- /*
- * Copyright 2004 The Apache Software Foundation.
- *
- * 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.apache.commons.beanutils;
-
- /**
- * <p>DynaClass which implements the <code>MutableDynaClass</code> interface.</p>
- *
- * <p>A <code>MutableDynaClass</code> is a specialized extension to <code>DynaClass</code>
- * that allows properties to be added or removed dynamically.</p>
- *
- * <p>This implementation has one slightly unusual default behaviour - calling
- * the <code>getDynaProperty(name)</code> method for a property which doesn't
- * exist returns a <code>DynaProperty</code> rather than <code>null</code>. The
- * reason for this is that <code>BeanUtils</code> calls this method to check if
- * a property exists before trying to set the value. This would defeat the object
- * of the <code>LazyDynaBean</code> which automatically adds missing properties
- * when any of its <code>set()</code> methods are called. For this reason the
- * <code>isDynaProperty(name)</code> method has been added to this implementation
- * in order to determine if a property actually exists. If the more <i>normal</i>
- * behaviour of returning <code>null</code> is required, then this can be achieved
- * by calling the <code>setReturnNull(true)</code>.</p>
- *
- * <p>The <code>add(name, type, readable, writable)</code> method is not implemented
- * and always throws an <code>UnsupportedOperationException</code>. I believe
- * this attributes need to be added to the <code>DynaProperty</code> class
- * in order to control read/write facilities.</p>
- *
- * @see LazyDynaBean
- * @author Niall Pemberton
- */
- public class LazyDynaClass extends BasicDynaClass implements MutableDynaClass {
-
- /**
- * Controls whether changes to this DynaClass's properties are allowed.
- */
- protected boolean restricted;
-
- /**
- * <p>Controls whether the <code>getDynaProperty()</code> method returns
- * null if a property doesn't exist - or creates a new one.</p>
- *
- * <p>Default is <code>false</code>.
- */
- protected boolean returnNull = false;
-
- /**
- * Construct a new LazyDynaClass with default parameters.
- */
- public LazyDynaClass() {
- this(null, (DynaProperty[])null);
- }
-
- /**
- * Construct a new LazyDynaClass with the specified name.
- *
- * @param name Name of this DynaBean class
- */
- public LazyDynaClass(String name) {
- this(name, (DynaProperty[])null);
- }
-
- /**
- * Construct a new LazyDynaClass with the specified name and DynaBean class.
- *
- * @param name Name of this DynaBean class
- * @param dynaBeanClass The implementation class for new instances
- */
- public LazyDynaClass(String name, Class dynaBeanClass) {
- this(name, dynaBeanClass, null);
- }
-
- /**
- * Construct a new LazyDynaClass with the specified name and properties.
- *
- * @param name Name of this DynaBean class
- * @param properties Property descriptors for the supported properties
- */
- public LazyDynaClass(String name, DynaProperty[] properties) {
- this(name, LazyDynaBean.class, properties);
- }
-
- /**
- * Construct a new LazyDynaClass with the specified name, DynaBean class and properties.
- *
- * @param name Name of this DynaBean class
- * @param dynaBeanClass The implementation class for new intances
- * @param properties Property descriptors for the supported properties
- */
- public LazyDynaClass(String name, Class dynaBeanClass, DynaProperty properties[]) {
- super(name, dynaBeanClass, properties);
- }
-
- /**
- * <p>Is this DynaClass currently restricted.</p>
- * <p>If restricted, no changes to the existing registration of
- * property names, data types, readability, or writeability are allowed.</p>
- */
- public boolean isRestricted() {
- return restricted;
- }
-
- /**
- * <p>Set whether this DynaClass is currently restricted.</p>
- * <p>If restricted, no changes to the existing registration of
- * property names, data types, readability, or writeability are allowed.</p>
- */
- public void setRestricted(boolean restricted) {
- this.restricted = restricted;
- }
-
- /**
- * Should this DynaClass return a <code>null</code> from
- * the <code>getDynaProperty(name)</code> method if the property
- * doesn't exist.
- */
- public boolean isReturnNull() {
- return returnNull;
- }
-
- /**
- * Set whether this DynaClass should return a <code>null</code> from
- * the <code>getDynaProperty(name)</code> method if the property
- * doesn't exist.
- */
- public void setReturnNull(boolean returnNull) {
- this.returnNull = returnNull;
- }
-
- /**
- * Add a new dynamic property with no restrictions on data type,
- * readability, or writeability.
- *
- * @param name Name of the new dynamic property
- *
- * @exception IllegalArgumentException if name is null
- * @exception IllegalStateException if this DynaClass is currently
- * restricted, so no new properties can be added
- */
- public void add(String name) {
- add(new DynaProperty(name));
- }
-
- /**
- * Add a new dynamic property with the specified data type, but with
- * no restrictions on readability or writeability.
- *
- * @param name Name of the new dynamic property
- * @param type Data type of the new dynamic property (null for no
- * restrictions)
- *
- * @exception IllegalArgumentException if name is null
- * @exception IllegalStateException if this DynaClass is currently
- * restricted, so no new properties can be added
- */
- public void add(String name, Class type) {
- add(new DynaProperty(name, type));
- }
-
- /**
- * <p>Add a new dynamic property with the specified data type, readability,
- * and writeability.</p>
- *
- * <p><strong>N.B.</strong>Support for readable/writeable properties has not been implemented
- * and this method always throws a <code>UnsupportedOperationException</code>.</p>
- *
- * <p>I'm not sure the intention of the original authors for this method, but it seems to
- * me that readable/writable should be attributes of the <code>DynaProperty</code> class
- * (which they are not) and is the reason this method has not been implemented.</p>
- *
- * @param name Name of the new dynamic property
- * @param type Data type of the new dynamic property (null for no
- * restrictions)
- * @param readable Set to <code>true</code> if this property value
- * should be readable
- * @param writeable Set to <code>true</code> if this property value
- * should be writeable
- *
- * @exception UnsupportedOperationException anytime this method is called
- */
- public void add(String name, Class type, boolean readable, boolean writeable) {
- throw new java.lang.UnsupportedOperationException("readable/writable properties not supported");
- }
-
- /**
- * Add a new dynamic property.
- *
- * @param property Property the new dynamic property to add.
- *
- * @exception IllegalArgumentException if name is null
- * @exception IllegalStateException if this DynaClass is currently
- * restricted, so no new properties can be added
- */
- protected void add(DynaProperty property) {
-
- if (property.getName() == null) {
- throw new IllegalArgumentException("Property name is missing.");
- }
-
- if (isRestricted()) {
- throw new IllegalStateException("DynaClass is currently restricted. No new properties can be added.");
- }
-
- // Check if property already exists
- if (propertiesMap.get(property.getName()) != null) {
- return;
- }
-
- // Create a new property array with the specified property
- DynaProperty[] oldProperties = getDynaProperties();
- DynaProperty[] newProperties = new DynaProperty[oldProperties.length+1];
- System.arraycopy(oldProperties, 0, newProperties, 0, oldProperties.length);
- newProperties[oldProperties.length] = property;
-
- // Update the properties
- setProperties(newProperties);
-
- }
-
- /**
- * Remove the specified dynamic property, and any associated data type,
- * readability, and writeability, from this dynamic class.
- * <strong>NOTE</strong> - This does <strong>NOT</strong> cause any
- * corresponding property values to be removed from DynaBean instances
- * associated with this DynaClass.
- *
- * @param name Name of the dynamic property to remove
- *
- * @exception IllegalArgumentException if name is null
- * @exception IllegalStateException if this DynaClass is currently
- * restricted, so no properties can be removed
- */
- public void remove(String name) {
-
- if (name == null) {
- throw new IllegalArgumentException("Property name is missing.");
- }
-
- if (isRestricted()) {
- throw new IllegalStateException("DynaClass is currently restricted. No properties can be removed.");
- }
-
- // Ignore if property doesn't exist
- if (propertiesMap.get(name) == null) {
- return;
- }
-
-
- // Create a new property array of without the specified property
- DynaProperty[] oldProperties = getDynaProperties();
- DynaProperty[] newProperties = new DynaProperty[oldProperties.length-1];
- int j = 0;
- for (int i = 0; i < oldProperties.length; i++) {
- if (!(name.equals(oldProperties[i].getName()))) {
- newProperties[j] = oldProperties[i];
- j++;
- }
- }
-
- // Update the properties
- setProperties(newProperties);
-
- }
-
- /**
- * <p>Return a property descriptor for the specified property.</p>
- *
- * <p>If the property is not found and the <code>returnNull</code> indicator is
- * <code>true</code>, this method always returns <code>null</code>.</p>
- *
- * <p>If the property is not found and the <code>returnNull</code> indicator is
- * <code>false</code> a new property descriptor is created and returned (although
- * its not actually added to the DynaClass's properties). This is the default
- * beahviour.</p>
- *
- * <p>The reason for not returning a <code>null</code> property descriptor is that
- * <code>BeanUtils</code> uses this method to check if a property exists
- * before trying to set it - since these <i>Lazy</i> implementations automatically
- * add any new properties when they are set, returning <code>null</code> from
- * this method would defeat their purpose.</p>
- *
- * @param name Name of the dynamic property for which a descriptor
- * is requested
- *
- * @exception IllegalArgumentException if no property name is specified
- */
- public DynaProperty getDynaProperty(String name) {
-
- if (name == null) {
- throw new IllegalArgumentException("Property name is missing.");
- }
-
- DynaProperty dynaProperty = (DynaProperty)propertiesMap.get(name);
-
- // If it doesn't exist and returnNull is false
- // create a new DynaProperty
- if (dynaProperty == null && !isReturnNull() && !isRestricted()) {
- dynaProperty = new DynaProperty(name);
- }
-
- return dynaProperty;
-
- }
-
- /**
- * <p>Indicate whether a property actually exists.</p>
- *
- * <p><strong>N.B.</strong> Using <code>getDynaProperty(name) == null</code>
- * doesn't work in this implementation because that method might
- * return a DynaProperty if it doesn't exist (depending on the
- * <code>returnNull</code> indicator).</p>
- *
- * @exception IllegalArgumentException if no property name is specified
- */
- public boolean isDynaProperty(String name) {
-
- if (name == null) {
- throw new IllegalArgumentException("Property name is missing.");
- }
-
- return propertiesMap.get(name) == null ? false : true;
-
- }
-
- }