org.axonframework.common.property
Class PropertyAccessStrategy

java.lang.Object
  org.axonframework.common.property.PropertyAccessStrategy

All Implemented Interfaces:

Comparable<PropertyAccessStrategy>

Direct Known Subclasses:

AbstractMethodPropertyAccessStrategy

public abstract class PropertyAccessStrategy
extends Object
implements Comparable<PropertyAccessStrategy>

Abstract Strategy that provides access to all PropertyAccessStrategy implementations.

Application developers may provide custom PropertyAccessStrategy implementations using the ServiceLoader mechanism. To do so, place a file called org.axonframework.common.property.PropertyAccessStrategy in the META-INF/services folder. In this file, place the fully qualified class names of all available implementations.

The factory implementations must be public, non-abstract, have a default public constructor and extend the PropertyAccessStrategy class.

Note that this class is not considered public API and may undergo incompatible changes between versions.

Since:

2.0

Author:

Maxim Fedorov, Allard Buijze

See Also:

ServiceLoader, ServiceLoader.load(Class)

Constructor Summary

PropertyAccessStrategy()

Method Summary

int	compareTo(PropertyAccessStrategy o)
protected abstract int	getPriority() The priority of this strategy.
static <T> Property<T>	getProperty(Class<T> targetClass, String propertyName) Iterates over all known PropertyAccessStrategy implementations to create a Property instance for the given parameters.
protected abstract <T> Property<T>	propertyFor(Class<T> targetClass, String property) Returns a Property instance for the given property, defined in given targetClass, or null if no such property is found on the class.
static void	register(PropertyAccessStrategy strategy) Registers a PropertyAccessStrategy implementation at runtime.
static void	unregister(PropertyAccessStrategy strategy) Removes all strategies registered using the register(PropertyAccessStrategy) method.

Methods inherited from class java.lang.Object

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

Constructor Detail

PropertyAccessStrategy

public PropertyAccessStrategy()

Method Detail

register

public static void register(PropertyAccessStrategy strategy)

Registers a PropertyAccessStrategy implementation at runtime. Annotated handlers that have already been inspected will not be able to use the newly added strategy.

Parameters:

strategy - implementation to register

unregister

public static void unregister(PropertyAccessStrategy strategy)

Removes all strategies registered using the register(PropertyAccessStrategy) method.

Parameters:

strategy - The strategy instance to unregister

getProperty

public static <T> Property<T> getProperty(Class<T> targetClass,
                                          String propertyName)

Iterates over all known PropertyAccessStrategy implementations to create a Property instance for the given parameters. Strategies are invoked in the order they are found on the classpath. The first to provide a suitable Property instance will be used.

Type Parameters:

T - Thy type defining the property

Parameters:

targetClass - class that contains property

propertyName - name of the property to create propertyReader for

Returns:

suitable Property, or null if none is found

compareTo

public final int compareTo(PropertyAccessStrategy o)

Specified by:

compareTo in interface Comparable<PropertyAccessStrategy>

getPriority

protected abstract int getPriority()

The priority of this strategy. In general, implementations that have a higher certainty to provide a good Property instance for any given property name should have a higher priority. When two instances have the same priority, their relative order is undefined.

The JavaBean Property strategy has a value of 0. To ensure evaluation before that strategy, use any value higher than that number, otherwise lower.

Returns:

a value reflecting relative priority, Integer.MAX_VALUE being evaluated first

propertyFor

protected abstract <T> Property<T> propertyFor(Class<T> targetClass,
                                               String property)

Returns a Property instance for the given property, defined in given targetClass, or null if no such property is found on the class.

Type Parameters:

T - The type of class on which to find the property

Parameters:

targetClass - The class on which to find the property

property - The name of the property to find

Returns:

the Property instance providing access to the property value, or null if property could not be found.