02 19:09:47Z simonetripodi $
 *
 * 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.
 */


package org.apache.commons.digester;


import java.beans.PropertyDescriptor;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.DynaBean;
import org.apache.commons.beanutils.DynaProperty;
import org.apache.commons.beanutils.PropertyUtils;


/**
 * <p> Rule implements sets a bean property on the top object
 * to the body text.</p>
 *
 * <p> The property set:

 * <ul>
can be specified when the rule is created
 * <li>or can match the current element when the rule is called.
 *
 * <p> Using the second method and the {@link ExtendedBaseRules} child match
 * pattern, all the child elements can be automatically mapped to properties
 * on the parent object.</p>
 */

public class BeanPropertySetterRule extends Rule {


    // ----------------------------------------------------------- Constructors


    /**
     * <p>Construct rule that sets the given property from the body text.

     *
     * @param digester associated <code>Digester
     * @param propertyName name of property to set
     *
     * @deprecated The digester instance is now set in the {@link Digester#addRule} method. 
     * Use {@link #BeanPropertySetterRule(String propertyName)} instead.
     */
    @Deprecated
    public BeanPropertySetterRule(Digester digester, String propertyName) {

        this(propertyName);

    }

    /**
     * <p>Construct rule that automatically sets a property from the body text.
     *
     * <p> This construct creates a rule that sets the property
     * on the top object named the same as the current element.
     *
     * @param digester associated <code>Digester
     *     
     * @deprecated The digester instance is now set in the {@link Digester#addRule} method. 
     * Use {@link #BeanPropertySetterRule()} instead.
     */
    @Deprecated
    public BeanPropertySetterRule(Digester digester) {

        this();

    }

    /**
     * <p>Construct rule that sets the given property from the body text.

     *
     * @param propertyName name of property to set
     */
    public BeanPropertySetterRule(String propertyName) {

        this.propertyName = propertyName;

    }

    /**
     * <p>Construct rule that automatically sets a property from the body text.
     *
     * <p> This construct creates a rule that sets the property
     * on the top object named the same as the current element.
     */
    public BeanPropertySetterRule() {

        this((String)null);

    }
    
    // ----------------------------------------------------- Instance Variables


    /**
     * Set this property on the top object.
     */
    protected String propertyName = null;


    /**
     * The body text used to set the property.
     */
    protected String bodyText = null;


    // --------------------------------------------------------- Public Methods


    /**
     * Process the body text of this element.
     *
     * @param namespace the namespace URI of the matching element, or an 
     *   empty string if the parser is not namespace aware or the element has
     *   no namespace
     * @param name the local name if the parser is namespace aware, or just 
     *   the element name otherwise
     * @param text The text of the body of this element
     */
    @Override
    public void body(String namespace, String name, String text)
        throws Exception {

        // log some debugging information
        if (digester.log.isDebugEnabled()) {
            digester.log.debug("[BeanPropertySetterRule]{" +
                    digester.match + "} Called with text '" + text + "'");
        }

        bodyText = text.trim();

    }


    /**
     * Process the end of this element.
     *
     * @param namespace the namespace URI of the matching element, or an 
     *   empty string if the parser is not namespace aware or the element has
     *   no namespace
     * @param name the local name if the parser is namespace aware, or just 
     *   the element name otherwise
     *
     * @exception NoSuchMethodException if the bean does not
     *  have a writeable property of the specified name
     */
    @Override
    public void end(String namespace, String name) throws Exception {

        String property = propertyName;

        if (property == null) {
            // If we don't have a specific property name,
            // use the element name.
            property = name;
        }

        // Get a reference to the top object
        Object top = digester.peek();

        // log some debugging information
        if (digester.log.isDebugEnabled()) {
            digester.log.debug("[BeanPropertySetterRule]{" + digester.match +
                    "} Set " + top.getClass().getName() + " property " +
                               property + " with text " + bodyText);
        }

        // Force an exception if the property does not exist
        // (BeanUtils.setProperty() silently returns in this case)
        if (top instanceof DynaBean) {
            DynaProperty desc =
                ((DynaBean) top).getDynaClass().getDynaProperty(property);
            if (desc == null) {
                throw new NoSuchMethodException
                    ("Bean has no property named " + property);
            }
        } else /* this is a standard JavaBean */ {
            PropertyDescriptor desc =
                PropertyUtils.getPropertyDescriptor(top, property);
            if (desc == null) {
                throw new NoSuchMethodException
                    ("Bean has no property named " + property);
            }
        }

        // Set the property (with conversion as necessary)
        BeanUtils.setProperty(top, property, bodyText);

    }


    /**
     * Clean up after parsing is complete.
     */
    @Override
    public void finish() throws Exception {

        bodyText = null;

    }


    /**
     * Render a printable version of this Rule.
     */
    @Override
    public String toString() {

        StringBuffer sb = new StringBuffer("BeanPropertySetterRule[");
        sb.append("propertyName=");
        sb.append(propertyName);
        sb.append("]");
        return (sb.toString());

    }

}