为什么在junit测试环境中无法创建bean？

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 xml。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!");
    }
}

这是我的数据配置：

@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;
    }

}

还有 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运行正常。

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

Answer 1

每次你看到NoSuchMethodError 这意味着你的类路径中有不兼容的库版本。您仅在测试中遇到这种情况的事实可能意味着您有一个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传递依赖项。

在您的 IDE 中，您可以搜索类 - 您应该能够在不同的 jar 中找到 PersistenceUnitInfo 的多个副本。其中之一与 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。

可以帮助您调试的 Maven 命令：

• 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，验证您在 pom.xml 中的依赖关系，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：

创建名称为“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/persistence/ValidationMode;

对我来说，以下依赖项有效：

<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。