526互联

02-DI入门案例(XML版)

发布时间 2024-01-02 17:38:51作者: belhomme

步骤

  1. 删除使用 new 的形式创建对象的代码

    public class BookServiceImpl implements BookService {
    private BookDao bookDao;

    @Override
    public void save() {
        System.out.println("book service save...");
        bookDao.save();
    }
}

  2. 提供依赖对象对应的 setter 方法

    public class BookServiceImpl implements BookService {
    private BookDao bookDao;

    @Override
    public void save() {
        System.out.println("book service save...");
        bookDao.save();
    }

    public void setBookDao(BookDao bookDao) {
        this.bookDao = bookDao;
    }
}

  3. 配置 service 与 dao 之间的关系

    <?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">

    <bean id="bookDao" class="com.bellongyan.dao.impl.BookDaoImpl"/>
    <bean id="bookService" class="com.bellongyan.service.impl.BookServiceImpl">
        <!--property标签表示配置当前bean的属性，name属性表示配置哪一个具体的属性，ref表示参照哪一个bean-->
        <property name="bookDao" ref="bookDao"/>
    </bean>

</beans>