如何使用mockito模拟泛型方法？

Question

我正试图模拟一个泛型方法，但无论我做什么尝试，都会得到类转换异常。正在测试的类是

public class TClass {
    private byte[] data;
    public <T extends SInterface> T asObject(T item){
        item.SMethod(this.getData());
        return item;
    }

    private byte[] getData() {
        return data;
    }
}

而测试类是

@RunWith(MockitoJUnitRunner.class)
public class TClassTest {
    @Mock
    SSInterface sClass;
    @Mock
    SObject sObject;

    TClass tClass = new TClass();


    @org.junit.Before
    public void setUp() throws Exception {
    }

    @org.junit.Test
    public void asObject() {
        Mockito.when(tClass.asObject(new SSClass())).thenReturn(sClass);
    }
}

其他帮助器类和接口有：

 public interface SInterface {
    public void SMethod(byte[] in);
}



public interface SSInterface extends SInterface {
}


public class SSClass implements SSInterface {
    @Override
    public void SMethod(byte[] in) {
    }
}

public class SObject {
}

此外，出现此错误的原因可能是：1。您使用final/private/equals()/hashCode（）方法中的任一个作为存根。这些方法不能被截取/验证。不支持在非公共父类上声明的模拟方法。2.内部when（）不是对mock而是对其他对象调用method。

at generic.TClassTest.asObject(TClassTest.java:26)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:78)
at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:84)
at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:161)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Answer 1

您有不兼容的类型，这与mockito无关。asObject()返回与接收到的类型相同的类型，并且必须是sInterface类型。

根据您尝试实现的目标，ou可以返回ssclasss的实例：

Mockito.when(tClass.asObject(new SSClass())).thenReturn( new SSClass());

或者您可以使tclass扩展sinterface，然后：