Mockito常用方法及示例

Mockito常⽤⽅法及⽰例
要使⽤Mockit，⾸先需要在我们⼯程中引⼊对应的jar包，对于maven⼯程⽽⾔，需要添加如下依赖项即可：<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-core</artifactId>
<version>2.0.5-beta</version>
</dependency>
⽽在我们实际使⽤时，为了组织测试case的需要，我们可能还需要testng：
<dependency>
<groupId>org.testng</groupId>
<artifactId>testng</artifactId>
<version>6.8.8</version>
<scope>test</scope>
</dependency>
在进⾏下⾯的mock test⽰例之前，我们先建两个简单的被测类Demo、ParameterClass。

Demo.java:
package com.anlegor.test;
public class Demo {
private String name ="laowang";
private int age;
public Demo(String name, int age) {
= name;
this.age = age;
}
public String speak(String str) {
return str;
}
public String talk(String str)
{
return str;
}
public String methodNoParameters()
{
return name;
}
public String methodCustomParameters(ParameterClass parameter,String str)
{
return str;
}
public String methodHaveChildObj(ParameterClass parameter,String str)
{
parameter.childTalk(str);
return str;
}
}
ParameterClass.java
package com.anlegor.test;
public class ParameterClass {
public ParameterClass() {
}
public String childTalk(String str)
{
return str;
}
}
我们在进⾏mock的时候，常见会有如下⼀些场景：
1、构造⽆参函数的返回
/**
* 测试⽆参数函数mock
*/
@Test(priority=0)
public void testReturnDirect()
{
String mocked = "mocked Return";
Demo demo = Mockito.mock(Demo.class);
Mockito.when(demo.methodNoParameters()).thenReturn(mocked);
Assert.assertEquals(demo.methodNoParameters(), mocked);
}
2、构造有基本类型作为参数的返回
/**
* 测试任意基本类型参数函数mock
*/
@Test(priority=1)
public void testMethodWithParameter()
{
String word= "mocked Return";
Demo demo = Mockito.mock(Demo.class);
Mockito.when(demo.speak(Mockito.anyString())).thenReturn(word);
Assert.assertEquals(demo.speak("你好"), word);
}
3、构造有基本类型作为参数，但是只针对特定参数输⼊才mock返回值
/**
* 测试特定参数mock
*/
@Test(priority=2)
public void testMethodWithSpecificParameter()
{
String word= "mocked Return";
Demo demo = Mockito.mock(Demo.class);
Mockito.when(demo.speak(Mockito.matches(".*⼤爷$"))).thenReturn(word);
Assert.assertEquals(demo.speak("隔壁李⼤爷"), word);
}
4、构造⾃定义类作为函数参数的返回，这种情况稍微复杂⼀些，需要实现⼀个matcher类/**
* 测试⾃定义类型参数的mock
*/
@Test(priority=3)
public void testMethodWithCustomParameter()
{
String word= "mocked Return";
Demo demo = Mockito.mock(Demo.class);
Mockito.when(demo.methodCustomParameters(Mockito.argThat(new IsParameterClass()), Mockito.anyString())).thenReturn(word);
Assert.assertEquals(demo.methodCustomParameters(new ParameterClass(), "你猜"), word);
}
//⾃定义⼀个与之匹配的matcher类
class IsParameterClass extends ArgumentMatcher<ParameterClass> {
public boolean matches(Object para) {
return para.getClass() == ParameterClass.class;
}
}
5、构造null返回
/**
* 测试mock的函数返回null
*/
@Test(priority=4)
public void testMethodWithReturnNull()
{
String word= "mocked Return";
Demo demo = Mockito.mock(Demo.class);
Mockito.when(demo.speak(Mockito.anyString())).thenReturn(null);
Assert.assertNotEquals(demo.speak("你猜"), word);
}
6、构造mock的函数抛出异常，当然我们可以在testng中设置expectedExceptions以显⽰声明会抛出指定类型的异常，这样该条case执⾏的时候就会成功
/**
* 测试mock的函数抛出异常
*/
@Test(expectedExceptions=org.mockito.exceptions.base.MockitoException.class,priority=5)
public void testMethodReturnException()
{
String word= "mocked Return";
Demo demo = Mockito.mock(Demo.class);
Mockito.when(demo.speak(Mockito.anyString())).thenThrow(new Exception());
demo.speak("你猜");
}
7、某些反复调⽤，我们希望对于每次调⽤都返回不同的mock值
/**
* 测试mock的不同次调⽤返回不同的值
*/
@Test(priority=6)
public void testMethodMultiDiffReturn()
{
String word= "mocked Return 0";
String word1= "mocked Return 1";
Demo demo = Mockito.mock(Demo.class);
Mockito.when(demo.speak(Mockito.anyString())).thenReturn(word).thenReturn(word1);
Assert.assertEquals(demo.speak("你猜"), word);
Assert.assertEquals(demo.speak("你猜"), word1);
}
8、验证函数执⾏是否经过了mock
/**
* 验证⽅法是否被mock且是否为所执⾏的参数调⽤
*/
@Test(expectedExceptions= org.mockito.exceptions.misusing.NotAMockException.class,priority=7)
public void testMockedMethodRun()
{
String word= "mocked Return";
Demo demo = Mockito.mock(Demo.class);
Mockito.when(demo.speak(Mockito.anyString())).thenReturn(word);
Assert.assertEquals(demo.speak("你猜"), word);
Mockito.verify(demo.speak("你猜"));
//下⾯这个参数的⽅法调⽤并没有被执⾏过，所以会抛出NotAMockException的异常
Mockito.verify(demo.speak("nicai"));
}
如果对于上⾯的反复使⽤Mockito.when***的写法很厌烦的话，就直接静态导⼊org.mockito.Mockito.*即可。

当然，mockito的作⽤也不仅仅如上⾯，更详细的使⽤可以参考它很详细的帮助⽂档：。