02-2SpringIoC新注解开发

①创建spring配置类

@Configuration  //相当于之前的配置文件
@ComponentScan("com.*")  //初始化容器扫描的包
@import(DataSourceConfiguration.class) //导入数据源配置类
public class SpringConfigration {
}

②创建数据库连接池信息

创建jdbc.properties配置文件

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/nie
jdbc.username=root
jdbc.password=root

创建数据库连接配置类

@PropertySource("classpath:jdbc.properties")
@Component("dataSourceConfiguration")
public class DataSourceConfiguration {

    @Value("${jdbc.driver}")
    private String driver;
    @Value("${jdbc.url}")
    private String url;
    @Value("${jdbc.username}")
    private String username;
    @Value("${jdbc.password}")
    private String password;

    @Bean("dataSource")
    public DataSource getDataSource() throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass(driver);
        dataSource.setJdbcUrl(url);
        dataSource.setUser(username);
        dataSource.setPassword(password);
        return dataSource;
    }

③测试是否连接成功

  @Test
    public void TestConfig() throws SQLException, PropertyVetoException {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(SpringConfigration.class);
        DataSourceConfiguration dataSource = (DataSourceConfiguration) context.getBean("dataSourceConfiguration");
        DataSource dataSource1 = dataSource.getDataSource();
        System.out.println(dataSource1.getConnection());
        DataSource dataSourceBean = (DataSource)context.getBean("dataSource");
        System.out.println(dataSourceBean.getConnection());
    }

在测试类中，每个测试方法都有以下两行代码：

 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
 UserDao userDao = (UserDao) context.getBean("userDao");

这两行代码的作用是获取容器，如果不写的话，直接会提示空指针异常。

Spring5支持整合SpringJunit的包，让SpringJunit负责创建Spring容器，但是需要将配置文件的名称告诉它，然后将需要进行测试Bean直接在测试类中进行注入

①导入spring集成Junit的坐标

        
            org.springframework
            spring-test
            5.1.9.RELEASE
        
        
            junit
            junit
            4.13
            test
        

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {SpringConfigration.class})
//@ContextConfiguration("classpath:applicationContext.xml")
public class SpringJunitTest {

    @Autowired
    private UserService userService;

    @Test
    public void test01(){
        userService.save();
    }
}