org.apache.jdo.impl.model.java

Class AbstractJavaType

java.lang.Object

org.apache.jdo.impl.model.java.AbstractJavaType

All Implemented Interfaces:

JavaType

Direct Known Subclasses:

BaseReflectionJavaType, ErrorType, NullType

public abstract class AbstractJavaType
extends java.lang.Object
implements JavaType

Abstract super class for JavaType implementations. It provides a default implementation for all methods except getName. The methods return the Java default value of the return type.

A non-abstract subclass must implement method getName() and needs to override any of the other methods where the default implementation is not appropriate.

Note, the class implements methods equals(Object obj), hashCode() and toString()using the name of a JavaType.

Since:

JDO 1.0.1

Author:

Michael Bouschen

Constructor Summary

Constructors

Constructor and Description
AbstractJavaType()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(java.lang.Object obj) Indicates whether some other object is "equal to" this one.
JavaType	getArrayComponentType() Returns the JavaType representing the component type of an array.
JavaField	getJavaField(java.lang.String name) Returns a JavaField instance that reflects the field with the specified name of the class or interface represented by this JavaType instance.
JDOClass	getJDOClass() Returns the JDOClass instance if this JavaType represents a persistence capable class.
int	getModifiers() Returns the Java language modifiers for the field represented by this JavaType, as an integer.
abstract java.lang.String	getName() Returns the name of the type.
JavaType	getSuperclass() Returns the JavaType representing the superclass of the entity represented by this JavaType.
int	hashCode() Returns a hash code value for the object.
boolean	isArray() Determines if this JavaType object represents an array type.
boolean	isCompatibleWith(JavaType javaType) Returns true if this JavaType is compatible with the specified JavaType.
boolean	isFloatingPoint() Returns true if this JavaType represents a floating point type.
boolean	isIntegral() Returns true if this JavaType represents an integral type.
boolean	isInterface() Determines if this JavaType object represents an interface type.
boolean	isJDOSupportedCollection() Returns true if this JavaType represents a JDO supported collection type.
boolean	isJDOSupportedMap() Returns true if this JavaType represents a JDO supported map type.
boolean	isOrderable() Returns true if this JavaType represents an orderable type as specified in JDO.
boolean	isPersistenceCapable() Returns true if this JavaType represents a persistence capable class.
boolean	isPrimitive() Returns true if this JavaType represents a primitive type.
boolean	isTrackable() Returns true if this JavaType represents a trackable Java class.
boolean	isValue() Returns true if this JavaType represents a type whose values may be treated as values rather than references during storing.
boolean	isWrapperClass() Returns true if this JavaType represents a Java wrapper class type.
java.lang.String	toString() Returns a string representation of the object.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

AbstractJavaType

public AbstractJavaType()

Method Detail

isPrimitive

public boolean isPrimitive()

Description copied from interface: JavaType

Returns true if this JavaType represents a primitive type.

There are eight primitive types: boolean, byte, short, int, long, char, float, double.

Specified by:

isPrimitive in interface JavaType

Returns:

true if this JavaType represents a primitive type; false otherwise.

isIntegral

public boolean isIntegral()

Description copied from interface: JavaType

Returns true if this JavaType represents an integral type.

There are five are integral types: byte, short, int, long, and char.

Specified by:

isIntegral in interface JavaType

Returns:

true if this JavaType represents an integral type; false otherwise.

isFloatingPoint

public boolean isFloatingPoint()

Description copied from interface: JavaType

Returns true if this JavaType represents a floating point type.

There are two are floating point types: float and double.

Specified by:

isFloatingPoint in interface JavaType

Returns:

true if this JavaType represents a floating point type; false otherwise.

isInterface

public boolean isInterface()

Description copied from interface: JavaType

Determines if this JavaType object represents an interface type.

Specified by:

isInterface in interface JavaType

Returns:

true if this object represents an interface type; false otherwise.

isArray

public boolean isArray()

Description copied from interface: JavaType

Determines if this JavaType object represents an array type.

Specified by:

isArray in interface JavaType

Returns:

true if this object represents an array type; false otherwise.

isWrapperClass

public boolean isWrapperClass()

Description copied from interface: JavaType

Returns true if this JavaType represents a Java wrapper class type.

There are eight Java wrapper class types: java.lang.Boolean, java.lang.Byte, java.lang.Short, java.lang.Integer, java.lang.Long, java.lang.Character, java.lang.Float, java.lang.Double.

Specified by:

isWrapperClass in interface JavaType

Returns:

true if this JavaType represents a Java wrapper class type; false otherwise.

isJDOSupportedCollection

public boolean isJDOSupportedCollection()

Description copied from interface: JavaType

Returns true if this JavaType represents a JDO supported collection type. The JDO specification allows the following collection interfaces and classes as types of persistent fields (see section 6.4.3 Persistent fields):

• java.util.Collection, java.util.Set, java.util.List
• java.util.HashSet, java.util.TreeSet
• java.util.ArrayList, java.util.LinkedList
• java.util.Vector, java.util.Stack

Specified by:

isJDOSupportedCollection in interface JavaType

Returns:

true if this JavaType represents a JDO supported collection; false otherwise.

isJDOSupportedMap

public boolean isJDOSupportedMap()

Description copied from interface: JavaType

Returns true if this JavaType represents a JDO supported map type. The JDO specification allows the following map interfaces and classes as types of persistent fields (see section 6.4.3 Persistent fields):

• java.util.Map
• java.util.HashMap, java.util.TreeMap
• java.util.Hashtable, java.util.Properties

Specified by:

isJDOSupportedMap in interface JavaType

Returns:

true if this JavaType represents a JDO supported map; false otherwise.

isTrackable

public boolean isTrackable()

Description copied from interface: JavaType

Returns true if this JavaType represents a trackable Java class. A JDO implementation may replace a persistent field of a trackable type with an assignment compatible instance of its own implementation of this type which notifies the owning FCO of any change of this field.

The following types are trackable types:

• JDO supported collection types
• JDO supported map types
• java.util.Date, java.sql.Date, java.sql.Time, java.sql.Timestamp
• java.util.BitSet

Specified by:

isTrackable in interface JavaType

Returns:

true if this JavaType represents a trackable Java class, false otherwise.

isValue

public boolean isValue()

Description copied from interface: JavaType

Returns true if this JavaType represents a type whose values may be treated as values rather than references during storing. A value type is either a primitive type or a type a JDO implementation may treat as SCO and the type is not one the following types: array, JDO supported collection and JDO supported map.

The following classes are value types:

• primitive types
• Java wrapper class types
• java.lang.Number, java.lang.String
• java.util.Locale
• java.math.BigDecimal, java.math.BigInteger
• java.util.Date, java.sql.Date, java.sql.Time, java.sql.Timestamp
• java.util.BitSet

Specified by:

isValue in interface JavaType

Returns:

true if this JavaType represents a value type; false otherwise.

isOrderable

public boolean isOrderable()

Description copied from interface: JavaType

Returns true if this JavaType represents an orderable type as specified in JDO.

The following types are orderable:

• primitive types except boolean
• Java wrapper class types except java.lang.Boolean
• java.lang.String
• java.math.BigDecimal, java.math.BigInteger
• java.util.Date, java.sql.Date, java.sql.Time, java.sql.Timestamp

Note, this method does not check whether this JavaType implements the Comparable interface.

Specified by:

isOrderable in interface JavaType

Returns:

true if this JavaType represents an orderable type; false otherwise.

isPersistenceCapable

public boolean isPersistenceCapable()

Description copied from interface: JavaType

Returns true if this JavaType represents a persistence capable class.

A ModelFatalException indicates a problem accessing the JDO meta data for this JavaType.

Specified by:

isPersistenceCapable in interface JavaType

Returns:

true if this JavaType represents a persistence capable class; false otherwise.

isCompatibleWith

public boolean isCompatibleWith(JavaType javaType)

Description copied from interface: JavaType

Returns true if this JavaType is compatible with the specified JavaType.

Specified by:

isCompatibleWith in interface JavaType

Parameters:

javaType - the type this JavaType is checked with.

Returns:

true if this is compatible with the specified type; false otherwise.

getName

public abstract java.lang.String getName()

Description copied from interface: JavaType

Returns the name of the type. If this type represents a class or interface, the name is fully qualified.

Specified by:

getName in interface JavaType

Returns:

type name

getModifiers

public int getModifiers()

Description copied from interface: JavaType

Returns the Java language modifiers for the field represented by this JavaType, as an integer. The java.lang.reflect.Modifier class should be used to decode the modifiers.

Specified by:

getModifiers in interface JavaType

Returns:

the Java language modifiers for this JavaType

getSuperclass

public JavaType getSuperclass()

Description copied from interface: JavaType

Returns the JavaType representing the superclass of the entity represented by this JavaType. If this JavaType represents either the Object class, an interface, a primitive type, or void, then null is returned. If this object represents an array class then the JavaType instance representing the Object class is returned.

Specified by:

getSuperclass in interface JavaType

Returns:

the superclass of the class represented by this JavaType.

getJDOClass

public JDOClass getJDOClass()

Description copied from interface: JavaType

Returns the JDOClass instance if this JavaType represents a persistence capable class. The method returns null, if this JavaType does not represent a persistence capable class.

A ModelFatalException indicates a problem accessing the JDO meta data for this JavaType.

Specified by:

getJDOClass in interface JavaType

Returns:

the JDOClass instance if this JavaType represents a persistence capable class; null otherwise.

getArrayComponentType

public JavaType getArrayComponentType()

Description copied from interface: JavaType

Returns the JavaType representing the component type of an array. If this JavaType does not represent an array type this method returns null.

Specified by:

getArrayComponentType in interface JavaType

Returns:

the JavaType representing the component type of this JavaType if this class is an array; null otherwise.

getJavaField

public JavaField getJavaField(java.lang.String name)

Description copied from interface: JavaType

Returns a JavaField instance that reflects the field with the specified name of the class or interface represented by this JavaType instance. The method returns null, if the class or interface (or one of its superclasses) does not have a field with that name.

Specified by:

getJavaField in interface JavaType

Parameters:

name - the name of the field

Returns:

the JavaField instance for the specified field in this class or null if there is no such field.

equals

public boolean equals(java.lang.Object obj)

Indicates whether some other object is "equal to" this one.

Overrides:

equals in class java.lang.Object

Parameters:

obj - the reference object with which to compare.

This implementation compares the name of the specified object to be equal to the name of this JavaType. this

Returns:

true if this object is the same as the obj argument; false otherwise.

hashCode

public int hashCode()

Returns a hash code value for the object.

This implementation returns the hashCode of the name of this JavaType.

Overrides:

hashCode in class java.lang.Object

Returns:

a hash code value for this object.

toString

public java.lang.String toString()

Returns a string representation of the object.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the object.