@Configuration 类后 SpringbootTest 失败：创建名称为“datasource”的 bean 时出错答案

【问题标题】：SpringbootTest failing after @Configuration class: Error creating bean with name 'datasource'@Configuration 类后 SpringbootTest 失败：创建名称为“datasource”的 bean 时出错
【发布时间】：2021-07-27 14:14:34
【问题描述】：

我正在尝试执行几个之前运行良好的测试用例。我最近在下面添加了一个配置类：

@Configuration
public class DBConfig {

@Value("${spring.datasource.username:}")
private String username;

@Value("${spring.datasource.url:}")
private String url;

@Bean
@DependsOn("passwordProvider")
public DataSource datasource(PasswordProvider passwordProvider) {
    return DataSourceBuilder
            .create()
            .url(url)
            .username(username)
            .password(new String(passwordProvider.getKeyByName("DB_PASSWORD").getKey()))
            .build();
}
 }

现在，我所有的 SpringbootTests 都失败了，但有以下例外：

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.cloud.autoconfigure.RefreshAutoConfiguration$JpaInvokerConfiguration': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.jdbc.DataSourceInitializerInvoker': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'datasource' defined in class path resource [com/example/configuration/DBConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'datasource' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:160)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:422)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1778)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:602)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1154)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:908)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:769)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:426)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:326)
at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:123)

知道如何修复它吗？我不想在 test.properties 中提供 passwordProvider 配置。

【问题讨论】：

正如您自己的堆栈所说，Factory method 'datasource' threw exception; nested exception is java.lang.NullPointerException。您的 bean 依赖于 passwordProvider，但您没有在 @Configuration 中显示任何具有该名称的 bean，因此可能是您没有初始化它，因此在 passwordProvider.getKeyByName(...) 上有一个空指针。无论如何，无法说出您在问题中提供的内容，我们只能猜测。
@MatteoNNZ passwordProvider bean 是通过在属性文件中提供配置来创建的。对于测试课程，我认为我不应该那样做。我只是想执行测试用例而不需要创建数据源。
在这种情况下，您需要一个测试配置文件，它以不同于生产的方式构建配置（例如不创建 bean，或创建模拟 bean）。查看更多about Spring profiles
看来您正在重新声明内置配置。让DataSourceAutoConfiguration 完成它的工作。

标签： java spring-boot unit-testing

【解决方案1】：

只需在 Spring Boot 测试中提及，它就会加载您的配置类：

@RunWith(SpringRunner.class)
@SpringBootTest(classes = {DBConfig.class})
public class SpringBootIntegrationTest {
    // ...
}

【讨论】：