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Mock objects library for java

There is a newer version: 2.0.2-beta

/*
 * Copyright (c) 2007 Mockito contributors
 * This program is made available under the terms of the MIT License.
 */
package org.mockito;

import java.lang.annotation.*;

/**
 * Allows shorthand wrapping of field instances in an spy object.
 * 
 * 
 * Example:
 * 
 * 

 * public class Test{
 *    //Instance for spying is created by calling constructor explicitly:
 *    @Spy Foo spyOnFoo = new Foo("argument");
 *    //Instance for spying is created by mockito via reflection (only default constructors supported): 
 *    @Spy Bar spyOnBar;
 *    @Before
 *    public void init(){
 *       MockitoAnnotations.initMocks(this);
 *    }
 *    ...
 * }
 * 
 * 
 * Same as doing:
 * 
 * 

 * Foo spyOnFoo = Mockito.spy(new Foo("argument"));
 * Bar spyOnFoo = Mockito.spy(new Bar());
 * 
 *
 * The field annotated with @Spy can be initialized by Mockito if a zero argument constructor
 * can be found in the type (even private). But Mockito cannot instantiate inner classes, local classes,
 * abstract classes and interfaces.
 *
 * The field annotated with @Spy can be initiatialized explicitly at declaration point.
 * Alternatively, if you don't provide the instance Mockito will try to find zero argument constructor (even private) and create an instance for you.
 * But Mockito cannot instantiate inner classes, local classes, abstract classes and interfaces.
 *
 * For example this class can be instantiated by Mockito :
 * public class Bar {
 *    private Bar() {}
 *    public Bar(String publicConstructorWithOneArg) {}
 * }
 * 
 * 
 * 
 * Warning if you call MockitoAnnotations.initMocks(this) in a
 * super class constructor then this will not work. It is because fields
 * in subclass are only instantiated after super class constructor has returned.
 * It's better to use @Before.
 * 
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
@Documented
public @interface Spy {
}