Module org.pojomatic

Package org.pojomatic

Class Pojomatic

java.lang.Object

org.pojomatic.Pojomatic

public class Pojomatic
extends Object

Static methods for implementing the Object.equals(Object), Object.hashCode() and Object.toString() methods on a annotated POJO. The actual work for a given class is done by a Pojomator created for that class. This class is careful to create only a single Pojomator per POJO class. The overhead for looking up the Pojomator by POJO class is light, so a typical use in a POJO class would be

@Override public int hashCode() {
return Pojomatic.hashCode(this);
}

@Override public boolean equals(Object other) {
return Pojomatic.equals(this, other);
}

@Override public String toString() {
return Pojomatic.toString(this);
}



Under the covers, these methods are referencing a Pojomator instance which is created lazily and cached on a per-class basis. The performance penalty for this is negligible, but if an interface is annotated for Pojomation, using the Pojomator directly is required, since the Pojomator for a class will only reference properties in the class and it's superclasses, but not any implemented interfaces. To do this, first define a static constant POJOMATOR in the interface:

import org.pojomatic.annotations.AutoProperty;
import org.pojomatic.Pojomator;
import org.pojomatic.Pojomatic;

@AutoProperty
public interface Interface {
static Pojomator<Interface> POJOMATOR = Pojomatic.pojomator(Interface.class);
...
}

and then delegate to POJOMATOR in the implementing classes:

public class Implementation implements Interface {
@Override public int hashCode() {
return POJOMATOR.doHashCode(this);
}

@Override public boolean equals(Object other) {
return POJOMATOR.doEquals(this, other);
}

@Override public String toString() {
return POJOMATOR.doToString(this);
}
...
}

See Also:

Pojomator

Method Summary

Modifier and Type	Method	Description
static boolean	areCompatibleForEquals(Class<?> classA, Class<?> classB)	Compute whether classA and classB are compatible for equality as specified by the documentation for Pojomator.isCompatibleForEquality(Class).
static <T,S extends T> Differences	diff(T pojo, S other)	Compute the differences between pojo and other among the properties examined by equals(Object, Object) for type T.
static <T> boolean	equals(T pojo, Object other)	Compute whether pojo and other are equal to each other in the sense of Object's equals method.
static <T> int	hashCode(T pojo)	Compute the hashCode for a POJO.
static <T> Pojomator<T>	pojomator(Class<T> pojoClass)	Get the Pojomator for pojoClass.
static <T> String	toString(T pojo)	Compute the toString representation for a POJO.

Methods inherited from class java.lang.Object

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

Method Detail

toString

public static <T> String toString(T pojo)
                           throws NoPojomaticPropertiesException

Compute the toString representation for a POJO.

Type Parameters:

T - the type of the POJO

Parameters:

pojo - the POJO - must not be null

Returns:

the toString representation of pojo.

Throws:

NoPojomaticPropertiesException - if pojo's class has no properties annotated for use with Pojomatic

See Also:

Pojomator.doToString(Object)

hashCode

public static <T> int hashCode(T pojo)
                        throws NoPojomaticPropertiesException

Compute the hashCode for a POJO.

Type Parameters:

T - the type of the POJO

Parameters:

pojo - the POJO - must not be null

Returns:

the hashCode for pojo.

Throws:

NoPojomaticPropertiesException - if pojo's class has no properties annotated for use with Pojomatic

See Also:

Pojomator.doHashCode(Object)

equals

public static <T> boolean equals(T pojo,
                                 Object other)
                          throws NoPojomaticPropertiesException

Compute whether pojo and other are equal to each other in the sense of Object's equals method.

Type Parameters:

T - the type of the POJO

Parameters:

pojo - the POJO - must not be null

other - the object to compare to for equality

Returns:

whether pojo and other are equal to each other in the sense of Object's equals method.

Throws:

NoPojomaticPropertiesException - if pojo's class has no properties annotated for use with Pojomatic

See Also:

Pojomator.doEquals(Object, Object)

areCompatibleForEquals

public static boolean areCompatibleForEquals(Class<?> classA,
                                             Class<?> classB)

Compute whether classA and classB are compatible for equality as specified by the documentation for Pojomator.isCompatibleForEquality(Class).

Parameters:

classA - the first class to check for compatibility for equality

classB - the second class to check for compatibility for equality

Returns:

true if the two classes are compatible for equality, or false otherwise.

diff

public static <T,S extends T> Differences diff(T pojo,
                                               S other)
                                        throws NullPointerException,
                                               NoPojomaticPropertiesException

Compute the differences between pojo and other among the properties examined by equals(Object, Object) for type T.

Type Parameters:

T - the static type of the first object to compare

S - the static type of the first object to compare

Parameters:

pojo - the instance to diff against

other - the instance to diff

Returns:

the list of differences (possibly empty) between instance and other among the properties examined by equals(Object, Object) for type T.

Throws:

NullPointerException - if pojo or other are null (this behavior may change in future releases).

NoPojomaticPropertiesException - if pojo's class has no properties annotated for use with Pojomatic, or if the types of pojo and other are not compatible for equality with each other (this behavior may change in future releases).

pojomator

public static <T> Pojomator<T> pojomator(Class<T> pojoClass)
                                  throws NoPojomaticPropertiesException

Get the Pojomator for pojoClass. While the same instance will be returned every time for a given value of pojoClass, highly performance-sensitive applications may want to cache the value returned in a static variable on the class in question. Note that a static Pojomator for a parent class will miss any additional properties when used on a child class.

Type Parameters:

T - the type represented by pojoClass

Parameters:

pojoClass - the class to create a Pojomator for.

Returns:

a Pojomator<T>

Throws:

NoPojomaticPropertiesException - if pojoClass has no properties annotated for use with Pojomatic