Class LazyDynaMap

java.lang.Object
org.apache.commons.beanutils.LazyDynaBean
org.apache.commons.beanutils.LazyDynaMap
All Implemented Interfaces:
Serializable, DynaBean, DynaClass, MutableDynaClass

public class LazyDynaMap extends LazyDynaBean implements MutableDynaClass

Provides a light weight DynaBean facade to a Map with lazy map/list processing.

Its a light weight DynaBean implementation because there is no actual DynaClass associated with this DynaBean - in fact it implements the DynaClass interface itself providing pseudo DynaClass behaviour from the actual values stored in the Map.

As well providing rhe standard DynaBean access to the Map's properties this class also provides the usual Lazy behaviour:

  • Properties don't need to be pre-defined in a DynaClass
  • Indexed properties (Lists or Arrays) are automatically instantiated and grown so that they are large enough to cater for the index being set.
  • Mapped properties are automatically instantiated.

Restricted DynaClass

This class implements the MutableDynaClass interface. 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 Also:
  • Field Details

    • name

      protected String name
      The name of this DynaClass (analogous to the getName() method of java.lang.Class).
    • restricted

      protected boolean restricted
      Controls whether changes to this DynaClass's properties are allowed.
    • returnNull

      protected boolean returnNull

      Controls whether the getDynaProperty() method returns null if a property doesn't exist - or creates a new one.

      Default is false.

  • Constructor Details

    • LazyDynaMap

      public LazyDynaMap()
      Default Constructor.
    • LazyDynaMap

      public LazyDynaMap(String name)
      Construct a new LazyDynaMap with the specified name.
      Parameters:
      name - Name of this DynaBean class
    • LazyDynaMap

      public LazyDynaMap(Map<String,Object> values)
      Construct a new LazyDynaMap with the specified Map.
      Parameters:
      values - The Map backing this LazyDynaMap
    • LazyDynaMap

      public LazyDynaMap(String name, Map<String,Object> values)
      Construct a new LazyDynaMap with the specified name and Map.
      Parameters:
      name - Name of this DynaBean class
      values - The Map backing this LazyDynaMap
    • LazyDynaMap

      public LazyDynaMap(DynaProperty[] properties)
      Construct a new LazyDynaMap with the specified properties.
      Parameters:
      properties - Property descriptors for the supported properties
    • LazyDynaMap

      public LazyDynaMap(String name, DynaProperty[] properties)
      Construct a new LazyDynaMap with the specified name and properties.
      Parameters:
      name - Name of this DynaBean class
      properties - Property descriptors for the supported properties
    • LazyDynaMap

      public LazyDynaMap(DynaClass dynaClass)
      Construct a new LazyDynaMap based on an exisiting DynaClass
      Parameters:
      dynaClass - DynaClass to copy the name and properties from
  • Method Details

    • setMap

      public void setMap(Map<String,Object> values)
      Set the Map backing this DynaBean
      Parameters:
      values - The new Map of values
    • getMap

      public Map<String,Object> getMap()
      Return the underlying Map backing this DynaBean
      Overrides:
      getMap in class LazyDynaBean
      Returns:
      the underlying Map
      Since:
      1.8.0
    • set

      public void set(String name, Object value)
      Set the value of a simple property with the specified name.
      Specified by:
      set in interface DynaBean
      Overrides:
      set in class LazyDynaBean
      Parameters:
      name - Name of the property whose value is to be set
      value - Value to which this property is to be set
    • getName

      public String getName()
      Return the name of this DynaClass (analogous to the getName() method of java.lang.Class)
      Specified by:
      getName in interface DynaClass
      Returns:
      the name of the DynaClass
    • getDynaProperty

      public DynaProperty getDynaProperty(String name)

      Return a property descriptor for the specified property.

      If the property is not found and the returnNull indicator is true, this method always returns null.

      If the property is not found and the returnNull indicator is false a new property descriptor is created and returned (although its not actually added to the DynaClass's properties). This is the default beahviour.

      The reason for not returning a null property descriptor is that BeanUtils uses this method to check if a property exists before trying to set it - since these Map implementations automatically add any new properties when they are set, returning null from this method would defeat their purpose.

      Specified by:
      getDynaProperty in interface DynaClass
      Parameters:
      name - Name of the dynamic property for which a descriptor is requested
      Returns:
      The descriptor for the specified property
      Throws:
      IllegalArgumentException - if no property name is specified
    • getDynaProperties

      public DynaProperty[] getDynaProperties()

      Return an array of ProperyDescriptors for the properties currently defined in this DynaClass. If no properties are defined, a zero-length array will be returned.

      FIXME - Should we really be implementing getBeanInfo() instead, which returns property descriptors and a bunch of other stuff?

      Specified by:
      getDynaProperties in interface DynaClass
      Returns:
      the set of properties for this DynaClass
    • newInstance

      public DynaBean newInstance()
      Instantiate and return a new DynaBean instance, associated with this DynaClass.
      Specified by:
      newInstance in interface DynaClass
      Returns:
      A new DynaBean instance
    • isRestricted

      public boolean isRestricted()

      Is this DynaClass currently restricted.

      If restricted, no changes to the existing registration of property names, data types, readability, or writeability are allowed.

      Specified by:
      isRestricted in interface MutableDynaClass
      Returns:
      true if this Mutable DynaClass is restricted, otherwise false
    • setRestricted

      public void setRestricted(boolean restricted)

      Set whether this DynaClass is currently restricted.

      If restricted, no changes to the existing registration of property names, data types, readability, or writeability are allowed.

      Specified by:
      setRestricted in interface MutableDynaClass
      Parameters:
      restricted - The new restricted state
    • add

      public void add(String name)
      Add a new dynamic property with no restrictions on data type, readability, or writeability.
      Specified by:
      add in interface MutableDynaClass
      Parameters:
      name - Name of the new dynamic property
      Throws:
      IllegalArgumentException - if name is null
    • add

      public void add(String name, Class<?> type)
      Add a new dynamic property with the specified data type, but with no restrictions on readability or writeability.
      Specified by:
      add in interface MutableDynaClass
      Parameters:
      name - Name of the new dynamic property
      type - Data type of the new dynamic property (null for no restrictions)
      Throws:
      IllegalArgumentException - if name is null
      IllegalStateException - if this DynaClass is currently restricted, so no new properties can be added
    • add

      public void add(String name, Class<?> type, boolean readable, boolean writeable)

      Add a new dynamic property with the specified data type, readability, and writeability.

      N.B.Support for readable/writeable properties has not been implemented and this method always throws a UnsupportedOperationException.

      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 DynaProperty class (which they are not) and is the reason this method has not been implemented.

      Specified by:
      add in interface MutableDynaClass
      Parameters:
      name - Name of the new dynamic property
      type - Data type of the new dynamic property (null for no restrictions)
      readable - Set to true if this property value should be readable
      writeable - Set to true if this property value should be writeable
      Throws:
      UnsupportedOperationException - anytime this method is called
    • add

      protected void add(DynaProperty property)
      Add a new dynamic property.
      Parameters:
      property - Property the new dynamic property to add.
      Throws:
      IllegalArgumentException - if name is null
    • remove

      public void remove(String name)
      Remove the specified dynamic property, and any associated data type, readability, and writeability, from this dynamic class. NOTE - This does NOT cause any corresponding property values to be removed from DynaBean instances associated with this DynaClass.
      Specified by:
      remove in interface MutableDynaClass
      Parameters:
      name - Name of the dynamic property to remove
      Throws:
      IllegalArgumentException - if name is null
      IllegalStateException - if this DynaClass is currently restricted, so no properties can be removed
    • isReturnNull

      public boolean isReturnNull()
      Should this DynaClass return a null from the getDynaProperty(name) method if the property doesn't exist.
      Returns:
      true if a null DynaProperty should be returned if the property doesn't exist, otherwise false if a new DynaProperty should be created.
    • setReturnNull

      public void setReturnNull(boolean returnNull)
      Set whether this DynaClass should return a null from the getDynaProperty(name) method if the property doesn't exist.
      Parameters:
      returnNull - true if a null DynaProperty should be returned if the property doesn't exist, otherwise false if a new DynaProperty should be created.
    • isDynaProperty

      protected boolean isDynaProperty(String name)

      Indicate whether a property actually exists.

      N.B. Using getDynaProperty(name) == null doesn't work in this implementation because that method might return a DynaProperty if it doesn't exist (depending on the returnNull indicator).

      Overrides:
      isDynaProperty in class LazyDynaBean
      Parameters:
      name - Name of the dynamic property
      Returns:
      true if the property exists, otherwise false
      Throws:
      IllegalArgumentException - if no property name is specified