H2内存数据库实现Dao层单元测试

• 为什么要使用H2数据库：

  • 在写DAO层的单元测试时，我们往往会遇到一个问题，测试用例所依赖的数据库数据被修改或删除了，或者在一个新的环境下所依赖的数据库不存在，导致单元测试无法通过，进而构建失败。
  • 在这种情况下，使用H2内存数据库来模拟数据库环境是一个很好的解决方案：这种数据库可以伴随着我们的单侧用例启动而启动，运行结束即关闭，对数据不会进行持久化的操作；

操作步骤：

1.引入pom.xml文件依赖

• </dependency>
• <dependency>
  • <groupId>com.h2database</groupId>
  • <artifactId>h2</artifactId>
  • <scope>test</scope>

• 2.配置JDBC.properties:

  • jdbc.gaotu.url=jdbc:h2:mem:gaotu;MODE=MYSQL;DB_CLOSE_DELAY=-1
    • jdbc:h2:mem:  表示使用的数据库是H2内存数据库；
    • gaotu：表示数据库的命名；
    • MODE=MYSQL 表示我们的数据库以mySql的形式运行
    • DB_CLOSE_DELAY=-1 设置数据库延时关闭，给代码执行预留时间

• 3.写sql；（这里的sql用的是H2数据库的sql语句）

  • schema.sql
  • data.sql

• 4.数据源配置：

  • 1）文件如下：

    • package com.gaotu.test.config;
      import org.apache.ibatis.session.SqlSessionFactory;
      import org.mybatis.spring.SqlSessionFactoryBean;
      import org.mybatis.spring.annotation.MapperScan;
      import org.springframework.beans.factory.annotation.Autowired;
      import org.springframework.beans.factory.annotation.Qualifier;
      import org.springframework.beans.factory.annotation.Value;
      import org.springframework.context.annotation.Bean;
      import org.springframework.context.annotation.Configuration;
      import org.springframework.context.annotation.PropertySource;
      import org.springframework.core.io.ClassPathResource;
      import org.springframework.core.io.Resource;
      import org.springframework.jdbc.datasource.DataSourceTransactionManager;
      import org.springframework.jdbc.datasource.DriverManagerDataSource;
      
      import org.springframework.jdbc.datasource.init.DatabasePopulator;
      import org.springframework.jdbc.datasource.init.DatabasePopulatorUtils;
      import org.springframework.jdbc.datasource.init.ResourceDatabasePopulator;
      import org.springframework.transaction.PlatformTransactionManager;
      import org.springframework.transaction.annotation.EnableTransactionManagement;
      
      import javax.sql.DataSource;
      
      @Configuration
      @EnableTransactionManagement
      @PropertySource(ignoreResourceNotFound = true, value = { "classpath:jdbc.properties" })
      @MapperScan(basePackages = { "com.gaotu.mapper",
              "com.jiazi.**.mapper","com.gaotu.**.mapper.auto" }, sqlSessionFactoryRef = "gaotuSessionFactory")
      public class GaotuDataSourceTestConfig {
      
          @Value("${jdbc.gaotu.username}")
          private String username;
      
          @Value("${jdbc.gaotu.password}")
          private String password;
      
          @Value("${jdbc.gaotu.url}")
          private String url;
      
          @Value("classpath:/db/gaotu/INIT_TABLE.sql")
          private Resource schemaScript;
      
          @Value("classpath:/db/gaotu/INIT_DATA.sql")
          private Resource dataScript;
      
      
          public DataSource gaotuDatasource() throws Exception {
              DriverManagerDataSource dataSource = new DriverManagerDataSource(url, username, password);
      
              return dataSource;
          }
      
          @Bean(name = "gaotuDatasource")
          public DataSource getDataSource() throws Exception {
              DataSource dataSource = gaotuDatasource();
              DatabasePopulatorUtils.execute(databasePopulator(), dataSource);
              return dataSource;
          }
      
          @Bean(name = "gaotuSessionFactory")
          public SqlSessionFactory sqlSessionFactoryBean(
              @Autowired @Qualifier(value = "gaotuDatasource") final DataSource dataSource) throws Exception {
              SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
              sqlSessionFactoryBean.setConfigLocation(new ClassPathResource("db/mybatis-config.xml"));
              sqlSessionFactoryBean.setDataSource(dataSource);
              return sqlSessionFactoryBean.getObject();
          }
      
          private DatabasePopulator databasePopulator() {
              final ResourceDatabasePopulator populator = new ResourceDatabasePopulator();
              populator.addScript(schemaScript);
              populator.addScript(dataScript);
              return populator;
          }
      
          @Bean(name = "gaotuTransactionManager")
          public PlatformTransactionManager gaotuTransactionManager(
              @Autowired @Qualifier(value = "gaotuDatasource") final DataSource dataSource) {
              return new DataSourceTransactionManager(dataSource);
          }
      }

    • 2)文件如下：

      • package com.gaotu.test.config;
        
        import org.springframework.context.annotation.ComponentScan;
        import org.springframework.context.annotation.Configuration;
        import org.springframework.context.annotation.PropertySource;
        
        @Configuration
        @PropertySource(value = {"classpath:application.properties"})
        @ComponentScan(basePackages = { "com.gaotu.**.dao"})
        public class DaoBasicTestConfig {
        }
        

• 5.写单侧实例：
  • 1）BaseDaoTest.java

    • package com.gaotu.test.base;
      
      import com.gaotu.test.config.DaoBasicTestConfig;
      import com.gaotu.test.config.GaotuDataSourceTestConfig;
      
      import org.junit.runner.RunWith;
      import org.springframework.test.context.ContextConfiguration;
      import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
      
      @RunWith(SpringJUnit4ClassRunner.class)
      @ContextConfiguration(classes = { DaoBasicTestConfig.class, GaotuDataSourceTestConfig.class})
      public class BaseDaoTest {}

    • 2)具体的单侧

      • package com.gaotu.order.dao.test;
        
        import com.gaotu.mapper.auto.OrderInfo;
        import com.gaotu.order.dao.OrderInfoDAO;
        import com.gaotu.test.base.BaseDaoTest;
        
        import org.junit.Assert;
        import org.junit.Test;
        
        import javax.annotation.Resource;
        
        public class OrderInfoDAOTest extends BaseDaoTest {
        
            @Resource
            private OrderInfoDAO orderInfoDAO;
        
            @Test
            public void testGetOrderInfoByOrderId() {
                final OrderInfo orderInfo = orderInfoDAO.getOrderInfoByOrderId("251996234968758");
                Assert.assertNotNull(orderInfo);
                Assert.assertEquals(251996234968758L, orderInfo.getOrderNumber().longValue());
            }
            
        }