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/*
 * 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;

import java.io.Serializable;
import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * 

DynaBean which automatically adds properties to the DynaClass * and provides Lazy List and Lazy Map features.

* *

DynaBeans deal with three types of properties - simple, indexed and mapped and * have the following get() and set() methods for * each of these types:

*
    *
  • Simple property methods - get(name) and * set(name, value)
  • *
  • Indexed property methods - get(name, index) and * set(name, index, value)
  • *
  • Mapped property methods - get(name, key) and * set(name, key, value)
  • *
* *

Getting Property Values

*

Calling any of the get() methods, for a property which * doesn't exist, returns null in this implementation.

* *

Setting Simple Properties

*

The LazyDynaBean will automatically add a property to the DynaClass * if it doesn't exist when the set(name, value) method is called.

* * DynaBean myBean = new LazyDynaBean();
* myBean.set("myProperty", "myValue");
* *

Setting Indexed Properties

*

If the property doesn't exist, the LazyDynaBean will automatically add * a property with an ArrayList type to the DynaClass when * the set(name, index, value) method is called. * It will also instantiate a new ArrayList and automatically grow * the List so that it is big enough to accomodate the index being set. * ArrayList is the default indexed property that LazyDynaBean uses but * this can be easily changed by overriding the defaultIndexedProperty(name) * method.

* * DynaBean myBean = new LazyDynaBean();
* myBean.set("myIndexedProperty", 0, "myValue1");
* myBean.set("myIndexedProperty", 1, "myValue2");
* *

If the indexed property does exist in the DynaClass but is set to * null in the LazyDynaBean, then it will instantiate a * new List or Array as specified by the property's type * in the DynaClass and automatically grow the List * or Array so that it is big enough to accomodate the index being set.

* * DynaBean myBean = new LazyDynaBean();
* MutableDynaClass myClass = (MutableDynaClass)myBean.getDynaClass();
* myClass.add("myIndexedProperty", int[].class);
* myBean.set("myIndexedProperty", 0, new Integer(10));
* myBean.set("myIndexedProperty", 1, new Integer(20));
* *

Setting Mapped Properties

*

If the property doesn't exist, the LazyDynaBean will automatically add * a property with a HashMap type to the DynaClass and * instantiate a new HashMap in the DynaBean when the * set(name, key, value) method is called. HashMap is the default * mapped property that LazyDynaBean uses but this can be easily changed by overriding * the defaultMappedProperty(name) method.

* * DynaBean myBean = new LazyDynaBean();
* myBean.set("myMappedProperty", "myKey", "myValue");
* *

If the mapped property does exist in the DynaClass but is set to * null in the LazyDynaBean, then it will instantiate a * new Map as specified by the property's type in the DynaClass.

* * DynaBean myBean = new LazyDynaBean();
* MutableDynaClass myClass = (MutableDynaClass)myBean.getDynaClass();
* myClass.add("myMappedProperty", TreeMap.class);
* myBean.set("myMappedProperty", "myKey", "myValue");
* *

Restricted DynaClass

*

MutableDynaClass have a facility to restrict the DynaClass * so that its properties cannot be modified. If the MutableDynaClass is * restricted then calling any of the set() methods for a property which * doesn't exist will result in a IllegalArgumentException being thrown.

* * @version $Id$ * @see LazyDynaClass */ public class LazyDynaBean implements DynaBean, Serializable { /** * Commons Logging */ private transient Log logger = LogFactory.getLog(LazyDynaBean.class); /** BigInteger Zero */ protected static final BigInteger BigInteger_ZERO = new BigInteger("0"); /** BigDecimal Zero */ protected static final BigDecimal BigDecimal_ZERO = new BigDecimal("0"); /** Character Space */ protected static final Character Character_SPACE = new Character(' '); /** Byte Zero */ protected static final Byte Byte_ZERO = new Byte((byte)0); /** Short Zero */ protected static final Short Short_ZERO = new Short((short)0); /** Integer Zero */ protected static final Integer Integer_ZERO = new Integer(0); /** Long Zero */ protected static final Long Long_ZERO = new Long(0); /** Float Zero */ protected static final Float Float_ZERO = new Float((byte)0); /** Double Zero */ protected static final Double Double_ZERO = new Double((byte)0); /** * The MutableDynaClass "base class" that this DynaBean * is associated with. */ protected Map values; /** Map decorator for this DynaBean */ private transient Map mapDecorator; /** * The MutableDynaClass "base class" that this DynaBean * is associated with. */ protected MutableDynaClass dynaClass; // ------------------- Constructors ---------------------------------- /** * Construct a new LazyDynaBean with a LazyDynaClass instance. */ public LazyDynaBean() { this(new LazyDynaClass()); } /** * Construct a new LazyDynaBean with a LazyDynaClass instance. * * @param name Name of this DynaBean class */ public LazyDynaBean(final String name) { this(new LazyDynaClass(name)); } /** * Construct a new DynaBean associated with the specified * DynaClass instance - if its not a MutableDynaClass * then a new LazyDynaClass is created and the properties copied. * * @param dynaClass The DynaClass we are associated with */ public LazyDynaBean(final DynaClass dynaClass) { values = newMap(); if (dynaClass instanceof MutableDynaClass) { this.dynaClass = (MutableDynaClass)dynaClass; } else { this.dynaClass = new LazyDynaClass(dynaClass.getName(), dynaClass.getDynaProperties()); } } // ------------------- Public Methods ---------------------------------- /** * Return a Map representation of this DynaBean. *

* This, for example, could be used in JSTL in the following way to access * a DynaBean's fooProperty: *
  • ${myDynaBean.map.fooProperty}
* * @return a Map representation of this DynaBean */ public Map getMap() { // cache the Map if (mapDecorator == null) { mapDecorator = new DynaBeanPropertyMapDecorator(this); } return mapDecorator; } /** *

Return the size of an indexed or mapped property.

* * @param name Name of the property * @return The indexed or mapped property size * @throws IllegalArgumentException if no property name is specified */ public int size(final String name) { if (name == null) { throw new IllegalArgumentException("No property name specified"); } final Object value = values.get(name); if (value == null) { return 0; } if (value instanceof Map) { return ((Map)value).size(); } if (value instanceof List) { return ((List)value).size(); } if ((value.getClass().isArray())) { return Array.getLength(value); } return 0; } // ------------------- DynaBean Methods ---------------------------------- /** * Does the specified mapped property contain a value for the specified * key value? * * @param name Name of the property to check * @param key Name of the key to check * @return true if the mapped property contains a value for * the specified key, otherwise false * * @throws IllegalArgumentException if no property name is specified */ public boolean contains(final String name, final String key) { if (name == null) { throw new IllegalArgumentException("No property name specified"); } final Object value = values.get(name); if (value == null) { return false; } if (value instanceof Map) { return (((Map) value).containsKey(key)); } return false; } /** *

Return the value of a simple property with the specified name.

* *

N.B. Returns null if there is no property * of the specified name.

* * @param name Name of the property whose value is to be retrieved. * @return The property's value * @throws IllegalArgumentException if no property name is specified */ public Object get(final String name) { if (name == null) { throw new IllegalArgumentException("No property name specified"); } // Value found Object value = values.get(name); if (value != null) { return value; } // Property doesn't exist if (!isDynaProperty(name)) { return null; } // Property doesn't exist value = createProperty(name, dynaClass.getDynaProperty(name).getType()); if (value != null) { set(name, value); } return value; } /** *

Return the value of an indexed property with the specified name.

* *

N.B. Returns null if there is no 'indexed' * property of the specified name.

* * @param name Name of the property whose value is to be retrieved * @param index Index of the value to be retrieved * @return The indexed property's value * * @throws IllegalArgumentException if the specified property * exists, but is not indexed * @throws IndexOutOfBoundsException if the specified index * is outside the range of the underlying property */ public Object get(final String name, final int index) { // If its not a property, then create default indexed property if (!isDynaProperty(name)) { set(name, defaultIndexedProperty(name)); } // Get the indexed property Object indexedProperty = get(name); // Check that the property is indexed if (!dynaClass.getDynaProperty(name).isIndexed()) { throw new IllegalArgumentException ("Non-indexed property for '" + name + "[" + index + "]' " + dynaClass.getDynaProperty(name).getName()); } // Grow indexed property to appropriate size indexedProperty = growIndexedProperty(name, indexedProperty, index); // Return the indexed value if (indexedProperty.getClass().isArray()) { return Array.get(indexedProperty, index); } else if (indexedProperty instanceof List) { return ((List)indexedProperty).get(index); } else { throw new IllegalArgumentException ("Non-indexed property for '" + name + "[" + index + "]' " + indexedProperty.getClass().getName()); } } /** *

Return the value of a mapped property with the specified name.

* *

N.B. Returns null if there is no 'mapped' * property of the specified name.

* * @param name Name of the property whose value is to be retrieved * @param key Key of the value to be retrieved * @return The mapped property's value * * @throws IllegalArgumentException if the specified property * exists, but is not mapped */ public Object get(final String name, final String key) { // If its not a property, then create default mapped property if (!isDynaProperty(name)) { set(name, defaultMappedProperty(name)); } // Get the mapped property final Object mappedProperty = get(name); // Check that the property is mapped if (!dynaClass.getDynaProperty(name).isMapped()) { throw new IllegalArgumentException ("Non-mapped property for '" + name + "(" + key + ")' " + dynaClass.getDynaProperty(name).getType().getName()); } // Get the value from the Map if (mappedProperty instanceof Map) { return (((Map) mappedProperty).get(key)); } else { throw new IllegalArgumentException ("Non-mapped property for '" + name + "(" + key + ")'" + mappedProperty.getClass().getName()); } } /** * Return the DynaClass instance that describes the set of * properties available for this DynaBean. * * @return The associated DynaClass */ public DynaClass getDynaClass() { return dynaClass; } /** * Remove any existing value for the specified key on the * specified mapped property. * * @param name Name of the property for which a value is to * be removed * @param key Key of the value to be removed * * @throws IllegalArgumentException if there is no property * of the specified name */ public void remove(final String name, final String key) { if (name == null) { throw new IllegalArgumentException("No property name specified"); } final Object value = values.get(name); if (value == null) { return; } if (value instanceof Map) { ((Map) value).remove(key); } else { throw new IllegalArgumentException ("Non-mapped property for '" + name + "(" + key + ")'" + value.getClass().getName()); } } /** * Set the value of a simple property with the specified name. * * @param name Name of the property whose value is to be set * @param value Value to which this property is to be set * * @throws IllegalArgumentException if this is not an existing property * name for our DynaClass and the MutableDynaClass is restricted * @throws ConversionException if the specified value cannot be * converted to the type required for this property * @throws NullPointerException if an attempt is made to set a * primitive property to null */ public void set(final String name, final Object value) { // If the property doesn't exist, then add it if (!isDynaProperty(name)) { if (dynaClass.isRestricted()) { throw new IllegalArgumentException ("Invalid property name '" + name + "' (DynaClass is restricted)"); } if (value == null) { dynaClass.add(name); } else { dynaClass.add(name, value.getClass()); } } final DynaProperty descriptor = dynaClass.getDynaProperty(name); if (value == null) { if (descriptor.getType().isPrimitive()) { throw new NullPointerException ("Primitive value for '" + name + "'"); } } else if (!isAssignable(descriptor.getType(), value.getClass())) { throw new ConversionException ("Cannot assign value of type '" + value.getClass().getName() + "' to property '" + name + "' of type '" + descriptor.getType().getName() + "'"); } // Set the property's value values.put(name, value); } /** * Set the value of an indexed property with the specified name. * * @param name Name of the property whose value is to be set * @param index Index of the property to be set * @param value Value to which this property is to be set * * @throws ConversionException if the specified value cannot be * converted to the type required for this property * @throws IllegalArgumentException if there is no property * of the specified name * @throws IllegalArgumentException if the specified property * exists, but is not indexed * @throws IndexOutOfBoundsException if the specified index * is outside the range of the underlying property */ public void set(final String name, final int index, final Object value) { // If its not a property, then create default indexed property if (!isDynaProperty(name)) { set(name, defaultIndexedProperty(name)); } // Get the indexed property Object indexedProperty = get(name); // Check that the property is indexed if (!dynaClass.getDynaProperty(name).isIndexed()) { throw new IllegalArgumentException ("Non-indexed property for '" + name + "[" + index + "]'" + dynaClass.getDynaProperty(name).getType().getName()); } // Grow indexed property to appropriate size indexedProperty = growIndexedProperty(name, indexedProperty, index); // Set the value in an array if (indexedProperty.getClass().isArray()) { Array.set(indexedProperty, index, value); } else if (indexedProperty instanceof List) { @SuppressWarnings("unchecked") final // Indexed properties are stored in a List List values = (List) indexedProperty; values.set(index, value); } else { throw new IllegalArgumentException ("Non-indexed property for '" + name + "[" + index + "]' " + indexedProperty.getClass().getName()); } } /** * Set the value of a mapped property with the specified name. * * @param name Name of the property whose value is to be set * @param key Key of the property to be set * @param value Value to which this property is to be set * * @throws ConversionException if the specified value cannot be * converted to the type required for this property * @throws IllegalArgumentException if there is no property * of the specified name * @throws IllegalArgumentException if the specified property * exists, but is not mapped */ public void set(final String name, final String key, final Object value) { // If the 'mapped' property doesn't exist, then add it if (!isDynaProperty(name)) { set(name, defaultMappedProperty(name)); } // Get the mapped property final Object mappedProperty = get(name); // Check that the property is mapped if (!dynaClass.getDynaProperty(name).isMapped()) { throw new IllegalArgumentException ("Non-mapped property for '" + name + "(" + key + ")'" + dynaClass.getDynaProperty(name).getType().getName()); } // Set the value in the Map @SuppressWarnings("unchecked") final // mapped properties are stored in a Map Map valuesMap = (Map) mappedProperty; valuesMap.put(key, value); } // ------------------- protected Methods ---------------------------------- /** * Grow the size of an indexed property * @param name The name of the property * @param indexedProperty The current property value * @param index The indexed value to grow the property to (i.e. one less than * the required size) * @return The new property value (grown to the appropriate size) */ protected Object growIndexedProperty(final String name, Object indexedProperty, final int index) { // Grow a List to the appropriate size if (indexedProperty instanceof List) { @SuppressWarnings("unchecked") final // Indexed properties are stored as List List list = (List)indexedProperty; while (index >= list.size()) { final Class contentType = getDynaClass().getDynaProperty(name).getContentType(); Object value = null; if (contentType != null) { value = createProperty(name+"["+list.size()+"]", contentType); } list.add(value); } } // Grow an Array to the appropriate size if ((indexedProperty.getClass().isArray())) { final int length = Array.getLength(indexedProperty); if (index >= length) { final Class componentType = indexedProperty.getClass().getComponentType(); final Object newArray = Array.newInstance(componentType, (index + 1)); System.arraycopy(indexedProperty, 0, newArray, 0, length); indexedProperty = newArray; set(name, indexedProperty); final int newLength = Array.getLength(indexedProperty); for (int i = length; i < newLength; i++) { Array.set(indexedProperty, i, createProperty(name+"["+i+"]", componentType)); } } } return indexedProperty; } /** * Create a new Instance of a Property * @param name The name of the property * @param type The class of the property * @return The new value */ protected Object createProperty(final String name, final Class type) { if (type == null) { return null; } // Create Lists, arrays or DynaBeans if (type.isArray() || List.class.isAssignableFrom(type)) { return createIndexedProperty(name, type); } if (Map.class.isAssignableFrom(type)) { return createMappedProperty(name, type); } if (DynaBean.class.isAssignableFrom(type)) { return createDynaBeanProperty(name, type); } if (type.isPrimitive()) { return createPrimitiveProperty(name, type); } if (Number.class.isAssignableFrom(type)) { return createNumberProperty(name, type); } return createOtherProperty(name, type); } /** * Create a new Instance of an 'Indexed' Property * @param name The name of the property * @param type The class of the property * @return The new value */ protected Object createIndexedProperty(final String name, final Class type) { // Create the indexed object Object indexedProperty = null; if (type == null) { indexedProperty = defaultIndexedProperty(name); } else if (type.isArray()) { indexedProperty = Array.newInstance(type.getComponentType(), 0); } else if (List.class.isAssignableFrom(type)) { if (type.isInterface()) { indexedProperty = defaultIndexedProperty(name); } else { try { indexedProperty = type.newInstance(); } catch (final Exception ex) { throw new IllegalArgumentException ("Error instantiating indexed property of type '" + type.getName() + "' for '" + name + "' " + ex); } } } else { throw new IllegalArgumentException ("Non-indexed property of type '" + type.getName() + "' for '" + name + "'"); } return indexedProperty; } /** * Create a new Instance of a 'Mapped' Property * @param name The name of the property * @param type The class of the property * @return The new value */ protected Object createMappedProperty(final String name, final Class type) { // Create the mapped object Object mappedProperty = null; if (type == null) { mappedProperty = defaultMappedProperty(name); } else if (type.isInterface()) { mappedProperty = defaultMappedProperty(name); } else if (Map.class.isAssignableFrom(type)) { try { mappedProperty = type.newInstance(); } catch (final Exception ex) { throw new IllegalArgumentException ("Error instantiating mapped property of type '" + type.getName() + "' for '" + name + "' " + ex); } } else { throw new IllegalArgumentException ("Non-mapped property of type '" + type.getName() + "' for '" + name + "'"); } return mappedProperty; } /** * Create a new Instance of a 'DynaBean' Property. * @param name The name of the property * @param type The class of the property * @return The new value */ protected Object createDynaBeanProperty(final String name, final Class type) { try { return type.newInstance(); } catch (final Exception ex) { if (logger().isWarnEnabled()) { logger().warn("Error instantiating DynaBean property of type '" + type.getName() + "' for '" + name + "' " + ex); } return null; } } /** * Create a new Instance of a 'Primitive' Property. * @param name The name of the property * @param type The class of the property * @return The new value */ protected Object createPrimitiveProperty(final String name, final Class type) { if (type == Boolean.TYPE) { return Boolean.FALSE; } else if (type == Integer.TYPE) { return Integer_ZERO; } else if (type == Long.TYPE) { return Long_ZERO; } else if (type == Double.TYPE) { return Double_ZERO; } else if (type == Float.TYPE) { return Float_ZERO; } else if (type == Byte.TYPE) { return Byte_ZERO; } else if (type == Short.TYPE) { return Short_ZERO; } else if (type == Character.TYPE) { return Character_SPACE; } else { return null; } } /** * Create a new Instance of a java.lang.Number Property. * @param name The name of the property * @param type The class of the property * @return The new value */ protected Object createNumberProperty(final String name, final Class type) { return null; } /** * Create a new Instance of other Property types * @param name The name of the property * @param type The class of the property * @return The new value */ protected Object createOtherProperty(final String name, final Class type) { if (type == Object.class || type == String.class || type == Boolean.class || type == Character.class || Date.class.isAssignableFrom(type)) { return null; } try { return type.newInstance(); } catch (final Exception ex) { if (logger().isWarnEnabled()) { logger().warn("Error instantiating property of type '" + type.getName() + "' for '" + name + "' " + ex); } return null; } } /** *

Creates a new ArrayList for an 'indexed' property * which doesn't exist.

* *

This method should be overridden if an alternative List * or Array implementation is required for 'indexed' properties.

* * @param name Name of the 'indexed property. * @return The default value for an indexed property (java.util.ArrayList) */ protected Object defaultIndexedProperty(final String name) { return new ArrayList(); } /** *

Creates a new HashMap for a 'mapped' property * which doesn't exist.

* *

This method can be overridden if an alternative Map * implementation is required for 'mapped' properties.

* * @param name Name of the 'mapped property. * @return The default value for a mapped property (java.util.HashMap) */ protected Map defaultMappedProperty(final String name) { return new HashMap(); } /** * Indicates if there is a property with the specified name. * @param name The name of the property to check * @return true if there is a property of the * specified name, otherwise false */ protected boolean isDynaProperty(final String name) { if (name == null) { throw new IllegalArgumentException("No property name specified"); } // Handle LazyDynaClasses if (dynaClass instanceof LazyDynaClass) { return ((LazyDynaClass)dynaClass).isDynaProperty(name); } // Handle other MutableDynaClass return dynaClass.getDynaProperty(name) == null ? false : true; } /** * Is an object of the source class assignable to the destination class? * * @param dest Destination class * @param source Source class * @return true if the source class is assignable to the * destination class, otherwise false */ protected boolean isAssignable(final Class dest, final Class source) { if (dest.isAssignableFrom(source) || ((dest == Boolean.TYPE) && (source == Boolean.class)) || ((dest == Byte.TYPE) && (source == Byte.class)) || ((dest == Character.TYPE) && (source == Character.class)) || ((dest == Double.TYPE) && (source == Double.class)) || ((dest == Float.TYPE) && (source == Float.class)) || ((dest == Integer.TYPE) && (source == Integer.class)) || ((dest == Long.TYPE) && (source == Long.class)) || ((dest == Short.TYPE) && (source == Short.class))) { return (true); } else { return (false); } } /** *

Creates a new instance of the Map.

* @return a new Map instance */ protected Map newMap() { return new HashMap(); } /** *

Returns the Log. */ private Log logger() { if (logger == null) { logger = LogFactory.getLog(LazyDynaBean.class); } return logger; } }