Spring注解开发Junit、JdbcTemeplate学习

1、Spring注解开发

常用原始注解

• @Controller 在web层类上实例化Bean
• @Service 在service层类上实例化Bean
• @Repository 在dao层上实例化Bean
• @Component 在通用类上实例化Bean
• @Autowired 根据类型依赖注入
• @Qualifier 跟@Autowired一起使用，可根据名称依赖注入
• @Resource 相当于@Autiwired和@Qualifier，根据名称依赖注入
• @Value 注入普通属性
• @Scope 标注Bean的作用范围
• @PostConstruct Bean的初始化方法
• @PreDestroy Bean的销毁方法

常用新注解

• @Configuration 指定Spirng的配置类
• @ComponentScan 指定Spring初始化容器时需要扫描的包
• @Bean 使用在方法上，将返回值存储到Spring容器中
• @PropertySource 用于加载properties文件
• @Import 用于导入其它包

2、案例

使用注解进行开发时，需要在applicationContext.xml中配置组件扫描

<context:component-scan base-package="cn.guixinchn"></context:component-scan>

然后使用注解@Service、@Repository 标识需要Spring实例化的类

使用@Autowired、@Qualifier进行依赖注入

@Repository("userDao")
public class UserDaoImpl implements UserDao {
    public void save() {
        System.out.println("save running....");
    }
}


@Service("userServer")
public class UserServerImpl implements UserServer {
    @Autowired
    @Qualifier("userDao")
    private UserDao userDao;
    public UserServerImpl(UserDao userDao) {
        this.userDao = userDao;
    }
    public void save() {
        userDao.save();
    }
}

使用注解充当配置文件

@Configuration
@ComponentScan("cn.guixinchn")
@PropertySource("classpath:jdbc.properties")
public class SpringConfiguration {
    @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(name="dataSource")
    public DataSource getDataSource () throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass(driver);
        dataSource.setJdbcUrl(url);
        dataSource.setUser(username);
        dataSource.setPassword(password);
        return dataSource;
    }
}

测试

    @Test
    public void test4() throws SQLException {
        //获取注解配置类的上下文对象
        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(SpringConfiguration.class);
        //拿到数据源
        DataSource dataSource = (DataSource) applicationContext.getBean("dataSource");
        //获得连接对象
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }

3、Spring集成Junit

3.1、导入spring集成Junit的坐标

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-test</artifactId>
    <version>5.0.2.RELEASE</version>
</dpendency>

3.2、使用@Runwith注解替换原来的运行期、使用@ContextConfiguration指定配置文件或配置类

3.3、使用@Autowired注入需要测试的对象、使用@Test创建测试方法进行测试

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = SpringConfiguration.class)
public class JunitTest {
    @Autowired
    private UserServer userServer;

    @Test
    public void test(){
        userServer.save();
    }
}

4、Spring框架中JdbcTemeplate的使用

4.1导入spring-jdbc和spring-tx坐标

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.0.3.RELEASE</version>
</depe
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-tx</artifactId>
    <version>5.0.3.RELEASE</version>
</dependency>

4.2创建数据库表和实体

public class Student {
    private String name;
    private int age;
    /*省略set个get方法，tostring方法*/
}

4.3让Spirng容器产生JdbcTemplate对象，并获取数据源

    <!--Spring容器加载properties文件-->
    <context:property-placeholder location="classpath:jdbc.properties"></context:property-placeholder>

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"></property>
        <property name="jdbcUrl" value="${jdbc.url}"></property>
        <property name="user" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

4.4创建测试类执行数据库操作

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class JdbcTemplateTest {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Test
    public void test1(){
        int i = jdbcTemplate.update("insert into student value (?, ?)", "张三", 18);
        System.out.println(i);
        
    }
}

4.5测试JdbcTemplate的查询操作

JdbcTemplate模板里面通过RowMapper的实现类BeanPropertyRowMapper，为我们封装实体类

    @Test
    public void queryAllTest(){
        List<Student> studentList = jdbcTemplate.query("select * from student", new BeanPropertyRowMapper<Student>(Student.class));
        System.out.println(studentList);
    }
    @Test
    public void queryOneTest(){
        Student student = jdbcTemplate.queryForObject("select * from student where name = ?", new BeanPropertyRowMapper<Student>(Student.class), "张三");
        System.out.println(student);
    }
    @Test
    public void queryCountTest(){
        Long num = jdbcTemplate.queryForObject("select count(*) from student", Long.class);
        System.out.println(num);
    }