为什么bean无法在junit测试环境中创建？

Question

我正在尝试为我的spring应用程序创建Junit测试。我有基于注释的配置，没有xmls。当我运行测试时，我收到以下错误：

java.lang.IllegalStateException: Failed to load ApplicationContext
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)
    at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:117)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
    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:191)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in com.library.config.DataConfig: Invocation of init method failed; nested exception is java.lang.NoSuchMethodError: javax.persistence.spi.PersistenceUnitInfo.getValidationMode()Ljavax/persistence/ValidationMode;

这是我的简单测试类：

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { WebConfig.class, DataConfig.class })
public class BookTest {

    @Test
    public void testSayHello() {
        Assert.assertEquals("Hello world!", "Hello world!");
    }
}

这是我的DataConfig：

@Configuration
@EnableJpaRepositories(basePackages = { "com.library.repositories" })
@ComponentScan("com.library.entities, com.library.services")
public class DataConfig {

    @Bean
    JpaTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactory);
        return transactionManager;
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(DataSource dataSource, Environment env) {
        LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
        entityManagerFactoryBean.setDataSource(dataSource);
        entityManagerFactoryBean.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
        entityManagerFactoryBean.setPackagesToScan("com.library.entities");
        entityManagerFactoryBean.setJpaProperties(hibernateProperties());

        return entityManagerFactoryBean;
    }

    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost/library");
        dataSource.setUsername("root");
        dataSource.setPassword("root");

        return dataSource;
    }

    final Properties hibernateProperties() {
        final Properties hibernateProperties = new Properties();
        hibernateProperties.setProperty(AvailableSettings.SHOW_SQL, "true");
        hibernateProperties.setProperty(AvailableSettings.HBM2DDL_AUTO, "update");
        return hibernateProperties;
    }

}

和WebConfig.class：

@Configuration
@EnableWebMvc
@ComponentScan("com.library.controllers")
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/resources/**")
                        .addResourceLocations("/resources/");
    }

    @Bean
    public InternalResourceViewResolver viewResolver() {
        InternalResourceViewResolver viewResolver =
                        new InternalResourceViewResolver();
        viewResolver.setViewClass(JstlView.class);
        viewResolver.setPrefix("/WEB-INF/views/");
        viewResolver.setSuffix(".jsp");
        return viewResolver;
    }

}

为什么它不起作用？该应用程序在服务器上正常运行。

P.S：如果要考虑兼容性，我的hibernate-core版本为5.2.2.FINAL和spring-test 4.3.3.RELEASE。

Answer 1

每次看到NoSuchMethodError时，这意味着您的类路径中存在不兼容的库版本。您仅在测试中遇到这种情况这一事实可能意味着您具有冲突的测试范围依赖项，或者该依赖项具有与您的编译范围依赖项冲突的自身传递依赖项。

在IDE中，您可以搜索课程 - 您应该能够在不同的jar中找到PersistenceUnitInfo的多个副本。其中一个与Spring版本不兼容。

或者，您可以在测试和编译范围中定义多个版本的Spring。

Maven命令可以帮助您调试：

• mvn dependency:tree
• mvn help:effective-pom

Answer 2

首先，使用@WebAppConfiguration注释您的测试类，如下所示：

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.WebAppConfiguration;

@WebAppConfiguration
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { WebConfig.class, DataConfig.class })
public class BookTest {

    @Test
    public void testSayHello() {
        Assert.assertEquals("Hello world!", "Hello world!");
    }
}

接下来，验证pom.xml中的依赖项，因为错误显示版本不兼容，因此在加载应用程序上下文时无法创建entityManagerFactory bean：

  

创建名为'entityManagerFactory'的bean时出错   com.library.config.DataConfig：调用init方法失败;   嵌套异常是java.lang.NoSuchMethodError：   javax.persistence.spi.PersistenceUnitInfo.getValidationMode（）Ljavax /持久/ ValidationMode;

对我来说，依赖性工作：

<properties>
        <spring.version>4.3.3.RELEASE</spring.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.2.2.Final</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>1.10.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

您可以找到解决方案源代码here。