SpringBoot项目下的JUnit测试

在SpringBoot项目里，要编写单元测试用例，需要依赖4个jar。一个是最基本的JUnit，然后是spring-test和spring-boot-test。

        <!--test-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.1.9.RELEASE</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
            <version>2.1.7.RELEASE</version>
            <scope>test</scope>
        </dependency>

如果在运行testcase时，遇到如下问题，那么，原因是因为没有引入spring-core包（错误消息里说的很明白了，见其中的springframework/core）

java.lang.NoSuchMethodError: org.springframework.core.type.AnnotationMetadata.introspect(Ljava/lang/Class;)Lorg/springframework/core/type/AnnotationMetadata;

    at org.springframework.beans.factory.annotation.AnnotatedGenericBeanDefinition.<init>(AnnotatedGenericBeanDefinition.java:58)
    at org.springframework.context.annotation.AnnotatedBeanDefinitionReader.doRegisterBean(AnnotatedBeanDefinitionReader.java:253)
    at org.springframework.context.annotation.AnnotatedBeanDefinitionReader.registerBean(AnnotatedBeanDefinitionReader.java:147)
    at org.springframework.context.annotation.AnnotatedBeanDefinitionReader.register(AnnotatedBeanDefinitionReader.java:137)
    at org.springframework.boot.BeanDefinitionLoader.load(BeanDefinitionLoader.java:156)
    at org.springframework.boot.BeanDefinitionLoader.load(BeanDefinitionLoader.java:135)
    at org.springframework.boot.BeanDefinitionLoader.load(BeanDefinitionLoader.java:127)
    at org.springframework.boot.SpringApplication.load(SpringApplication.java:687)
    at org.springframework.boot.SpringApplication.prepareContext(SpringApplication.java:385)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:311)
    at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:120)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:99)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:117)
    at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:108)
    at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:190)
    at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:132)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:246)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:227)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:289)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:291)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:246)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$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)

依赖spring-core包：

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.2.0.RELEASE</version>
        </dependency>

如下是一个testcase示例。其中

@RunWith是JUnit的一个运行器。@RunWith(JUnit4.class)就是指用JUnit4来运行；@RunWith(SpringJUnit4ClassRunner.class),让测试运行于Spring测试环境

import com.alibaba.fastjson.JSON;
import org.apache.dubbo.config.annotation.Reference;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class CarSignatureServiceTest {

    @Reference(url = "dubbo://localhost:20880")
    private CarSignatureService carSignatureService;

    @Test
    public void getSignedCarList(){
        List<ServiceOrderVO> list = carSignatureService.getSignedCarList(new ServiceOrderVO());
        System.out.println(JSON.toJSONString(list));
    }
}