(1). 概述
前几天,稍微研究了下Junit,是因为IDEA(Eclipse)有插件,会回调Junit的单元测试,那么:Spring是如何与Junit进行整合的呢?
答案就在:org.springframework.test.context.junit4.SpringRunner里.
(2). SpringApplicationTest
查看简单的测试案例.
// 1. RunWith会被IDEA回调执行
@RunWith(SpringRunner.class)
// 2. SpringRunner内部会通过反射获得当前类(SpringApplicationTest)的所有(注解)信息,并创建Web容器.
@SpringBootTest(classes = {HelloController.class, Conf.class})
public class SpringApplicationTest {
@Autowired
private IUserService userService;
@Test
public void testHello() {
System.out.println("*************************testHello");
}
}
(3). SpringRunner
很简单,直接调用了父类:SpringJUnit4ClassRunner
// 1. 注意是final,所以,我们自己不能继承于,得继承于:SpringJUnit4ClassRunner
public final class SpringRunner
// *****************************************************
// 2. SpringJUnit4ClassRunner
// *****************************************************
extends SpringJUnit4ClassRunner {
// 1. clazz = help.lixin.test.SpringApplicationTest
public SpringRunner(Class<?> clazz) throws InitializationError {
super(clazz);
} // end
}
(4). SpringJUnit4ClassRunner
package org.springframework.test.context.junit4;
public class SpringJUnit4ClassRunner
// ***********************************************************
// 1. 在前面分析过:BlockJUnit4ClassRunner是Junit的核心类,会被IDEA或者Maven插件回调.
// ***********************************************************
extends BlockJUnit4ClassRunner {
private final TestContextManager testContextManager;
// clazz = help.lixin.test.SpringApplicationTest
public SpringJUnit4ClassRunner(Class<?> clazz) throws InitializationError {
super(clazz);
if (logger.isDebugEnabled()) {
logger.debug("SpringJUnit4ClassRunner constructor called with [" + clazz + "]");
}
ensureSpringRulesAreNotPresent(clazz);
// **********************************************************
// 2. 创建:TestContextManager
// **********************************************************
this.testContextManager = createTestContextManager(clazz);
} // end SpringJUnit4ClassRunner
// 3. 创建:TestContextManager实例
protected TestContextManager createTestContextManager(Class<?> clazz) {
return new TestContextManager(clazz);
} // end createTestContextManager
}
(5). TestContextManager
public class TestContextManager {
private final TestContext testContext;
public TestContextManager(Class<?> testClass) {
this(
// ******************************************************************
// 2. 解析@BootstrapWith(SpringBootTestContextBootstrapper.class)
// ******************************************************************
BootstrapUtils.resolveTestContextBootstrapper(
// ******************************************************************
// 1. 创建BootstrapContext
// ******************************************************************
BootstrapUtils.createBootstrapContext(testClass)
)
);
}// end TestContextManager
static BootstrapContext createBootstrapContext(Class<?> testClass) {
// 1.1 创建:CacheAwareContextLoaderDelegate cacheAwareContextLoaderDelegate --> DefaultCacheAwareContextLoaderDelegate
CacheAwareContextLoaderDelegate cacheAwareContextLoaderDelegate = createCacheAwareContextLoaderDelegate();
Class<? extends BootstrapContext> clazz = null;
try {
// DEFAULT_BOOTSTRAP_CONTEXT_CLASS_NAME --> org.springframework.test.context.support.DefaultBootstrapContext
clazz = (Class<? extends BootstrapContext>) ClassUtils.forName(DEFAULT_BOOTSTRAP_CONTEXT_CLASS_NAME, BootstrapUtils.class.getClassLoader());
Constructor<? extends BootstrapContext> constructor = clazz.getConstructor(Class.class, CacheAwareContextLoaderDelegate.class);
if (logger.isDebugEnabled()) {
logger.debug(String.format("Instantiating BootstrapContext using constructor [%s]", constructor));
}
// 1.2 创建DefaultBootstrapContext对象,包裹着:被测试的类和DefaultCacheAwareContextLoaderDelegate
return BeanUtils.instantiateClass(constructor, testClass, cacheAwareContextLoaderDelegate);
}
catch (Throwable ex) {
throw new IllegalStateException("Could not load BootstrapContext [" + clazz + "]", ex);
}
}// end createBootstrapContext
private static CacheAwareContextLoaderDelegate createCacheAwareContextLoaderDelegate() {
Class<? extends CacheAwareContextLoaderDelegate> clazz = null;
try {
// DEFAULT_CACHE_AWARE_CONTEXT_LOADER_DELEGATE_CLASS_NAME --> org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate
clazz = (Class<? extends CacheAwareContextLoaderDelegate>) ClassUtils.forName(DEFAULT_CACHE_AWARE_CONTEXT_LOADER_DELEGATE_CLASS_NAME, BootstrapUtils.class.getClassLoader());
if (logger.isDebugEnabled()) {
logger.debug(String.format("Instantiating CacheAwareContextLoaderDelegate from class [%s]",
clazz.getName()));
}
// 1.1.1 创建:DefaultCacheAwareContextLoaderDelegate的实例
return BeanUtils.instantiateClass(clazz, CacheAwareContextLoaderDelegate.class);
}
catch (Throwable ex) {
throw new IllegalStateException("Could not load CacheAwareContextLoaderDelegate [" + clazz + "]", ex);
}
} // end createCacheAwareContextLoaderDelegate
static TestContextBootstrapper resolveTestContextBootstrapper(BootstrapContext bootstrapContext) {
Class<?> testClass = bootstrapContext.getTestClass();
Class<?> clazz = null;
try {
// ******************************************************************
// 3. 解析被测试类上的:@BootstrapWith(SpringBootTestContextBootstrapper.class)
// ******************************************************************
clazz = resolveExplicitTestContextBootstrapper(testClass);
if (clazz == null) {
// 4. 创建默认的Context
clazz = resolveDefaultTestContextBootstrapper(testClass);
}
if (logger.isDebugEnabled()) {
logger.debug(String.format("Instantiating TestContextBootstrapper for test class [%s] from class [%s]",
testClass.getName(), clazz.getName()));
}
// ****************************************************************************
// 5. 初始化,实际上可以理解为:Spring的容器了
// org.springframework.boot.test.context.SpringBootTestContextBootstrapper
// ****************************************************************************
TestContextBootstrapper testContextBootstrapper =
BeanUtils.instantiateClass(clazz, TestContextBootstrapper.class);
testContextBootstrapper.setBootstrapContext(bootstrapContext);
return testContextBootstrapper;
} catch (IllegalStateException ex) {
throw ex;
} catch (Throwable ex) {
throw new IllegalStateException("Could not load TestContextBootstrapper [" + clazz +
"]. Specify @BootstrapWith's 'value' attribute or make the default bootstrapper class available.",
ex);
}
} // end resolveTestContextBootstrapper
// 判断类上是否有注解@WebAppConfiguration,如果有这个注解,则解析成:WebTestContextBootstrapper
// 否则,解析成:DefaultTestContextBootstrapper
private static Class<?> resolveDefaultTestContextBootstrapper(Class<?> testClass) throws Exception {
ClassLoader classLoader = BootstrapUtils.class.getClassLoader();
// WEB_APP_CONFIGURATION_ANNOTATION_CLASS_NAME --> org.springframework.test.context.web.WebAppConfiguration
AnnotationAttributes attributes = AnnotatedElementUtils.findMergedAnnotationAttributes(testClass, WEB_APP_CONFIGURATION_ANNOTATION_CLASS_NAME, false, false);
if (attributes != null) {
// DEFAULT_WEB_TEST_CONTEXT_BOOTSTRAPPER_CLASS_NAME --> org.springframework.test.context.web.WebTestContextBootstrapper
return ClassUtils.forName(DEFAULT_WEB_TEST_CONTEXT_BOOTSTRAPPER_CLASS_NAME, classLoader);
}
// DEFAULT_TEST_CONTEXT_BOOTSTRAPPER_CLASS_NAME --> org.springframework.test.context.support.DefaultTestContextBootstrapper
return ClassUtils.forName(DEFAULT_TEST_CONTEXT_BOOTSTRAPPER_CLASS_NAME, classLoader);
} // end resolveDefaultTestContextBootstrapper
}
(6). SpringBootTestContextBootstrapper
我比较关心Properties的处理(如何让它与Apollo/Nacos整合),没想到的是Spring不会读取配置文件(application.properties),而是要求把配置文件附加在注解上
// @SpringBootTest(classes = {HelloController.class, Conf.class}, properties = {"test.key=world"})
public class SpringBootTestContextBootstrapper extends DefaultTestContextBootstrapper {
public TestContext buildTestContext() {
TestContext context = super.buildTestContext();
verifyConfiguration(context.getTestClass());
WebEnvironment webEnvironment = getWebEnvironment(context.getTestClass());
if (webEnvironment == WebEnvironment.MOCK
&& deduceWebApplicationType() == WebApplicationType.SERVLET) {
context.setAttribute(ACTIVATE_SERVLET_LISTENER, true);
}
else if (webEnvironment != null && webEnvironment.isEmbedded()) {
context.setAttribute(ACTIVATE_SERVLET_LISTENER, false);
}
return context;
}
protected void processPropertySourceProperties(
MergedContextConfiguration mergedConfig,
List<String> propertySourceProperties) {
Class<?> testClass = mergedConfig.getTestClass();
// 读取注解上的配置
// @SpringBootTest(classes = {HelloController.class, Conf.class}, properties = {"test.key=world"})
String[] properties = getProperties(testClass);
if (!ObjectUtils.isEmpty(properties)) {
// 把所有的配置合并在一起
propertySourceProperties.addAll(0, Arrays.asList(properties));
}
// 判断是否为:RANDOM_PORT
if (getWebEnvironment(testClass) == WebEnvironment.RANDOM_PORT) {
// 定义随机端口.
propertySourceProperties.add("server.port=0");
}
}
}
(7). 总结
Spring在单元测试方面还是比较用心的,只是,代码有一点点乱!
