com.googlecode.objectify.impl.translate

Class ValueTranslator<P,D>

java.lang.Object

com.googlecode.objectify.impl.translate.NullSafeTranslator<P,D>

com.googlecode.objectify.impl.translate.ProjectionSafeTranslator<P,D>

com.googlecode.objectify.impl.translate.ValueTranslator<P,D>

All Implemented Interfaces:

Translator<P,D>

public abstract class ValueTranslator<P,D>
extends ProjectionSafeTranslator<P,D>

A bit of code that does the required type checking and casting so that we have nice typed methods. Also handles the RawValue case of projection queries. Note that null checking has already been done.

Author:

Jeff Schnitzer

Constructor Summary

Constructors

Constructor and Description
ValueTranslator(Class<D> datastoreClass)
ValueTranslator(Class<D> datastoreClass, Class<? extends D> projectionClass) Sometimes the projection class is more specific than the datastore class

Method Summary

Modifier and Type	Method and Description
protected P	loadSafe2(D value, LoadContext ctx, Path path) Decode from a property value as stored in the datastore to a type that will be stored in a pojo.
protected abstract P	loadValue(D value, LoadContext ctx, Path path) Decode from a property value as stored in the datastore to a type that will be stored in a pojo.
protected D	saveSafe(P pojo, boolean index, SaveContext ctx, Path path) Implement this, returning a proper translated value
protected abstract D	saveValue(P value, boolean index, SaveContext ctx, Path path) Encode from a normal pojo value to a format that the datastore understands.

Methods inherited from class com.googlecode.objectify.impl.translate.ProjectionSafeTranslator

loadSafe

Methods inherited from class com.googlecode.objectify.impl.translate.NullSafeTranslator

load, save

Methods inherited from class java.lang.Object

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

Constructor Detail

ValueTranslator

public ValueTranslator(Class<D> datastoreClass)

ValueTranslator

public ValueTranslator(Class<D> datastoreClass,
                       Class<? extends D> projectionClass)

Sometimes the projection class is more specific than the datastore class

Method Detail

loadSafe2

protected final P loadSafe2(D value,
                            LoadContext ctx,
                            Path path)
                     throws SkipException

Description copied from class: ProjectionSafeTranslator

Decode from a property value as stored in the datastore to a type that will be stored in a pojo.

Specified by:

loadSafe2 in class ProjectionSafeTranslator<P,D>

Parameters:

value - will not be null and will not be RawValue

Returns:

the format which should be stored in the pojo; a null means store a literal null!

Throws:

SkipException - if this field subtree should be skipped

saveSafe

protected final D saveSafe(P pojo,
                           boolean index,
                           SaveContext ctx,
                           Path path)
                    throws SkipException

Description copied from class: NullSafeTranslator

Implement this, returning a proper translated value

Specified by:

saveSafe in class NullSafeTranslator<P,D>

Parameters:

pojo - will never be null

Throws:

SkipException

loadValue

protected abstract P loadValue(D value,
                               LoadContext ctx,
                               Path path)
                        throws SkipException

Decode from a property value as stored in the datastore to a type that will be stored in a pojo.

Parameters:

value - will not be null and will actually be the correct type

Returns:

the format which should be stored in the pojo; a null means store a literal null!

Throws:

SkipException - if this field subtree should be skipped

saveValue

protected abstract D saveValue(P value,
                               boolean index,
                               SaveContext ctx,
                               Path path)
                        throws SkipException

Encode from a normal pojo value to a format that the datastore understands. Note that a null return value is a literal instruction to store a null.

Parameters:

value - will not be null

Returns:

the format which should be stored in the datastore; null means actually store a null!

Throws:

SkipException - if this subtree should be skipped