java.beans
class Encoder

java.lang.Object java.beans.Encoder

Direct Known Subclasses:

XMLEncoder

public class Encoder
extends Object

An Encoder is a class which can be used to create files or streams that encode the state of a collection of JavaBeans in terms of their public APIs. The Encoder, in conjunction with its persistence delegates, is responsible for breaking the object graph down into a series of Statementss and Expressions which can be used to create it. A subclass typically provides a syntax for these expressions using some human readable form - like Java source code or XML.

Encoder

public Encoder()

get

public Object get(Object oldInstance)

Returns a tentative value for oldInstance in the environment created by this stream. A persistence delegate can use its mutatesTo method to determine whether this value may be initialized to form the equivalent object at the output or whether a new object must be instantiated afresh. If the stream has not yet seen this value, null is returned.

Parameters:

oldInstance - The instance to be looked up.

Returns:

The object, null if the object has not been seen before.

getExceptionListener

public ExceptionListener getExceptionListener()

Gets the exception handler for this stream.

Returns:

The exception handler for this stream; Will return the default exception listener if this has not explicitly been set.

getPersistenceDelegate

public PersistenceDelegate getPersistenceDelegate(Class type)

Returns the persistence delegate for the given type. The persistence delegate is calculated by applying the following of rules in order:

• If the type is an array, an internal persistence delegate is returned which will instantiate an array of the appropriate type and length, initializing each of its elements as if they are properties.
• If the type is a proxy, an internal persistence delegate is returned which will instantiate a new proxy instance using the static "newProxyInstance" method defined in the Proxy class.
• If the BeanInfo for this type has a BeanDescriptor which defined a "persistenceDelegate" property, this value is returned.
• In all other cases the default persistence delegate is returned. The default persistence delegate assumes the type is a JavaBean, implying that it has a default constructor and that its state may be characterized by the matching pairs of "setter" and "getter" methods returned by the Introspector. The default constructor is the constructor with the greatest number of parameters that has the {@link ConstructorProperties} annotation. If none of the constructors have the {@code ConstructorProperties} annotation, then the nullary constructor (constructor with no parameters) will be used. For example, in the following the nullary constructor for {@code Foo} will be used, while the two parameter constructor for {@code Bar} will be used. public class Foo { public Foo() { ... } public Foo(int x) { ... } } public class Bar { public Bar() { ... }

  Parameters:

  type - The type of the object.

  Returns:

  The persistence delegate for this type of object.

public Object remove(Object oldInstance)

public void setExceptionListener(ExceptionListener exceptionListener)

public void setPersistenceDelegate(Class type,
                                   PersistenceDelegate persistenceDelegate)

public void writeExpression(Expression oldExp)

protected void writeObject(Object o)

public void writeStatement(Statement oldStm)