java Mockito when()需要一个参数,该参数必须是“模拟时的方法调用”错误
我正在为一个类编写单元测试,但遇到了一个错误
when() requires an argument which has to be a method call on a mock
即使我正在使用模拟对象调用when()
。这是代码
package assign.resources;
import static org.junit.Assert.*;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
import javax.ws.rs.core.StreamingOutput;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import assign.domain.*;
import assign.services.*;
public class TestTrafficCameraReportsResource {
@Mock
TrafficCameraReportsService mockService = null;
TrafficCameraReportsResource reportsResource = new TrafficCameraReportsResource();
@Before
public void setUp() {
mockService = mock(TrafficCameraReportsService.class);
reportsResource.setReportService(mockService);
}
@Test
public void unitTest1() throws Exception {
when(mockService.getReportsList()).thenReturn(null); //this is the line causing the error
StreamingOutput allReports = reportsResource.getTrafficCameraReports();
assertEquals(null, allReports);
}
当我在网上查找这个错误时,人们得到它是因为他们没有使用模拟对象,而我使用的是模拟对象mockService
。你知道为什么会这样吗
错误:
TestTrafficCameraReportsResource
assign.resources.TestTrafficCameraReportsResource
unitTest1(assign.resources.TestTrafficCameraReportsResource)
org.mockito.exceptions.misusing.MissingMethodInvocationException:
when() requires an argument which has to be 'a method call on a mock'.
For example:
when(mock.getArticles()).thenReturn(articles);
Also, this error might show up because:
1. you stub either of: final/private/equals()/hashCode() methods.
Those methods *cannot* be stubbed/verified.
2. inside when() you don't call method on mock but on some other object.
3. the parent of the mocked class is not public.
It is a limitation of the mock engine.
at assign.resources.TestTrafficCameraReportsResource.unitTest1(TestTrafficCameraReportsResource.java:29)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
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.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
# 1 楼答案
弄明白了,getReportsList是静态的,所以它没有意识到它是从mockService调用的。清除静电起作用了
# 2 楼答案
您需要使用
@RunWith(MockitoJUnitRunner.class)
(或者任何其他运行程序,如果您使用的是spring或其他框架),来注释您的类此外,您的字段上有一个
@Mock
注释,并使用mock()
方法对其进行赋值。不需要同时使用这两个选项,您只能留下一个(如果是注释,请删除= null;
)