Mockito
@Mock(answer = Answers.RETURNS_DEEP_STUBS)
package com.test.junitTest; import static org.junit.Assert.assertEquals; import static org.mockito.Mockito.doThrow; import static org.mockito.Mockito.mock; import static org.mockito.Mockito.verify; import static org.mockito.Mockito.when; import java.io.IOException; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.util.Arrays; import java.util.Comparator; import java.util.Iterator; import java.util.List; import org.junit.Test; import org.mockito.ArgumentMatcher; import org.mockito.invocation.InvocationOnMock; import org.mockito.stubbing.Answer; import static org.mockito.Mockito.*; import static org.junit.Assert.*; public class MockitoTest { @Test public void verify_behaviour() { // 模拟创建一个List对象 List mock = mock(List.class); // 使用mock的对象 mock.add(1); mock.clear(); // 验证add(1)和clear()行为是否发生 verify(mock).add(1); verify(mock).clear(); } @Test public void when_thenReturn() { // mock一个Iterator类 Iterator iterator = mock(Iterator.class); // 预设当iterator调用next()时第一次返回hello,第n次都返回world when(iterator.next()).thenReturn("hello").thenReturn("world"); // 使用mock的对象 String result = iterator.next() + " " + iterator.next() + " " + iterator.next(); // 验证结果 assertEquals("hello world world", result); } @Test(expected = IOException.class) public void when_thenThrow() throws IOException { OutputStream outputStream = mock(OutputStream.class); OutputStreamWriter writer = new OutputStreamWriter(outputStream); // 预设当流关闭时抛出异常 doThrow(new IOException()).when(outputStream).close(); outputStream.close(); } @Test public void returnsSmartNullsTest() { List mock = mock(List.class, RETURNS_SMART_NULLS); // List mock = mock(List.class); // 使用RETURNS_SMART_NULLS参数创建的mock对象,不会抛出NullPointerException异常。另外控制台窗口会提示信息“SmartNull returned // by unstubbed get() method on mock” // System.out.println(mock.toArray().length); } @Test public void with_arguments() { Comparable comparable = mock(Comparable.class); // 预设根据不同的参数返回不同的结果 when(comparable.compareTo("Test")).thenReturn(1); when(comparable.compareTo("Omg")).thenReturn(2); assertEquals(1, comparable.compareTo("Test")); assertEquals(2, comparable.compareTo("Omg")); // 对于没有预设的情况会返回默认值 assertEquals(0, comparable.compareTo("Not stub")); } @Test public void with_unspecified_arguments() { List list = mock(List.class); // 匹配任意参数 when(list.get(anyInt())).thenReturn(1); when(list.contains(argThat(new IsValid()))).thenReturn(true); assertEquals(1, list.get(1)); assertEquals(1, list.get(999)); assertTrue(list.contains(1)); assertTrue(!list.contains(3)); } private class IsValid extends ArgumentMatcher<List> { @Override public boolean matches(Object o) { return o.equals(1) || o.equals(2); } } @Test public void all_arguments_provided_by_matchers() { Comparator comparator = mock(Comparator.class); comparator.compare("nihao", "hello"); // 如果你使用了参数匹配,那么所有的参数都必须通过matchers来匹配 verify(comparator).compare(anyString(), eq("hello")); // 下面的为无效的参数匹配使用 // verify(comparator).compare(anyString(), "hello"); } @Test public void argumentMatchersTest() { // 创建mock对象 List<String> mock = mock(List.class); // argThat(Matches<T> matcher)方法用来应用自定义的规则,可以传入任何实现Matcher接口的实现类。 when(mock.addAll(argThat(new IsListofTwoElements()))).thenReturn(true); mock.addAll(Arrays.asList("one", "two", "three")); // IsListofTwoElements用来匹配size为2的List,因为例子传入List为三个元素,所以此时将失败。 verify(mock).addAll(argThat(new IsListofTwoElements())); } class IsListofTwoElements extends ArgumentMatcher<List> { public boolean matches(Object list) { return ((List) list).size() == 3; } } @Test public void unstubbed_invocations() { // mock对象使用Answer来对未预设的调用返回默认期望值 List mock = mock(List.class, new Answer() { @Override public Object answer(InvocationOnMock invocation) throws Throwable { return 999; } }); // 下面的get(1)没有预设,通常情况下会返回NULL,但是使用了Answer改变了默认期望值 assertEquals(999, mock.get(1)); // 下面的size()没有预设,通常情况下会返回0,但是使用了Answer改变了默认期望值 assertEquals(999, mock.size()); } @Test public void answer_with_callback() { List mockList = mock(List.class); // 使用Answer来生成我们我们期望的返回 when(mockList.get(anyInt())).thenAnswer(new Answer<Object>() { @Override public Object answer(InvocationOnMock invocation) throws Throwable { Object[] args = invocation.getArguments(); return "hello world:" + args[0]; } }); assertEquals("hello world:0", mockList.get(0)); assertEquals("hello world:999", mockList.get(999)); } @Test(expected = RuntimeException.class) public void consecutive_calls() { List mockList = mock(List.class); // 模拟连续调用返回期望值,如果分开,则只有最后一个有效 when(mockList.get(0)).thenReturn(0); when(mockList.get(0)).thenReturn(1); when(mockList.get(0)).thenReturn(2); when(mockList.get(1)).thenReturn(0).thenReturn(1).thenThrow(new RuntimeException()); assertEquals(2, mockList.get(0)); assertEquals(2, mockList.get(0)); assertEquals(0, mockList.get(1)); assertEquals(1, mockList.get(1)); // 第三次或更多调用都会抛出异常 mockList.get(1); } }
@RunWith(MockitoJUnitRunner.class)
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.test</groupId> <artifactId>junitTest</artifactId> <version>0.0.1-SNAPSHOT</version> <name>junitTest</name> <dependencies> <!-- junit --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>org.mockito</groupId> <artifactId>mockito-all</artifactId> <version>1.9.5</version> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.8</source> <target>1.8</target> </configuration> </plugin> </plugins> </build> </project>
ReflectionTestUtils.setField