Commons Beanutils example source code file (Resolver.java)

This example Commons Beanutils source code file (Resolver.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 Beanutils tags/keywords

resolver, resolver, string, string

The Commons Beanutils Resolver.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.
 */
package org.apache.commons.beanutils.expression;

/**
 * Property Name Expression Resolver.
 * <p>
 * Methods such as PropertyUtilsBean's <code>setNestedProperty() method
 * use a <code>Resolver to process a property name
 * expression and resolve <i>nested, indexed and mapped
 * property names. The following code provides an example usage
 * demonstrating all the methods:
 *
 * <pre>
 *      // Iterate through a nested property expression
 *      while (resolver.hasNested(name)) {
 *
 *          // isolate a single property from a nested expresion
 *          String next = resolver.next(name);
 *
 *          // Process...
 *          String property = resolver.getProperty(next);
 *          if (resolver.isIndexed(next)) {
 *
 *              int index = resolver.getIndex(next);
 *              bean = getIndexedProperty(bean, property, index);
 *
 *          } else if (resolver.isMapped(next)) {
 *
 *              String key = resolver.getKey(next);
 *              bean = getMappedProperty(bean, property, key);
 *
 *          } else {
 *
 *              bean = getSimpleProperty(bean, property);
 *
 *          }
 *
 *          // remove the processed property from the expression
 *          name = resolver.remove(name);
 *      }
 * </pre>
 *
 * In order to create an implementation, it is important to understand how
 * BeanUtils/PropertyUtils uses the <code>resolver. The following are
 * the main methods that use it:
 * <ul>
 *   <li>{@link org.apache.commons.beanutils.PropertyUtilsBean}
 *   <ul>
 *       <li>{@link org.apache.commons.beanutils.PropertyUtilsBean#getIndexedProperty(Object, String)}
 *       <li>{@link org.apache.commons.beanutils.PropertyUtilsBean#getMappedProperty(Object, String)}
 *       <li>{@link org.apache.commons.beanutils.PropertyUtilsBean#getNestedProperty(Object, String)}
 *       <li>{@link org.apache.commons.beanutils.PropertyUtilsBean#getPropertyDescriptor(Object, String)}
 *       <li>{@link org.apache.commons.beanutils.PropertyUtilsBean#getSimpleProperty(Object, String)}
 *       <li>{@link org.apache.commons.beanutils.PropertyUtilsBean#setIndexedProperty(Object, String, Object)}
 *       <li>{@link org.apache.commons.beanutils.PropertyUtilsBean#setMappedProperty(Object, String, Object)}
 *       <li>{@link org.apache.commons.beanutils.PropertyUtilsBean#setNestedProperty(Object, String, Object)}
 *       <li>{@link org.apache.commons.beanutils.PropertyUtilsBean#setSimpleProperty(Object, String, Object)}
 *   </ul>
 *   <li>{@link org.apache.commons.beanutils.BeanUtilsBean}
 *   <ul>
 *       <li>{@link org.apache.commons.beanutils.BeanUtilsBean#copyProperty(Object, String, Object)}
 *       <li>{@link org.apache.commons.beanutils.BeanUtilsBean#setProperty(Object, String, Object)}
 *   </ul>
 *   <li>{@link org.apache.commons.beanutils.locale.LocaleBeanUtilsBean}
 *   <ul>
 *       <li>{@link org.apache.commons.beanutils.locale.LocaleBeanUtilsBean#setProperty(Object,
 *        String, Object, String)}</li>
 *   </ul>
 * </ul>
 *
 * @version $Revision: 555845 $ $Date: 2007-07-13 03:52:05 +0100 (Fri, 13 Jul 2007) $
 * @see org.apache.commons.beanutils.PropertyUtilsBean#setResolver(Resolver)
 * @since 1.8.0
 */
public interface Resolver {

    /**
     * Extract the index value from the property expression or -1.
     *
     * @param expression The property expression
     * @return The index value or -1 if the property is not indexed
     * @throws IllegalArgumentException If the indexed property is illegally
     * formed or has an invalid (non-numeric) value
     */
    int getIndex(String expression);

    /**
     * Extract the map key from the property expression or <code>null.
     *
     * @param expression The property expression
     * @return The index value
     * @throws IllegalArgumentException If the mapped property is illegally formed
     */
    String getKey(String expression);

    /**
     * Return the property name from the property expression.
     *
     * @param expression The property expression
     * @return The property name
     */
    String getProperty(String expression);

    /**
     * Indicates whether or not the expression
     * contains nested property expressions or not.
     *
     * @param expression The property expression
     * @return The next property expression
     */
    boolean hasNested(String expression);

    /**
     * Indicate whether the expression is for an indexed property or not.
     *
     * @param expression The property expression
     * @return <code>true if the expresion is indexed,
     *  otherwise <code>false
     */
    boolean isIndexed(String expression);

    /**
     * Indicate whether the expression is for a mapped property or not.
     *
     * @param expression The property expression
     * @return <code>true if the expresion is mapped,
     *  otherwise <code>false
     */
    boolean isMapped(String expression);

    /**
     * Extract the next property expression from the
     * current expression.
     *
     * @param expression The property expression
     * @return The next property expression
     */
    String next(String expression);

    /**
     * Remove the last property expresson from the
     * current expression.
     *
     * @param expression The property expression
     * @return The new expression value, with first property
     * expression removed - null if there are no more expressions
     */
    String remove(String expression);

}