spring框架--spring注解开发

//表示该类是一个Spring的配置类，用来存放spring的配置信息
@Configuration    
public class SpringConfiguration {
    
}

//用于指定 Spring 在初始化容器时要扫描的包。   
//相当于xml配置时的`<context:component-scan base-package="com.itheima"/>`

@Configuration
@ComponentScan("com.itheima")        
public class SpringConfiguration {
    
}

//用于导入其他的配置类 
//相当于xml配置时的`<import resource="classpath:applicationContext-dao.xml"/>`

@Configuration
@ComponentScan("com.itheima")
@Import({DataSourceConfiguration.class})
public class SpringConfiguration {
}

//用于properties配置文件
//相当于xml配置时的`<context:property-placeholder location="classpath:jdbc.properties"/>`

@PropertySource("classpath:jdbc.properties")
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;
}

//使用在方法上，Spring会自动执行该方法，并把方法返回的对象，存储在spring容器中

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

@Test
public void testAnnoConfiguration() throws Exception {
    //根据配置类SpringConfiguration.class，获取Spring的核心容器
    ApplicationContext ac = 
            new AnnotationConfigApplicationContext(SpringConfiguration.class);
    
    //获取userService对象
    UserService userService = (UserService)ac.getBean("userService");
    userService.save();
    
    //获取dataSource对象
    DataSource dataSource = (DataSource)ac.getBean("dataSource");
    Connection connection = dataSource.getConnection(); 
    System.out.println(connection);
}

 1 　　　　　<dependency>
 2             <groupId>c3p0</groupId>
 3             <artifactId>c3p0</artifactId>
 4             <version>0.9.1.2</version>
 5         </dependency>
 6         <dependency>
 7             <groupId>mysql</groupId>
 8             <artifactId>mysql-connector-java</artifactId>
 9             <version>5.1.47</version>
10         </dependency>
11         <dependency>
12             <groupId>org.springframework</groupId>
13             <artifactId>spring-jdbc</artifactId>
14             <version>5.0.5.RELEASE</version>
15         </dependency>

 1 public interface UserService {
 2     public List<User> findAll() throws SQLException;
 3 }
 4 
 5 
 6 
 7 @Service
 8 public class UserService implements com.itcast.Service.UserService {
 9 
10     @Autowired//注解注入
11     private UserDao userDao;
12 
13     public List<User> findAll() throws SQLException {
14         List<User> users = userDao.findAll();
15         return users;
16     }
17 }

//接口：
public interface UserDao {
    public List<User> findAll() throws SQLException;
}


//实现类：
@Repository
public class UserDaoImpl implements UserDao {

    @Autowired
    private DataSource dataSource;

    public List<User> findAll() throws SQLException {
        JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
        List<User> users = jdbcTemplate.query("select * from userform", new BeanPropertyRowMapper<User>(User.class));
        return users;
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

        <!--开启注解扫描-->
    <context:component-scan base-package="com.itcast"></context:component-scan>

    <!--配置C3P0链接池-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
        <property name="jdbcUrl" value="jdbc:mysql:///daynov06"></property>
        <property name="user" value="root"></property>
        <property name="password" value="root"></property>
    </bean>
    
</beans>

 1 public class Demo1 {
 2     public static void main(String[] args) throws SQLException {
 3 
 4         //读取配置文件
 5         ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
 6         //从spring中获取目标对象
 7         UserService bean = app.getBean(UserService.class);
 8         //调用方法
 9         List<User> all = bean.findAll();
10         for (User user : all) {
11             System.out.println(user);
12         }
13 
14     }
15 }