org.apache.commons.beanutils

Class BeanUtilsBean

public class BeanUtilsBean extends Object

JavaBean property population methods.

This class provides implementations for the utility methods in {@link BeanUtils}. Different instances can be used to isolate caches between classloaders and to vary the value converters registered.

Since: 1.7

Version: $Revision: 1.16 $ $Date: 2004/02/28 13:18:33 $

Author: Craig R. McClanahan Ralph Schaer Chris Audley Rey François Gregor Raýman

See Also: BeanUtils

Field Summary
static ContextClassLoaderLocalbeansByClassLoader
Contains BeanUtilsBean instances indexed by context classloader.
ConvertUtilsBeanconvertUtilsBean
Used to perform conversions between object types when setting properties
Loglog
Logging for this instance
PropertyUtilsBeanpropertyUtilsBean
Used to access properties
Constructor Summary
BeanUtilsBean()

Constructs an instance using new property and conversion instances.

BeanUtilsBean(ConvertUtilsBean convertUtilsBean, PropertyUtilsBean propertyUtilsBean)

Constructs an instance using given property and conversion instances.

Method Summary
ObjectcloneBean(Object bean)

Clone a bean based on the available property getters and setters, even if the bean class itself does not implement Cloneable.

Note: this method creates a shallow clone.

voidcopyProperties(Object dest, Object orig)

Copy property values from the origin bean to the destination bean for all cases where the property names are the same.

voidcopyProperty(Object bean, String name, Object value)

Copy the specified property value to the specified destination bean, performing any type conversion that is required.

Mapdescribe(Object bean)

Return the entire set of properties for which the specified bean provides a read method.

intfindLastNestedIndex(String expression)
String[]getArrayProperty(Object bean, String name)
Return the value of the specified array property of the specified bean, as a String array.
ConvertUtilsBeangetConvertUtils()
Gets the ConvertUtilsBean instance used to perform the conversions.
StringgetIndexedProperty(Object bean, String name)
Return the value of the specified indexed property of the specified bean, as a String.
StringgetIndexedProperty(Object bean, String name, int index)
Return the value of the specified indexed property of the specified bean, as a String.
static BeanUtilsBeangetInstance()
Gets the instance which provides the functionality for {@link BeanUtils}.
StringgetMappedProperty(Object bean, String name)
Return the value of the specified indexed property of the specified bean, as a String.
StringgetMappedProperty(Object bean, String name, String key)
Return the value of the specified mapped property of the specified bean, as a String.
StringgetNestedProperty(Object bean, String name)
Return the value of the (possibly nested) property of the specified name, for the specified bean, as a String.
StringgetProperty(Object bean, String name)
Return the value of the specified property of the specified bean, no matter which property reference format is used, as a String.
PropertyUtilsBeangetPropertyUtils()
Gets the PropertyUtilsBean instance used to access properties.
StringgetSimpleProperty(Object bean, String name)
Return the value of the specified simple property of the specified bean, converted to a String.
voidpopulate(Object bean, Map properties)

Populate the JavaBeans properties of the specified bean, based on the specified name/value pairs.

static voidsetInstance(BeanUtilsBean newInstance)
Sets the instance which provides the functionality for {@link BeanUtils}.
voidsetProperty(Object bean, String name, Object value)

Set the specified property value, performing type conversions as required to conform to the type of the destination property.

If the property is read only then the method returns without throwing an exception.

If null is passed into a property expecting a primitive value, then this will be converted as if it were a null string.

WARNING - The logic of this method is customized to meet the needs of populate(), and is probably not what you want for general property copying with type conversion.

Field Detail

beansByClassLoader

private static final ContextClassLoaderLocal beansByClassLoader
Contains BeanUtilsBean instances indexed by context classloader.

convertUtilsBean

private ConvertUtilsBean convertUtilsBean
Used to perform conversions between object types when setting properties

log

private Log log
Logging for this instance

propertyUtilsBean

private PropertyUtilsBean propertyUtilsBean
Used to access properties

Constructor Detail

BeanUtilsBean

public BeanUtilsBean()

Constructs an instance using new property and conversion instances.

BeanUtilsBean

public BeanUtilsBean(ConvertUtilsBean convertUtilsBean, PropertyUtilsBean propertyUtilsBean)

Constructs an instance using given property and conversion instances.

Parameters: convertUtilsBean use this ConvertUtilsBean to perform conversions from one object to another propertyUtilsBean use this PropertyUtilsBean to access properties

Method Detail

cloneBean

public Object cloneBean(Object bean)

Clone a bean based on the available property getters and setters, even if the bean class itself does not implement Cloneable.

Note: this method creates a shallow clone. In other words, any objects referred to by the bean are shared with the clone rather than being cloned in turn.

Parameters: bean Bean to be cloned

Throws: IllegalAccessException if the caller does not have access to the property accessor method InstantiationException if a new instance of the bean's class cannot be instantiated InvocationTargetException if the property accessor method throws an exception NoSuchMethodException if an accessor method for this property cannot be found

copyProperties

public void copyProperties(Object dest, Object orig)

Copy property values from the origin bean to the destination bean for all cases where the property names are the same. For each property, a conversion is attempted as necessary. All combinations of standard JavaBeans and DynaBeans as origin and destination are supported. Properties that exist in the origin bean, but do not exist in the destination bean (or are read-only in the destination bean) are silently ignored.

If the origin "bean" is actually a Map, it is assumed to contain String-valued simple property names as the keys, pointing at the corresponding property values that will be converted (if necessary) and set in the destination bean. Note that this method is intended to perform a "shallow copy" of the properties and so complex properties (for example, nested ones) will not be copied.

This method differs from populate(), which was primarily designed for populating JavaBeans from the map of request parameters retrieved on an HTTP request, is that no scalar->indexed or indexed->scalar manipulations are performed. If the origin property is indexed, the destination property must be also.

If you know that no type conversions are required, the copyProperties() method in {@link PropertyUtils} will execute faster than this method.

FIXME - Indexed and mapped properties that do not have getter and setter methods for the underlying array or Map are not copied by this method.

Parameters: dest Destination bean whose properties are modified orig Origin bean whose properties are retrieved

Throws: IllegalAccessException if the caller does not have access to the property accessor method IllegalArgumentException if the dest or orig argument is null InvocationTargetException if the property accessor method throws an exception

copyProperty

public void copyProperty(Object bean, String name, Object value)

Copy the specified property value to the specified destination bean, performing any type conversion that is required. If the specified bean does not have a property of the specified name, or the property is read only on the destination bean, return without doing anything. If you have custom destination property types, register {@link Converter}s for them by calling the register() method of {@link ConvertUtils}.

IMPLEMENTATION RESTRICTIONS:

Parameters: bean Bean on which setting is to be performed name Property name (can be nested/indexed/mapped/combo) value Value to be set

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception

describe

public Map describe(Object bean)

Return the entire set of properties for which the specified bean provides a read method. This map contains the to String converted property values for all properties for which a read method is provided (i.e. where the getReadMethod() returns non-null).

This map can be fed back to a call to BeanUtils.populate() to reconsitute the same set of properties, modulo differences for read-only and write-only properties, but only if there are no indexed properties.

Parameters: bean Bean whose properties are to be extracted

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception NoSuchMethodException if an accessor method for this property cannot be found

findLastNestedIndex

private int findLastNestedIndex(String expression)

getArrayProperty

public String[] getArrayProperty(Object bean, String name)
Return the value of the specified array property of the specified bean, as a String array.

Parameters: bean Bean whose property is to be extracted name Name of the property to be extracted

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception NoSuchMethodException if an accessor method for this property cannot be found

getConvertUtils

public ConvertUtilsBean getConvertUtils()
Gets the ConvertUtilsBean instance used to perform the conversions.

getIndexedProperty

public String getIndexedProperty(Object bean, String name)
Return the value of the specified indexed property of the specified bean, as a String. The zero-relative index of the required value must be included (in square brackets) as a suffix to the property name, or IllegalArgumentException will be thrown.

Parameters: bean Bean whose property is to be extracted name propertyname[index] of the property value to be extracted

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception NoSuchMethodException if an accessor method for this property cannot be found

getIndexedProperty

public String getIndexedProperty(Object bean, String name, int index)
Return the value of the specified indexed property of the specified bean, as a String. The index is specified as a method parameter and must *not* be included in the property name expression

Parameters: bean Bean whose property is to be extracted name Simple property name of the property value to be extracted index Index of the property value to be extracted

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception NoSuchMethodException if an accessor method for this property cannot be found

getInstance

public static BeanUtilsBean getInstance()
Gets the instance which provides the functionality for {@link BeanUtils}. This is a pseudo-singleton - an single instance is provided per (thread) context classloader. This mechanism provides isolation for web apps deployed in the same container.

getMappedProperty

public String getMappedProperty(Object bean, String name)
Return the value of the specified indexed property of the specified bean, as a String. The String-valued key of the required value must be included (in parentheses) as a suffix to the property name, or IllegalArgumentException will be thrown.

Parameters: bean Bean whose property is to be extracted name propertyname(index) of the property value to be extracted

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception NoSuchMethodException if an accessor method for this property cannot be found

getMappedProperty

public String getMappedProperty(Object bean, String name, String key)
Return the value of the specified mapped property of the specified bean, as a String. The key is specified as a method parameter and must *not* be included in the property name expression

Parameters: bean Bean whose property is to be extracted name Simple property name of the property value to be extracted key Lookup key of the property value to be extracted

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception NoSuchMethodException if an accessor method for this property cannot be found

getNestedProperty

public String getNestedProperty(Object bean, String name)
Return the value of the (possibly nested) property of the specified name, for the specified bean, as a String.

Parameters: bean Bean whose property is to be extracted name Possibly nested name of the property to be extracted

Throws: IllegalAccessException if the caller does not have access to the property accessor method IllegalArgumentException if a nested reference to a property returns null InvocationTargetException if the property accessor method throws an exception NoSuchMethodException if an accessor method for this property cannot be found

getProperty

public String getProperty(Object bean, String name)
Return the value of the specified property of the specified bean, no matter which property reference format is used, as a String.

Parameters: bean Bean whose property is to be extracted name Possibly indexed and/or nested name of the property to be extracted

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception NoSuchMethodException if an accessor method for this property cannot be found

getPropertyUtils

public PropertyUtilsBean getPropertyUtils()
Gets the PropertyUtilsBean instance used to access properties.

getSimpleProperty

public String getSimpleProperty(Object bean, String name)
Return the value of the specified simple property of the specified bean, converted to a String.

Parameters: bean Bean whose property is to be extracted name Name of the property to be extracted

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception NoSuchMethodException if an accessor method for this property cannot be found

populate

public void populate(Object bean, Map properties)

Populate the JavaBeans properties of the specified bean, based on the specified name/value pairs. This method uses Java reflection APIs to identify corresponding "property setter" method names, and deals with setter arguments of type String, boolean, int, long, float, and double. In addition, array setters for these types (or the corresponding primitive types) can also be identified.

The particular setter method to be called for each property is determined using the usual JavaBeans introspection mechanisms. Thus, you may identify custom setter methods using a BeanInfo class that is associated with the class of the bean itself. If no such BeanInfo class is available, the standard method name conversion ("set" plus the capitalized name of the property in question) is used.

NOTE: It is contrary to the JavaBeans Specification to have more than one setter method (with different argument signatures) for the same property.

WARNING - The logic of this method is customized for extracting String-based request parameters from an HTTP request. It is probably not what you want for general property copying with type conversion. For that purpose, check out the copyProperties() method instead.

Parameters: bean JavaBean whose properties are being populated properties Map keyed by property name, with the corresponding (String or String[]) value(s) to be set

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception

setInstance

public static void setInstance(BeanUtilsBean newInstance)
Sets the instance which provides the functionality for {@link BeanUtils}. This is a pseudo-singleton - an single instance is provided per (thread) context classloader. This mechanism provides isolation for web apps deployed in the same container.

setProperty

public void setProperty(Object bean, String name, Object value)

Set the specified property value, performing type conversions as required to conform to the type of the destination property.

If the property is read only then the method returns without throwing an exception.

If null is passed into a property expecting a primitive value, then this will be converted as if it were a null string.

WARNING - The logic of this method is customized to meet the needs of populate(), and is probably not what you want for general property copying with type conversion. For that purpose, check out the copyProperty() method instead.

WARNING - PLEASE do not modify the behavior of this method without consulting with the Struts developer community. There are some subtleties to its functionality that are not documented in the Javadoc description above, yet are vital to the way that Struts utilizes this method.

Parameters: bean Bean on which setting is to be performed name Property name (can be nested/indexed/mapped/combo) value Value to be set

Throws: IllegalAccessException if the caller does not have access to the property accessor method InvocationTargetException if the property accessor method throws an exception

Copyright (c) 2001-2004 - Apache Software Foundation