org.springframework.expression.spel.support
Class ReflectivePropertyAccessor

java.lang.Object
  extended by org.springframework.expression.spel.support.ReflectivePropertyAccessor
All Implemented Interfaces:
PropertyAccessor

public class ReflectivePropertyAccessor
extends Object
implements PropertyAccessor

Simple PropertyAccessor that uses reflection to access properties for reading and writing. A property can be accessed if it is accessible as a field on the object or through a getter (if being read) or a setter (if being written).

Since:
3.0
Author:
Andy Clement, Juergen Hoeller

Field Summary
protected  Map<org.springframework.expression.spel.support.ReflectivePropertyAccessor.CacheKey,org.springframework.expression.spel.support.ReflectivePropertyAccessor.InvokerPair> readerCache
           
protected  Map<org.springframework.expression.spel.support.ReflectivePropertyAccessor.CacheKey,TypeDescriptor> typeDescriptorCache
           
protected  Map<org.springframework.expression.spel.support.ReflectivePropertyAccessor.CacheKey,Member> writerCache
           
 
Constructor Summary
ReflectivePropertyAccessor()
           
 
Method Summary
 boolean canRead(EvaluationContext context, Object target, String name)
          Called to determine if a resolver instance is able to access a specified property on a specified target object.
 boolean canWrite(EvaluationContext context, Object target, String name)
          Called to determine if a resolver instance is able to write to a specified property on a specified target object.
 PropertyAccessor createOptimalAccessor(EvaluationContext eContext, Object target, String name)
          Attempt to create an optimized property accessor tailored for a property of a particular name on a particular class.
protected  Field findField(String name, Class<?> clazz, boolean mustBeStatic)
          Find a field of a certain name on a specified class
protected  Method findGetterForProperty(String propertyName, Class<?> clazz, boolean mustBeStatic)
          Find a getter method for the specified property.
protected  Method findSetterForProperty(String propertyName, Class<?> clazz, boolean mustBeStatic)
          Find a setter method for the specified property.
 Class<?>[] getSpecificTargetClasses()
          Return an array of classes for which this resolver should be called.
 TypedValue read(EvaluationContext context, Object target, String name)
          Called to read a property from a specified target object
 void write(EvaluationContext context, Object target, String name, Object newValue)
          Called to write to a property on a specified target object.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

readerCache

protected final Map<org.springframework.expression.spel.support.ReflectivePropertyAccessor.CacheKey,org.springframework.expression.spel.support.ReflectivePropertyAccessor.InvokerPair> readerCache

writerCache

protected final Map<org.springframework.expression.spel.support.ReflectivePropertyAccessor.CacheKey,Member> writerCache

typeDescriptorCache

protected final Map<org.springframework.expression.spel.support.ReflectivePropertyAccessor.CacheKey,TypeDescriptor> typeDescriptorCache
Constructor Detail

ReflectivePropertyAccessor

public ReflectivePropertyAccessor()
Method Detail

getSpecificTargetClasses

public Class<?>[] getSpecificTargetClasses()
Description copied from interface: PropertyAccessor
Return an array of classes for which this resolver should be called. Returning null indicates this is a general resolver that can be called in an attempt to resolve a property on any type.

Specified by:
getSpecificTargetClasses in interface PropertyAccessor
Returns:
null which means this is a general purpose accessor

canRead

public boolean canRead(EvaluationContext context,
                       Object target,
                       String name)
                throws AccessException
Description copied from interface: PropertyAccessor
Called to determine if a resolver instance is able to access a specified property on a specified target object.

Specified by:
canRead in interface PropertyAccessor
Parameters:
context - the evaluation context in which the access is being attempted
target - the target object upon which the property is being accessed
name - the name of the property being accessed
Returns:
true if this resolver is able to read the property
Throws:
AccessException - if there is any problem determining whether the property can be read

read

public TypedValue read(EvaluationContext context,
                       Object target,
                       String name)
                throws AccessException
Description copied from interface: PropertyAccessor
Called to read a property from a specified target object

Specified by:
read in interface PropertyAccessor
Parameters:
context - the evaluation context in which the access is being attempted
target - the target object upon which the property is being accessed
name - the name of the property being accessed
Returns:
a TypedValue object wrapping the property value read and a type descriptor for it
Throws:
AccessException - if there is any problem accessing the property value

canWrite

public boolean canWrite(EvaluationContext context,
                        Object target,
                        String name)
                 throws AccessException
Description copied from interface: PropertyAccessor
Called to determine if a resolver instance is able to write to a specified property on a specified target object.

Specified by:
canWrite in interface PropertyAccessor
Parameters:
context - the evaluation context in which the access is being attempted
target - the target object upon which the property is being accessed
name - the name of the property being accessed
Returns:
true if this resolver is able to write to the property
Throws:
AccessException - if there is any problem determining whether the property can be written to

write

public void write(EvaluationContext context,
                  Object target,
                  String name,
                  Object newValue)
           throws AccessException
Description copied from interface: PropertyAccessor
Called to write to a property on a specified target object. Should only succeed if canWrite() also returns true.

Specified by:
write in interface PropertyAccessor
Parameters:
context - the evaluation context in which the access is being attempted
target - the target object upon which the property is being accessed
name - the name of the property being accessed
newValue - the new value for the property
Throws:
AccessException - if there is any problem writing to the property value

findGetterForProperty

protected Method findGetterForProperty(String propertyName,
                                       Class<?> clazz,
                                       boolean mustBeStatic)
Find a getter method for the specified property. A getter is defined as a method whose name start with the prefix 'get' and the rest of the name is the same as the property name (with the first character uppercased).


findSetterForProperty

protected Method findSetterForProperty(String propertyName,
                                       Class<?> clazz,
                                       boolean mustBeStatic)
Find a setter method for the specified property.


findField

protected Field findField(String name,
                          Class<?> clazz,
                          boolean mustBeStatic)
Find a field of a certain name on a specified class


createOptimalAccessor

public PropertyAccessor createOptimalAccessor(EvaluationContext eContext,
                                              Object target,
                                              String name)
Attempt to create an optimized property accessor tailored for a property of a particular name on a particular class. The general ReflectivePropertyAccessor will always work but is not optimal due to the need to lookup which reflective member (method/field) to use each time read() is called. This method will just return the ReflectivePropertyAccessor instance if it is unable to build something more optimal.