blocks|key|121972|text|如果你想存根出实例返回的内容，你可以这样做，但这有点麻烦(使用反射和字节码操作)。我使用PowerMock+1.4.12+/+Mockito+1.9.0创建并测试了一个包含三个类的简单项目。所有的类都在同一个包中。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|121973|SingletonObject.java|121974|public+enum+SingletonObject+{
++++INSTANCE;
++++private+int+num;

++++protected+void+setNum(int+num)+{
++++++++this.num+=+num;
++++}

++++public+int+getNum()+{
++++++++return+num;
++++}
}|code-block|syntax|javascript|121975|SingletonConsumer.java|121976|public+class+SingletonConsumer+{
++++public+String+consumeSingletonObject()+{
++++++++return+String.valueOf(SingletonObject.INSTANCE.getNum());
++++}
}|121977|SingletonConsumerTest.java|121978|import+static+org.junit.Assert.*;
import+static+org.powermock.api.mockito.PowerMockito.*;

import+org.junit.Test;
import+org.junit.runner.RunWith;
import+org.powermock.core.classloader.annotations.PrepareForTest;
import+org.powermock.modules.junit4.PowerMockRunner;
import+org.powermock.reflect.Whitebox;

@RunWith(PowerMockRunner.class)
@PrepareForTest({SingletonObject.class})
public+class+SingletonConsumerTest+{
++++@Test
++++public+void+testConsumeSingletonObject()+throws+Exception+{
++++++++SingletonObject+mockInstance+=+mock(SingletonObject.class);
++++++++Whitebox.setInternalState(SingletonObject.class,+"INSTANCE",+mockInstance);

++++++++when(mockInstance.getNum()).thenReturn(42);

++++++++assertEquals("42",+new+SingletonConsumer().consumeSingletonObject());
++++}
}|121979|对Whitebox.setInternalState的调用将INSTANCE替换为您可以在测试中操作的模拟对象。|offset|length|style|CODE|121980|entityMap^0|0|0|0|0|0|0|0|1|P|U|8|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Z|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|11|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|12|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|14|8|@]|9|@]|A|$G|H]]|$1|Q|3|R|5|6|7|15|8|@$S|16|T|17|U|V]|$S|18|T|19|U|V]]|9|@]|A|$]]|$1|W|3|-4|5|6|7|1A|8|@]|9|@]|A|$]]]|X|$]]

<p>If you want to stub out what INSTANCE returns, you can do it but it's kind of nasty (using reflection &amp; bytecode manipulation). I created &amp; tested a simple project with three classes using the PowerMock 1.4.12 / Mockito 1.9.0. All classes were in the same package.</p>

<h1>SingletonObject.java</h1>

<pre><code>public enum SingletonObject {
    INSTANCE;
    private int num;

    protected void setNum(int num) {
        this.num = num;
    }

    public int getNum() {
        return num;
    }
}
</code></pre>

<h1>SingletonConsumer.java</h1>

<pre><code>public class SingletonConsumer {
    public String consumeSingletonObject() {
        return String.valueOf(SingletonObject.INSTANCE.getNum());
    }
}
</code></pre>

<h1>SingletonConsumerTest.java</h1>

<pre><code>import static org.junit.Assert.*;
import static org.powermock.api.mockito.PowerMockito.*;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import org.powermock.reflect.Whitebox;

@RunWith(PowerMockRunner.class)
@PrepareForTest({SingletonObject.class})
public class SingletonConsumerTest {
    @Test
    public void testConsumeSingletonObject() throws Exception {
        SingletonObject mockInstance = mock(SingletonObject.class);
        Whitebox.setInternalState(SingletonObject.class, "INSTANCE", mockInstance);

        when(mockInstance.getNum()).thenReturn(42);

        assertEquals("42", new SingletonConsumer().consumeSingletonObject());
    }
}
</code></pre>

<p>The call to the <code>Whitebox.setInternalState</code> replaces <code>INSTANCE</code> with a mock object that you can manipulate within your test.</p>


blocks|key|121990|text|具有与您打算模拟的方法的接口|type|unstyled|depth|inlineStyleRanges|entityRanges|data|121991|public+interface+SingletonInterface+{
++int+getNum();
}|code-block|syntax|javascript|121992|让枚举实现接口|121993|public+enum+SingletonObject+implements+SingletonInterface+{
++++INSTANCE;
++++private+int+num;

++++protected+void+setNum(int+num)+{
++++++++this.num+=+num;
++++}

++++@Override
++++public+int+getNum()+{
++++++++return+num;
++++}
}|121994|模拟接口|121995|@Test
public+void+test()+{
++SingletonInterface+singleton+=+Mockito.mock(SingletonInterface.class);
++when(singleton.getNum()).thenReturn(1);+//does+work
}|121996|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

<p>Have an interface with the methods you intend to mock</p>

<pre><code>public interface SingletonInterface {
  int getNum();
}
</code></pre>

<p>Let the enum implement the interface</p>

<pre><code>public enum SingletonObject implements SingletonInterface {
    INSTANCE;
    private int num;

    protected void setNum(int num) {
        this.num = num;
    }

    @Override
    public int getNum() {
        return num;
    }
}
</code></pre>

<p>Mock the interface</p>

<pre><code>@Test
public void test() {
  SingletonInterface singleton = Mockito.mock(SingletonInterface.class);
  when(singleton.getNum()).thenReturn(1); //does work
}
</code></pre>


blocks|key|122017|text|除了上面Matt+Lachman回答之外，在SingleTonConsumerTest.class中为power模拟创建一个对象工厂|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|122018|@ObjectFactory
public+IObjectFactory+getObjectFactory()+{
++++return+new+org.powermock.modules.testng.PowerMockObjectFactory();
}|code-block|syntax|javascript|122019|这将删除Mockito+cannot+mock/spy+following:+-+final+classes+-+anonymous+classes+-+primitive+types错误。|122020|entityMap^0|M|R|0|0|4|2G|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

<p>In addition to above Matt Lachman answer, create a object factory for power mock in <code>SingleTonConsumerTest.class</code> </p>

<pre><code>@ObjectFactory
public IObjectFactory getObjectFactory() {
    return new org.powermock.modules.testng.PowerMockObjectFactory();
}
</code></pre>

<p>This will remove <code>Mockito cannot mock/spy following: - final classes - anonymous classes - primitive types</code> error.</p>


blocks|key|122033|text|我不确定这是否是最好的方法，但在我的例子中，到目前为止，它工作得很顺利。我使用mockito-core和mockito-inline+(3.11.0)，我在spy的帮助下模拟我的单例。以您的类为例：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|122034|SingletonObject+so+=+SingletonObject.INSTANCE;
private+SingletonObject+spySo+=+Mockito.spy(so);

@Before
public+void+setUp()+{
++++Mockito.doReturn(10).when(spySo).getNum();
}

@Test
public+void+simpleTest()+{
++++assertThat(spySo.getNum(),+is(10));
}|code-block|syntax|javascript|122035|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>I am not sure if this is best approach, but in my case it's working without troubles so far. I am using mockito-core and mockito-inline (3.11.0) and I am mocking my singleton with help of spy. Example with your class:</p>
<pre><code>SingletonObject so = SingletonObject.INSTANCE;
private SingletonObject spySo = Mockito.spy(so);

@Before
public void setUp() {
    Mockito.doReturn(10).when(spySo).getNum();
}

@Test
public void simpleTest() {
    assertThat(spySo.getNum(), is(10));
}
</code></pre>


<p>I am unsure on how to mock an enum singleton class.</p>

<pre><code>public enum SingletonObject{
  INSTANCE;
  private int num;

  protected setNum(int num) {
    this.num = num;
  }

  public int getNum() {
    return num;
  }
</code></pre>

<p>I'd like to stub getNum() in the above example, but I can't figure out how to mock the actual SingletonObject class.  I thought using Powermock to prepare the test would help since enums are inherently final.</p>

<pre><code>//... rest of test code
@Test
public void test() {
  PowerMockito.mock(SingletonObject.class);
  when(SingletonObject.INSTANCE.getNum()).thenReturn(1); //does not work
}
</code></pre>

<p>This is using PowerMockMockito 1.4.10 and Mockito 1.8.5.</p>


How to mock an enum singleton class using Mockito/Powermock?

我不确定如何模拟枚举单例类。public enum SingletonObject{  INSTANCE;  private int num;  protected setNum(int num) {    this.num = num;  }  public int getNum() {    return num;...

问如何使用Mockito/Powermock模拟枚举单例类？
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