Spring入门案例

AccountDao

public interface AccountDao {
    void saveAccount();
}

AccountDaoImpl

public class AccountDaoImpl implements AccountDao {
    public void saveAccount() {
        System.out.println("保存了账户");
    }
}

AccountService

public interface AccountService {
    void saveAccount();
}

AccountServiceImpl

public class AccountServiceImpl implements AccountService{
    private AccountDao accountDao = new AccountDaoImpl();
    public void saveAccount() {
        accountDao.saveAccount();
    }
}

bean.xml
上面有两个实体类，就配置两个bean,创建两个对象

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
    <!--把对象的创建交给bean来处理-->
    <bean id="accountService" class="com.hh.service.AccountServiceImpl"/>
    <bean id="accountDao" class="com.hh.dao.AccountDaoImpl"/>
</beans>

测试类：

public class Client {
    public static void main(String[] args) {
        ApplicationContext context =
            new ClassPathXmlApplicationContext("bean.xml");
        AccountService service = 
        	context.getBean("accountService", AccountService.class);
        AccountDao accountDao = 
        	context.getBean("accountDao", AccountDao.class);
        System.out.println(service);
        System.out.println(accountDao);
    }
}