com.persistit.encoding

Class SerialValueCoder

java.lang.Object

com.persistit.encoding.SerialValueCoder

All Implemented Interfaces:

ValueCoder

public final class SerialValueCoder
extends Object
implements ValueCoder

A ValueCoder that uses standard Java serialization to store and retrieve object values. This class is related to DefaultValueCoder. When Persistit serializes or deserializes an object for which there is no registered ValueCoder, it implicitly constructs either a DefaultValueCoder or a SerialValueCoder, depending on the value of the serialOverride property. See Persistit Object Serialization for details.

This class creates a new java.io.ObjectInputStream each time it is called upon to deserialize an instance of its client class, or a java.io.ObjectOutputStream to serialize an instance. The format of the stored data is specified by the Java Object Serialization Specification with one exception: the class descriptor is replaced by a handle; an association between handles and class descriptors is maintained in a separate metadata tree. This avoids redundantly storing class descriptors for multiple instance of the same class.

Since:

1.1

Version:

1.1

Constructor Summary

Constructors

Constructor and Description
SerialValueCoder(Class<?> clazz)

Method Summary

Modifier and Type	Method and Description
Object	get(Value value, Class<?> clazz, CoderContext context) Creates an instance of the supplied class, populates its state by decoding the supplied Value using standard Java serialization, and returns it.
void	put(Value value, Object object, CoderContext context) Encodes the supplied Object into the supplied Value using standard Java serialization.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SerialValueCoder

public SerialValueCoder(Class<?> clazz)

Method Detail

get

public Object get(Value value,
                  Class<?> clazz,
                  CoderContext context)

Creates an instance of the supplied class, populates its state by decoding the supplied Value using standard Java serialization, and returns it. This method will be called only if this ValueCoder has been registered with the current CoderManager to encode objects having supplied Class value. Persistit will never call this method to decode a value that was null when written because null values are handled by built-in encoding logic.

Specified by:

get in interface ValueCoder

Parameters:

value - The Value from which interior fields of the object are to be retrieved

clazz - The class of the object to be returned.

context - An arbitrary object that can optionally be supplied by the application to convey an application-specific context for the operation. (See CoderContext.) The default value is null. For SerialValueCoder this parameter is always ignored.

Returns:

An Object having the same class as the suppled clazz parameter.

Throws:

ConversionException

put

public void put(Value value,
                Object object,
                CoderContext context)

Encodes the supplied Object into the supplied Value using standard Java serialization. This method will be called only if this ValueCoder has been registered with the current CoderManager to encode objects having the class of the supplied object.

Upon completion of this method, the backing byte array of the Value and its size should be updated to reflect the appended key segment. Use the methods Value.getEncodedBytes(), Value.getEncodedSize() and Value.setEncodedSize(int) to manipulate the byte array directly. More commonly, the implementation of this method will simply call the appropriate put methods to write the interior field values into the Value object.

Specified by:

put in interface ValueCoder

Parameters:

value - The Value to which the interior data of the supplied Object should be encoded

object - The object value to encode. This parameter will never be null because Persistit encodes nulls with a built-in encoding.

context - An arbitrary object that can optionally be supplied by the application to convey an application-specific context for the operation. (See CoderContext.) The default value is null. For SerialValueCoder this parameter is always ignored.