Spring整合Junit测试，并且配置事务

分手后的思念是犯贱 2022-08-01 15:55 219阅读 0赞

## 问题 ##

很多时候我们不希望单元测试的结果玷污了数据库，玷污了我们也不希望人肉去check，我们希望它无痕迹的悄悄执行，告诉我最终结果即可。那么怎样让你的UT也具有事务功能呢？

## 预期效果 ##

我们希望能够达到这样的效果：

package me.arganzheng.study; import static org.junit.Assert.*; import org.junit.Test; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.annotation.Rollback; /** * * @author arganzheng */ public class FooServiceTest{ @Autowired private FooService fooService; @Test @Rollback(true) public void testSaveFoo() { Foo foo = new Foo(); // ... long id = fooService.saveFoo(foo); assertTrue(id > 0); } }

虽然我们插入了一条数据，但是在UT后，已经雁过无痕了。

## 解决方案 ##

在前面一篇文章[JUnit与Spring的整合——JUnit的TestCase如何自动注入Spring容器托管的对象][JUnit_Spring_JUnit_TestCase_Spring]中我们详细的介绍了Spring与Junit的整合，提到了Spring3提供了`SpringJUnit4ClassRunner`基类让我们可以很方便的接入JUnit4。

public class org.springframework.test.context.junit4.SpringJUnit4ClassRunner extends org.junit.runners.BlockJUnit4ClassRunner { ... }

它是基于事件监听机制（the listener-based test context framework），并且允许用户自定义事件监听器。默认是`org.springframework.test.context.support.DependencyInjectionTestExecutionListener`、`org.springframework.test.context.support.DirtiesContextTestExecutionListener`和`org.springframework.test.context.transaction.TransactionalTestExecutionListener`这三个事件监听器。

其中`org.springframework.test.context.support.DependencyInjectionTestExecutionListener`是实现自动注入Spring托管的bean的。而`org.springframework.test.context.transaction.TransactionalTestExecutionListener`则是实现事务管理的事件处理器：

> org.springframework.test.context.transaction.TransactionalTestExecutionListener
> 
> TestExecutionListener which provides support for executing tests within transactions by using @Transactional and @NotTransactional annotations.
> 
> Changes to the database during a test run with @Transactional will be run within a transaction that will, by default, be automatically rolled back after completion of the test; whereas, changes to the database during a test run with @NotTransactional will not be run within a transaction. Similarly, test methods that are not annotated with either @Transactional (at the class or method level) or @NotTransactional will not be run within a transaction.
> 
> Transactional commit and rollback behavior can be configured via the class-level @TransactionConfiguration and method-level @Rollback annotations. @TransactionConfiguration also provides configuration of the bean name of the PlatformTransactionManager that is to be used to drive transactions.
> 
> When executing transactional tests, it is sometimes useful to be able execute certain set up or tear down code outside of a transaction. TransactionalTestExecutionListener provides such support for methods annotated with @BeforeTransaction and @AfterTransaction.

其实我发现Spring的javadoc非常的简单明了又全面，根本不需要到处查找其他的东东，直接看javadoc和源码就可以了。这里简单概括一下：

*  `TransactionalTestExecutionListener`
    
     *  @Transactional (class-level & method-level)
     *  @NotTransactional (method-level)
     *  @TransactionConfiguration (class-level)
     *  @Rollback (method-level)
     *  @BeforeTransaction (method-level)
     *  @AfterTransaction (method-level)

注：其中 class-level即`Target(ElementType.TYPE)`，method-level即`Target(ElementType.METHOD)`。

这样我们可以如下配置：

ackage me.arganzheng.study; import org.junit.runner.RunWith; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import org.springframework.transaction.annotation.Transactional; /** * * @author arganzheng */ @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration({ "classpath:conf-spring/spring-dao.xml", "classpath:conf-spring/spring-service.xml", "classpath:conf-spring/spring-controller.xml" }) @TransactionConfiguration(transactionManager="transactionManager") //可选，默认就是这个 @Transactionnal public class BaseSpringTestCase{ }

然后我们的FooServiceTest这样写就可以拥有事务处理能力了：

package me.arganzheng.study; import static org.junit.Assert.*; import org.junit.Test; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.annotation.Rollback; /** * * @author arganzheng */ public class FooServiceTest extends BaseSpringTestCase{ @Autowired private FooService fooService; @Test // @Rollback(true) 默认就是true public void testSaveFoo() { Foo foo = new Foo(); // ... long id = fooService.saveFoo(foo); assertTrue(id > 0); } }

[JUnit_Spring_JUnit_TestCase_Spring]: http://blog.arganzheng.me/posts/junit-and-spring-integration-ioc-autowire.html