# AnnotationStrategy
Date: 2013-02-18

## org.simpleframework.xml.convert
Class AnnotationStrategy

    java.lang.Object
      org.simpleframework.xml.convert.AnnotationStrategy

All Implemented Interfaces:
  Strategy

    public class AnnotationStrategy

extends java.lang.Object
implements Strategy

The `AnnotationStrategy` object is used to intercept the serialization process and delegate to custom converters. This strategy uses the `Convert` annotation to specify the converter to use for serialization and deserialization. If there is no annotation present on the field or method representing the object instance to be serialized then this acts as a transparent proxy to an internal strategy.

By default the `TreeStrategy` is used to perform the normal serialization process should there be no annotation specifying a converter to use. However, any implementation can be used, including the `CycleStrategy`, which handles cycles in the object graph. To specify the internal strategy to use it can be provided in the constructor.

Author:
  Niall Gallagher
See Also:
  `TreeStrategy`

Constructor Summary
`AnnotationStrategy()` Constructor for the `AnnotationStrategy` object.
`AnnotationStrategy(Strategy strategy)` Constructor for the `AnnotationStrategy` object.

Method Summary
`Value` `read(Type type, NodeMap<InputNode> node, java.util.Map map)` This is used to read the `Value` which will be used to represent the deserialized object.
`boolean` `write(Type type, java.lang.Object value, NodeMap<OutputNode> node, java.util.Map map)` This is used to serialize a representation of the object value provided.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### AnnotationStrategy

    public AnnotationStrategy()

  Constructor for the `AnnotationStrategy` object. This creates a strategy that intercepts serialization on any annotated method or field. If no annotation exists then this delegates to an internal `TreeStrategy` object.

### AnnotationStrategy

    public AnnotationStrategy(Strategy strategy)

  Constructor for the `AnnotationStrategy` object. This creates a strategy that intercepts serialization on any annotated method or field. If no annotation exists then this will delegate to the `Strategy` provided.

  Parameters:
    `strategy` - the internal strategy to delegate to

Method Detail

### read

    public Value read(Type type,
                      NodeMap<InputNode> node,
                      java.util.Map map)
               throws java.lang.Exception

  This is used to read the `Value` which will be used to represent the deserialized object. If there is an annotation present then the value will contain an object instance. If it does not then it is up to the internal strategy to determine what the returned value contains.

  Specified by:
    `read` in interface `Strategy`
  Parameters:
    `type` - this is the type that represents a method or field
    `node` - this is the node representing the XML element
    `map` - this is the session map that contain variables
  Returns:
    the value representing the deserialized value
  Throws:
    `java.lang.Exception` - thrown if the class cannot be resolved

### write

    public boolean write(Type type,
                         java.lang.Object value,
                         NodeMap<OutputNode> node,
                         java.util.Map map)
                  throws java.lang.Exception

  This is used to serialize a representation of the object value provided. If there is a `Convert` annotation present on the provided type then this will use the converter specified to serialize a representation of the object. If however there is no annotation then this will delegate to the internal strategy. This returns true if the serialization has completed.

  Specified by:
    `write` in interface `Strategy`
  Parameters:
    `type` - this is the type that represents the field or method
    `value` - this is the object instance to be serialized
    `node` - this is the XML element to be serialized to
    `map` - this is the session map used by the serializer
  Returns:
    this returns true if it was serialized, false otherwise
  Throws:
    `java.lang.Exception` - thrown if the details cannot be set