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如何用powermock模拟fileinputstream?

  •  1
  • Sergio Rodríguez Calvo  · 技术社区  · 6 年前

    我正在尝试模拟fileinputstream,但是我无法让编译器使用模拟测试执行(总是得到filenotfoundexception)。

    我创建了一个使用fileinputstream的简单类:

    public class Class1 {
    
        public Class1() { }
    
        public boolean method1() {
            try {
                FileInputStream fileInputStream = new FileInputStream("file.txt");
            } catch (FileNotFoundException e) {
                e.printStackTrace();
                return false;
            }
            return true;
        }
    
    }
    

    我创建了一个简单的测试,如下所示:

    @RunWith(PowerMockRunner.class)
    @PrepareForTest(FileInputStream.class)
    public class Class1Test {
    
        @Test
        public void method1Test() throws Exception {
    
            Class1 class1 = new Class1();
    
            FileInputStream fileInputStreamMock = mock(FileInputStream.class);
    
            whenNew(FileInputStream.class).withAnyArguments().thenReturn(fileInputStreamMock);
    
            boolean expected = true;
            boolean actual = class1.method1();
    
            assertEquals(expected, actual);
    
        }
    
    }
    

    此处使用的依赖项有:

    <dependency>
            <groupId>org.powermock</groupId>
            <artifactId>powermock-module-junit4</artifactId>
            <version>1.7.4</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.powermock</groupId>
            <artifactId>powermock-api-mockito</artifactId>
            <version>1.7.4</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
    

    StackTrace如下:

    objc[30051]: Class JavaLaunchHelper is implemented in both /Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/bin/java (0x107c0a4c0) and /Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/libinstrument.dylib (0x107c8e4e0). One of the two will be used. Which one is undefined.
    java.io.FileNotFoundException: file.txt (No such file or directory)
        at java.io.FileInputStream.open0(Native Method)
        at java.io.FileInputStream.open(FileInputStream.java:195)
        at java.io.FileInputStream.<init>(FileInputStream.java:138)
        at java.io.FileInputStream.<init>(FileInputStream.java:93)
        at Class1.method1(Class1.java:10)
        at Class1Test.method1Test(Class1Test.java:31)
        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:497)
        at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:68)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:326)
        at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:89)
        at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:97)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:310)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:131)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.access$100(PowerMockJUnit47RunnerDelegateImpl.java:59)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner$TestExecutorStatement.evaluate(PowerMockJUnit47RunnerDelegateImpl.java:147)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.evaluateStatement(PowerMockJUnit47RunnerDelegateImpl.java:107)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:298)
        at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:87)
        at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:50)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:218)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:160)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:134)
        at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
        at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:136)
        at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:121)
        at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:57)
        at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
        at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
        at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
        at com.intellij.rt.execution.junit.IdeaTestRunner$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)
    
    java.lang.AssertionError: 
    Expected :true
    Actual   :false
     <Click to see difference>
    
    
        at org.junit.Assert.fail(Assert.java:88)
        at org.junit.Assert.failNotEquals(Assert.java:834)
        at org.junit.Assert.assertEquals(Assert.java:118)
        at org.junit.Assert.assertEquals(Assert.java:144)
        at Class1Test.method1Test(Class1Test.java:33)
        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:497)
        at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:68)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:326)
        at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:89)
        at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:97)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:310)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:131)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.access$100(PowerMockJUnit47RunnerDelegateImpl.java:59)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner$TestExecutorStatement.evaluate(PowerMockJUnit47RunnerDelegateImpl.java:147)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.evaluateStatement(PowerMockJUnit47RunnerDelegateImpl.java:107)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:298)
        at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:87)
        at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:50)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:218)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:160)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:134)
        at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
        at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
        at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:136)
        at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:121)
        at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:57)
        at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
        at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
        at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
        at com.intellij.rt.execution.junit.IdeaTestRunner$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)
    
    
    Process finished with exit code 255
    

    PowerMock能模仿这个对象吗?在网上阅读文档这应该很好…

    1 回复  |  直到 6 年前
        1
  •  4
  •   Jagrut Sharma    6 年前

    @PrepareForTest(Class1.class) @PrepareForTest(FileInputStream.class) Class1