PowerMock单元测试

      在Java程序的单元测试中常用的mock工具有Mockito和EasyMock。但是这两种mock工具都无法实现对静态、final、私有方法或类的mock。因此有了功能强大的PowerMock工具。PowerMock并不是一个独立、全新的工具而是在Mockito和EasyMock的基础上进行的扩展，它分别有针对Mockito级EasyMock的扩展实现。本文主要介绍PowerMock的常见用法：

1.pom依赖

1<dependency>
2	<groupId>junit</groupId>
3	<artifactId>junit</artifactId>
4        <version>4.10<version>
5	<scope>test</scope>
6</dependency>        
7<dependency>
8        <groupId>org.powermock</groupId>
9        <artifactId>powermock-module-junit4</artifactId>
10        <version>1.6.3</version>
11        <scope>test</scope>
12</dependency>    
13<dependency>    
14        <groupId>org.powermock</groupId>    
15        <artifactId>powermock-api-mockito</artifactId>    
16        <version>1.6.3</version>    
17        <scope>test</scope>    
18</dependency>

2.基本用法

2.1 测试类加上必要的注解

@RunWith(PowerMockRunner.class)
@PrepareForTest({ExtensionLoader.class,Configs.class})  //静态类，测试类本身（需要mock构造方法时）
@PowerMockIgnore("javax.management.*")

2.2 mock基本对象

测试 convert.convertAndHanlder(method,ref,bead)方法

1@Mock
2Convert convert;
3
4
5when(convert.convertAndHanlder(eq(method),eq(ref),eq(bead))).thenReturn(bead);

2.3 mock无返回值的方法

1@Mock
2ProviderComposeConfig providerComposeConfig;
3
4
5doNothing().when(providerComposeConfig).putSync(eq(providerConfig));

 2.4 mock方法执行异常场景

1@Mock
2ProviderComposeConfig providerComposeConfig;
3
4doThrow(new Exception("执行失败")).when(providerComposeConfig).putSync(eq(providerConfig));

2.5 mock 静态方法

 测试Configs.getConfig（ProviderComposeConfig.class）方法

前提：@PrepareForTest注解中添加该类：ProviderComposeConfig.class

1@Mock
2ProviderComposeConfig configs;
3
4
5PowerMockito.mockStatic(Configs.class);
6when(Configs.getConfig(eq(ProviderComposeConfig.class))).thenReturn(configs);

mock无返回值的static方法

// "xxxUtil" 是类名 // "xxxStaticMethod" 是 static 方法的方法名 // 这里假设 "xxxStaticMethod" 需要两个参数，一个是 int 型，一个是 String 型 PowerMockito.doNothing().when(xxxUtil.class, "xxxStaticMethod", 1，"mysql");

mock可变参数传递

1public class Demo {
2	public static void test(String... args) {
3		System.out.println(args);
4	}
5}

 测试方法：

1@RunWith(PowerMockRunner.class)
2@PrepareForTest({Demo.class})
3@PowerMockIgnore("javax.management.*")
4public class DemoTest {
5	
6	@Test
7	public void test() throws Exception {
8		PowerMockito.mockStatic(Demo.class);
9		PowerMockito.doNothing().when(Demo.class,"test",eq("liu1"),eq("liu2"));
10		Demo.test("liu1","liu2");
11	}
12	
13}

 2.6 mock 构造方法

前提：@PrepareForTest注解中添加该类：HookContext.class

1@Mock
2HookContext context; 
3 
4
5//无参构造
6PowerMockito.whenNew(HookContext.class).withNoArguments().thenReturn(context);
7
8//有参构造
9PowerMockito.whenNew(HookContext.class).withArguments(anystring()).thenReturn(context);

 ③完成实例

被测试类：

1public class HandlerHook {
2
3	public final static String id = "handler";
4
5	@Override
6	public Bead doCall(HookContext context, Bead bead, AccessId id) throws Throwable {
7		ProviderComposeConfig configs = Configs.getConfig(ProviderComposeConfig.class);
8		ProviderConfig config = configs == null ? null : configs.get(id);
9
10		if (config == null) {
11			// 即没有该服务，1.本地调用 2.客户端信息有误，访问IP:PORT 却没有服务
12			return null;
13		}
14
15		// 拿到转换器，调用
16		Convert convert = ExtensionLoader.getExtensionLoader(Convert.class).getExtensionById(ConvertProcessor.id);
17		return convert.convertAndHanlder(config.getMethod(), config.getRef(), bead);
18	}
19
20}

 测试类：

1@RunWith(PowerMockRunner.class)
2@PrepareForTest({ExtensionLoader.class,Configs.class})
3@PowerMockIgnore("javax.management.*")
4public class HandlerHookTest {
5
6	@Mock
7	HookContext hookContext;
8	
9	@Mock
10	Bead bead;
11	
12	@Mock
13	AccessId accessId;
14	
15	@Mock
16	ExtensionLoader<Convert> extensionLoader;
17	
18	@Mock
19	ProviderComposeConfig configs;
20	
21	@Mock
22	ProviderConfig config;
23	
24	@Mock
25	Method method ;
26	
27	@Mock
28	Object ref;
29	
30	@Mock
31	Convert convert;
32	
33	private HandlerHook handlerHook = new HandlerHook();
34	
35	@Test
36	public void doCall() throws Throwable {
37		PowerMockito.mockStatic(Configs.class);
38		when(Configs.getConfig(eq(ProviderComposeConfig.class))).thenReturn(configs);
39		when(configs.get(eq(accessId))).thenReturn(config);
40		
41		PowerMockito.mockStatic(ExtensionLoader.class);
42		when(ExtensionLoader.getExtensionLoader(eq(Convert.class))).thenReturn(extensionLoader);
43		when(extensionLoader.getExtensionById(eq("map"))).thenReturn(convert);
44		when(config.getMethod()).thenReturn(method);
45		when(config.getRef()).thenReturn(ref);
46		
47		when(convert.convertAndHanlder(eq(method),eq(ref),eq(bead))).thenReturn(bead);
48		assertEquals(bead, handlerHook.doCall(hookContext, bead, accessId));
49	}
50	
51}