java.io
Class ObjectStreamField

java.lang.Object
  java.io.ObjectStreamField

All Implemented Interfaces:

Comparable

public class ObjectStreamField

extends Object

implements Comparable

A description of a Serializable field from a Serializable class. An array of ObjectStreamFields is used to declare the Serializable fields of a class.

Since:

1.2

Author:

Mike Warres, Roger Riggs

See Also:

ObjectStreamClass

Field Summary

private Field	field corresponding reflective field object, if any
private String	name field name
private int	offset offset of field value in enclosing field group
private String	signature canonical JVM signature of field type
private Class	type field type (Object.class if unknown non-primitive type)
private boolean	unshared whether or not to (de)serialize field values as unshared

Constructor Summary

(package private)	ObjectStreamField(Field field, boolean unshared, boolean showType) Creates an ObjectStreamField representing the given field with the specified unshared setting.
	ObjectStreamField(String name, Class type) Create a Serializable field with the specified type.
	ObjectStreamField(String name, Class type, boolean unshared) Creates an ObjectStreamField representing a serializable field with the given name and type.
(package private)	ObjectStreamField(String name, String signature, boolean unshared) Creates an ObjectStreamField representing a field with the given name, signature and unshared setting.

Method Summary

int	compareTo(Object obj) Compare this field with another ObjectStreamField.
(package private) Field	getField() Returns field represented by this ObjectStreamField, or null if ObjectStreamField is not associated with an actual field.
String	getName() Get the name of this field.
int	getOffset() Offset of field within instance data.
(package private) String	getSignature() Returns JVM type signature of field (similar to getTypeString, except that signature strings are returned for primitive fields as well).
Class	getType() Get the type of the field.
char	getTypeCode() Returns character encoding of field type.
String	getTypeString() Return the JVM type signature.
boolean	isPrimitive() Return true if this field has a primitive type.
boolean	isUnshared() Returns boolean value indicating whether or not the serializable field represented by this ObjectStreamField instance is unshared.
protected void	setOffset(int offset) Offset within instance data.
String	toString() Return a string that describes this field.

Methods inherited from class java.lang.Object

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

Field Detail

name

private final String name

field name

signature

private final String signature

canonical JVM signature of field type

type

private final Class type

field type (Object.class if unknown non-primitive type)

unshared

private final boolean unshared

whether or not to (de)serialize field values as unshared

field

private final Field field

corresponding reflective field object, if any

offset

private int offset

offset of field value in enclosing field group

Constructor Detail

ObjectStreamField

public ObjectStreamField(String name,
                         Class type)

Create a Serializable field with the specified type. This field should be documented with a serialField tag.

Parameters:

name - the name of the serializable field

type - the Class object of the serializable field

ObjectStreamField

public ObjectStreamField(String name,
                         Class type,
                         boolean unshared)

Creates an ObjectStreamField representing a serializable field with the given name and type. If unshared is false, values of the represented field are serialized and deserialized in the default manner--if the field is non-primitive, object values are serialized and deserialized as if they had been written and read by calls to writeObject and readObject. If unshared is true, values of the represented field are serialized and deserialized as if they had been written and read by calls to writeUnshared and readUnshared.

Parameters:

name - field name

type - field type

unshared - if false, write/read field values in the same manner as writeObject/readObject; if true, write/read in the same manner as writeUnshared/readUnshared

ObjectStreamField

ObjectStreamField(String name,
                  String signature,
                  boolean unshared)

Creates an ObjectStreamField representing a field with the given name, signature and unshared setting.

ObjectStreamField

ObjectStreamField(Field field,
                  boolean unshared,
                  boolean showType)

Creates an ObjectStreamField representing the given field with the specified unshared setting. For compatibility with the behavior of earlier serialization implementations, a "showType" parameter is necessary to govern whether or not a getType() call on this ObjectStreamField (if non-primitive) will return Object.class (as opposed to a more specific reference type).

Method Detail

getName

public String getName()

Get the name of this field.

Returns:

a String representing the name of the serializable field

getType

public Class getType()

Get the type of the field.

Returns:

the Class object of the serializable field

getTypeCode

public char getTypeCode()

Returns character encoding of field type. The encoding is as follows:

 B            byte
 C            char
 D            double
 F            float
 I            int
 J            long
 L            class or interface
 S            short
 Z            boolean
 [            array
 

Returns:

the typecode of the serializable field

getTypeString

public String getTypeString()

Return the JVM type signature.

Returns:

null if this field has a primitive type.

getOffset

public int getOffset()

Offset of field within instance data.

Returns:

the offset of this field

See Also:

setOffset(int)

setOffset

protected void setOffset(int offset)

Offset within instance data.

Parameters:

offset - the offset of the field

See Also:

getOffset()

isPrimitive

public boolean isPrimitive()

Return true if this field has a primitive type.

Returns:

true if and only if this field corresponds to a primitive type

isUnshared

public boolean isUnshared()

Returns boolean value indicating whether or not the serializable field represented by this ObjectStreamField instance is unshared.

compareTo

public int compareTo(Object obj)

Compare this field with another ObjectStreamField. Return -1 if this is smaller, 0 if equal, 1 if greater. Types that are primitives are "smaller" than object types. If equal, the field names are compared.

Specified by:

compareTo in interface Comparable

Parameters:

obj - the Object to be compared.

Returns:

a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

toString

public String toString()

Return a string that describes this field.

Overrides:

toString in class Object

Returns:

a string representation of the object.

getField

Field getField()

Returns field represented by this ObjectStreamField, or null if ObjectStreamField is not associated with an actual field.

getSignature

String getSignature()

Returns JVM type signature of field (similar to getTypeString, except that signature strings are returned for primitive fields as well).