Class PropertyUtilsBean

java.lang.Object
org.apache.commons.beanutils2.PropertyUtilsBean

public class PropertyUtilsBean extends Object
Utility methods for using Java Reflection APIs to facilitate generic property getter and setter operations on Java objects. Much of this code was originally included in BeanUtils, but has been separated because of the volume of code involved.

In general, the objects that are examined and modified using these methods are expected to conform to the property getter and setter method naming conventions described in the JavaBeans Specification (Version 1.0.1). No data type conversions are performed, and there are no usage of any PropertyEditor classes that have been registered, although a convenient way to access the registered classes themselves is included.

For the purposes of this class, five formats for referencing a particular property value of a bean are defined, with the default layout of an identifying String in parentheses. However the notation for these formats and how they are resolved is now (since BeanUtils 1.8.0) controlled by the configured Resolver implementation:

  • Simple (name) - The specified name identifies an individual property of a particular JavaBean. The name of the actual getter or setter method to be used is determined using standard JavaBeans introspection, so that (unless overridden by a BeanInfo class, a property named "xyz" will have a getter method named getXyz() or (for boolean properties only) isXyz(), and a setter method named setXyz().
  • Nested (name1.name2.name3) The first name element is used to select a property getter, as for simple references above. The object returned for this property is then consulted, using the same approach, for a property getter for a property named name2, and so on. The property value that is ultimately retrieved or modified is the one identified by the last name element.
  • Indexed (name[index]) - The underlying property value is assumed to be an array, or this JavaBean is assumed to have indexed property getter and setter methods. The appropriate (zero-relative) entry in the array is selected. List objects are now also supported for read/write. You simply need to define a getter that returns the List
  • Mapped (name(key)) - The JavaBean is assumed to have an property getter and setter methods with an additional attribute of type String.
  • Combined (name1.name2[index].name3(key)) - Combining mapped, nested, and indexed references is also supported.
Since:
1.7
See Also:
  • Constructor Details

  • Method Details

    • getInstance

      protected static PropertyUtilsBean getInstance()
      Gets the PropertyUtils bean instance.
      Returns:
      The PropertyUtils bean instance
    • addBeanIntrospector

      public void addBeanIntrospector(BeanIntrospector introspector)
      Adds a BeanIntrospector. This object is invoked when the property descriptors of a class need to be obtained.
      Parameters:
      introspector - the BeanIntrospector to be added (must not be null
      Throws:
      IllegalArgumentException - if the argument is null
      Since:
      1.9
    • clearDescriptors

      public void clearDescriptors()
      Clear any cached property descriptors information for all classes loaded by any class loaders. This is useful in cases where class loaders are thrown away to implement class reloading.
    • copyProperties

      Copy property values from the "origin" bean to the "destination" bean for all cases where the property names are the same (even though the actual getter and setter methods might have been customized via BeanInfo classes). No conversions are performed on the actual property values -- it is assumed that the values retrieved from the origin bean are assignment-compatible with the types expected by the destination bean.

      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 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.

      Note, that this method will not copy a List to a List, or an Object[] to an Object[]. It's specifically for copying JavaBean properties.

      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
      NoSuchMethodException - if an accessor method for this property cannot be found
    • describe

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

      FIXME - Does not account for mapped properties.

      Parameters:
      bean - Bean whose properties are to be extracted
      Returns:
      The set of properties for the bean
      Throws:
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean is null
      InvocationTargetException - if the property accessor method throws an exception
      NoSuchMethodException - if an accessor method for this property cannot be found
    • getIndexedProperty

      Gets the value of the specified indexed property of the specified bean, with no type conversions. 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. In addition to supporting the JavaBeans specification, this method has been extended to support List objects as well.
      Parameters:
      bean - Bean whose property is to be extracted
      name - propertyname[index] of the property value to be extracted
      Returns:
      the indexed property value
      Throws:
      IndexOutOfBoundsException - if the specified index is outside the valid range for the underlying array or List
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      InvocationTargetException - if the property accessor method throws an exception
      NoSuchMethodException - if an accessor method for this property cannot be found
    • getIndexedProperty

      Gets the value of the specified indexed property of the specified bean, with no type conversions. In addition to supporting the JavaBeans specification, this method has been extended to support List objects as well.
      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
      Returns:
      the indexed property value
      Throws:
      IndexOutOfBoundsException - if the specified index is outside the valid range for the underlying property
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      InvocationTargetException - if the property accessor method throws an exception
      NoSuchMethodException - if an accessor method for this property cannot be found
    • getMappedProperty

      Gets the value of the specified mapped property of the specified bean, with no type conversions. The key of the required value must be included (in brackets) as a suffix to the property name, or IllegalArgumentException will be thrown.
      Parameters:
      bean - Bean whose property is to be extracted
      name - propertyname(key) of the property value to be extracted
      Returns:
      the mapped property value
      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

      Gets the value of the specified mapped property of the specified bean, with no type conversions.
      Parameters:
      bean - Bean whose property is to be extracted
      name - Mapped property name of the property value to be extracted
      key - Key of the property value to be extracted
      Returns:
      the mapped property value
      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

      Gets the value of the (possibly nested) property of the specified name, for the specified bean, with no type conversions.
      Parameters:
      bean - Bean whose property is to be extracted
      name - Possibly nested name of the property to be extracted
      Returns:
      the nested property value
      Throws:
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      NestedNullException - 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

      Gets the value of the specified property of the specified bean, no matter which property reference format is used, with no type conversions.
      Parameters:
      bean - Bean whose property is to be extracted
      name - Possibly indexed and/or nested name of the property to be extracted
      Returns:
      the property value
      Throws:
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      InvocationTargetException - if the property accessor method throws an exception
      NoSuchMethodException - if an accessor method for this property cannot be found
    • getPropertyDescriptor

      Retrieve the property descriptor for the specified property of the specified bean, or return null if there is no such descriptor. This method resolves indexed and nested property references in the same manner as other methods in this class, except that if the last (or only) name element is indexed, the descriptor for the last resolved property itself is returned.

      FIXME - Does not work with DynaBeans.

      Note that for Java 8 and above, this method no longer return IndexedPropertyDescriptor for List-typed properties, only for properties typed as native array. (BEANUTILS-492).

      Parameters:
      bean - Bean for which a property descriptor is requested
      name - Possibly indexed and/or nested name of the property for which a property descriptor is requested
      Returns:
      the property descriptor
      Throws:
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      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
    • getPropertyDescriptors

      Retrieve the property descriptors for the specified class, introspecting and caching them the first time a particular bean class is encountered.

      FIXME - Does not work with DynaBeans.

      Parameters:
      beanClass - Bean class for which property descriptors are requested
      Returns:
      the property descriptors
      Throws:
      IllegalArgumentException - if beanClass is null
    • getPropertyDescriptors

      Retrieve the property descriptors for the specified bean, introspecting and caching them the first time a particular bean class is encountered.

      FIXME - Does not work with DynaBeans.

      Parameters:
      bean - Bean for which property descriptors are requested
      Returns:
      the property descriptors
      Throws:
      IllegalArgumentException - if bean is null
    • getPropertyEditorClass

      Return the Java Class repesenting the property editor class that has been registered for this property (if any). This method follows the same name resolution rules used by getPropertyDescriptor(), so if the last element of a name reference is indexed, the property editor for the underlying property's class is returned.

      Note that null will be returned if there is no property, or if there is no registered property editor class. Because this return value is ambiguous, you should determine the existence of the property itself by other means.

      FIXME - Does not work with DynaBeans.

      Parameters:
      bean - Bean for which a property descriptor is requested
      name - Possibly indexed and/or nested name of the property for which a property descriptor is requested
      Returns:
      the property editor class
      Throws:
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      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
    • getPropertyOfMapBean

      This method is called by getNestedProperty and setNestedProperty to define what it means to get a property from an object which implements Map. See setPropertyOfMapBean for more information.
      Parameters:
      bean - Map bean
      propertyName - The property name
      Returns:
      the property value
      Throws:
      IllegalArgumentException - when the propertyName is regarded as being invalid.
      IllegalAccessException - just in case subclasses override this method to try to access real getter methods and find permission is denied.
      InvocationTargetException - just in case subclasses override this method to try to access real getter methods, and find it throws an exception when invoked.
      NoSuchMethodException - just in case subclasses override this method to try to access real getter methods, and want to fail if no simple method is available.
      Since:
      1.8.0
    • getPropertyType

      Gets the Java Class representing the property type of the specified property, or null if there is no such property for the specified bean. This method follows the same name resolution rules used by getPropertyDescriptor(), so if the last element of a name reference is indexed, the type of the property itself will be returned. If the last (or only) element has no property with the specified name, null is returned.

      If the property is an indexed property (for example String[]), this method will return the type of the items within that array. Note that from Java 8 and newer, this method do not support such index types from items within an Collection, and will instead return the collection type (for example java.util.List) from the getter method.

      Parameters:
      bean - Bean for which a property descriptor is requested
      name - Possibly indexed and/or nested name of the property for which a property descriptor is requested
      Returns:
      The property type
      Throws:
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      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
    • getReadMethod

      public Method getReadMethod(Class<?> clazz, PropertyDescriptor descriptor)

      Return the property getter method for this property if accessible from given clazz (and if there is one at all); otherwise return null.

      FIXME - Does not work with DynaBeans.

      This fairly low-level method shouldn't be needed for most usecases. However, if you do have to implement something extra, you can improve consistency with the standard code (for example that of getProperty()) by calling this method instead of using descriptor.getReadMethod() directly.

      Parameters:
      clazz - The class of the read method will be invoked on
      descriptor - Property descriptor to return a getter for
      Returns:
      The read method
      Since:
      2.0.0
    • getReadMethod

      Return an accessible property getter method for this property, if there is one; otherwise return null.

      FIXME - Does not work with DynaBeans.

      Parameters:
      descriptor - Property descriptor to return a getter for
      Returns:
      The read method
    • getResolver

      Gets the configured Resolver implementation used by BeanUtils.

      The Resolver handles the property name expressions and the implementation in use effectively controls the dialect of the expression language that BeanUtils recognizes.

      DefaultResolver is the default implementation used.

      Returns:
      resolver The property expression resolver.
      Since:
      1.8.0
    • getSimpleProperty

      Gets the value of the specified simple property of the specified bean, with no type conversions.
      Parameters:
      bean - Bean whose property is to be extracted
      name - Name of the property to be extracted
      Returns:
      The property value
      Throws:
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      IllegalArgumentException - if the property name is nested or indexed
      InvocationTargetException - if the property accessor method throws an exception
      NoSuchMethodException - if an accessor method for this property cannot be found
    • getWriteMethod

      public Method getWriteMethod(Class<?> clazz, PropertyDescriptor descriptor)

      Return the property setter method for this property if accessible from given clazz (and if there is one at all); otherwise return null.

      FIXME - Does not work with DynaBeans.

      This fairly low-level method shouldn't be needed for most usecases. However, if you do have to implement something extra, you can improve consistency with the standard code (for example that of setProperty()) by calling this method instead of using descriptor.getWriteMethod() directly.

      Parameters:
      clazz - The class of the read method will be invoked on
      descriptor - Property descriptor to return a setter for
      Returns:
      The write method
      Since:
      1.9.1
    • getWriteMethod

      Return an accessible property setter method for this property, if there is one; otherwise return null.

      Note: This method does not work correctly with custom bean introspection under certain circumstances. It may return null even if a write method is defined for the property in question. Use getWriteMethod(Class, PropertyDescriptor) to be sure that the correct result is returned.

      FIXME - Does not work with DynaBeans.

      Parameters:
      descriptor - Property descriptor to return a setter for
      Returns:
      The write method
    • isReadable

      public boolean isReadable(Object bean, String name)
      Return true if the specified property name identifies a readable property on the specified bean; otherwise, return false.
      Parameters:
      bean - Bean to be examined (may be a DynaBean
      name - Property name to be evaluated
      Returns:
      true if the property is readable, otherwise false
      Throws:
      IllegalArgumentException - if bean or name</code> is <code>null
      Since:
      1.6
    • isWriteable

      public boolean isWriteable(Object bean, String name)
      Return true if the specified property name identifies a writable property on the specified bean; otherwise, return false.
      Parameters:
      bean - Bean to be examined (may be a DynaBean
      name - Property name to be evaluated
      Returns:
      true if the property is writable, otherwise false
      Throws:
      IllegalArgumentException - if bean or name</code> is <code>null
      Since:
      1.6
    • removeBeanIntrospector

      public boolean removeBeanIntrospector(BeanIntrospector introspector)
      Removes the specified BeanIntrospector.
      Parameters:
      introspector - the BeanIntrospector to be removed
      Returns:
      true if the BeanIntrospector existed and could be removed, false otherwise
      Since:
      1.9
    • resetBeanIntrospectors

      public final void resetBeanIntrospectors()
      Resets the BeanIntrospector objects registered at this instance. After this method was called, only the default BeanIntrospector is registered.
      Since:
      1.9
    • setIndexedProperty

      Sets the value of the specified indexed property of the specified bean, with no type conversions. In addition to supporting the JavaBeans specification, this method has been extended to support List objects as well.
      Parameters:
      bean - Bean whose property is to be set
      name - Simple property name of the property value to be set
      index - Index of the property value to be set
      value - Value to which the indexed property element is to be set
      Throws:
      IndexOutOfBoundsException - if the specified index is outside the valid range for the underlying property
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      InvocationTargetException - if the property accessor method throws an exception
      NoSuchMethodException - if an accessor method for this property cannot be found
    • setIndexedProperty

      Sets the value of the specified indexed property of the specified bean, with no type conversions. 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. In addition to supporting the JavaBeans specification, this method has been extended to support List objects as well.
      Parameters:
      bean - Bean whose property is to be modified
      name - propertyname[index] of the property value to be modified
      value - Value to which the specified property element should be set
      Throws:
      IndexOutOfBoundsException - if the specified index is outside the valid range for the underlying property
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      InvocationTargetException - if the property accessor method throws an exception
      NoSuchMethodException - if an accessor method for this property cannot be found
    • setMappedProperty

      Sets the value of the specified mapped property of the specified bean, with no type conversions. The key of the value to set must be included (in brackets) as a suffix to the property name, or IllegalArgumentException will be thrown.
      Parameters:
      bean - Bean whose property is to be set
      name - propertyname(key) of the property value to be set
      value - The property 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
      NoSuchMethodException - if an accessor method for this property cannot be found
    • setMappedProperty

      Sets the value of the specified mapped property of the specified bean, with no type conversions.
      Parameters:
      bean - Bean whose property is to be set
      name - Mapped property name of the property value to be set
      key - Key of the property value to be set
      value - The property 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
      NoSuchMethodException - if an accessor method for this property cannot be found
    • setNestedProperty

      Sets the value of the (possibly nested) property of the specified name, for the specified bean, with no type conversions.

      Example values for parameter "name" are:

      • "a" -- sets the value of property a of the specified bean
      • "a.b" -- gets the value of property a of the specified bean, then on that object sets the value of property b.
      • "a(key)" -- sets a value of mapped-property a on the specified bean. This effectively means bean.setA("key").
      • "a[3]" -- sets a value of indexed-property a on the specified bean. This effectively means bean.setA(3).
      Parameters:
      bean - Bean whose property is to be modified
      name - Possibly nested name of the property to be modified
      value - Value to which the property is to be set
      Throws:
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      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
    • setProperty

      Sets the value of the specified property of the specified bean, no matter which property reference format is used, with no type conversions.
      Parameters:
      bean - Bean whose property is to be modified
      name - Possibly indexed and/or nested name of the property to be modified
      value - Value to which this property is to be set
      Throws:
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      InvocationTargetException - if the property accessor method throws an exception
      NoSuchMethodException - if an accessor method for this property cannot be found
    • setPropertyOfMapBean

      This method is called by method setNestedProperty when the current bean is found to be a Map object, and defines how to deal with setting a property on a Map.

      The standard implementation here is to:

      • call bean.set(propertyName) for all propertyName values.
      • throw an IllegalArgumentException if the property specifier contains MAPPED_DELIM or INDEXED_DELIM, as Map entries are essentially simple properties; mapping and indexing operations do not make sense when accessing a map (even thought the returned object may be a Map or an Array).

      The default behavior of BeanUtils 1.7.1 or later is for assigning to "a.b" to mean a.put(b, obj) always. However the behavior of BeanUtils version 1.6.0, 1.6.1, 1.7.0 was for "a.b" to mean a.setB(obj) if such a method existed, and a.put(b, obj) otherwise. In version 1.5 it meant a.put(b, obj) always (ie the same as the behavior in the current version). In versions prior to 1.5 it meant a.setB(obj) always. [yes, this is all very unfortunate]

      Users who would like to customize the meaning of "a.b" in method setNestedProperty when a is a Map can create a custom subclass of this class and override this method to implement the behavior of their choice, such as restoring the pre-1.4 behavior of this class if they wish. When overriding this method, do not forget to deal with MAPPED_DELIM and INDEXED_DELIM characters in the propertyName.

      Note, however, that the recommended solution for objects that implement Map but want their simple properties to come first is for those objects to override their get/put methods to implement that behavior, and not to solve the problem by modifying the default behavior of the PropertyUtilsBean class by overriding this method.

      Parameters:
      bean - Map bean
      propertyName - The property name
      value - the property value
      Throws:
      IllegalArgumentException - when the propertyName is regarded as being invalid.
      IllegalAccessException - just in case subclasses override this method to try to access real setter methods and find permission is denied.
      InvocationTargetException - just in case subclasses override this method to try to access real setter methods, and find it throws an exception when invoked.
      NoSuchMethodException - just in case subclasses override this method to try to access real setter methods, and want to fail if no simple method is available.
      Since:
      1.8.0
    • setResolver

      public void setResolver(Resolver resolver)
      Configure the Resolver implementation used by BeanUtils.

      The Resolver handles the property name expressions and the implementation in use effectively controls the dialect of the expression language that BeanUtils recognizes.

      DefaultResolver is the default implementation used.

      Parameters:
      resolver - The property expression resolver.
      Since:
      1.8.0
    • setSimpleProperty

      Sets the value of the specified simple property of the specified bean, with no type conversions.
      Parameters:
      bean - Bean whose property is to be modified
      name - Name of the property to be modified
      value - Value to which the property should be set
      Throws:
      IllegalAccessException - if the caller does not have access to the property accessor method
      IllegalArgumentException - if bean or name is null
      IllegalArgumentException - if the property name is nested or indexed
      InvocationTargetException - if the property accessor method throws an exception
      NoSuchMethodException - if an accessor method for this property cannot be found