bean的依赖注入
        【摘要】 
                    
                        
                    
                    使用构造函数 
简单类型 
public class BookDaoImpl implements BookDao {
    private int connectionNum;
    private...
    
    
    
    使用构造函数
简单类型
public class BookDaoImpl implements BookDao {
    private int connectionNum;
    private String databaseName;
    public BookDaoImpl() {
    }
    public BookDaoImpl(int connectionNum, String databaseName) {
        this.connectionNum = connectionNum;
        this.databaseName = databaseName;
    }
    @Override
    public void save() {
        System.out.println("BookDao is save..." +connectionNum + databaseName);
    }
}
  
 
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<!--    标准书写-->
    <bean id="bookDao" class="com.lihuikang.springboot_03.dao.Impl.BookDaoImpl">
        <constructor-arg name="databaseName" value="mysql"></constructor-arg>
        <constructor-arg name="connectionNum" value="8888"></constructor-arg>
    </bean>
  
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引用类型
public class BookServiceImpl implements BookService {
    private BookDao bookDao;
    public BookServiceImpl() {
    }
    public BookServiceImpl(BookDao bookDao) {
        this.bookDao = bookDao;
    }
    @Override
    public void save() {
        System.out.println("BookDaoService。。。");
        bookDao.save();
    }
}
  
 
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    <bean id="bookService" class="com.lihuikang.springboot_03.service.Impl.BookServiceImpl">
<!--        name是构造放方法中的形式参数-->
        <constructor-arg name="bookDao" ref="bookDao"></constructor-arg>
    </bean>
  
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使用set方法
简单类型
public class BookDaoImpl implements BookDao {
    private int connectionNum;
    private String databaseName;
    public int getConnectionNum() {
        return connectionNum;
    }
    public void setConnectionNum(int connectionNum) {
        this.connectionNum = connectionNum;
    }
    public String getDatabaseName() {
        return databaseName;
    }
    public void setDatabaseName(String databaseName) {
        this.databaseName = databaseName;
    }
}
  
 
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简单类型使用的是value属性
<!--    在ioc容器中添加bean-->
    <bean id="bookDao" class="com.lihuikang.springboot_02.dao.impl.BookDaoImpl" >
        <property name="databaseName" value="mysql"></property>
        <property name="connectionNum" value="10"></property>
    </bean>
  
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引用类型
public class BookServiceImpl implements BookService {
//    删除new对象
//    private BookDao bookDao = new BookDaoImpl();
    private BookDao bookDao;
// 提供set方法
    public void setBookDao(BookDao bookDao) {
        this.bookDao = bookDao;
    }
}
  
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<!--    在ioc容器中添加bean-->
    <bean id="bookDao" class="com.lihuikang.springboot_02.dao.impl.BookDaoImpl" >
        <property name="databaseName" value="mysql"></property>
        <property name="connectionNum" value="10"></property>
    </bean>
  
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    <bean id="bookService" class="com.lihuikang.springboot_02.service.impl.BookServiceImpl">
<!--        配置service和dao的关系-->
<!--        name表示配置哪一个具体的bean,ref表示参照哪一个bean-->
        <property name="bookDao" ref="bookDao"></property>
    </bean>
  
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App类
public class App {
    public static void main(String[] args) {
//        初始化容器
        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
//        获取bean
        BookDao bookDao = (BookDao) ctx.getBean("bookDao");
        bookDao.save();
        BookService bookService = (BookService) ctx.getBean("bookService");
        bookService.save();
    }
}
  
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自动装配
引用类型
<!--    在ioc容器中添加bean-->
    <bean id="bookDao" class="com.lihuikang.springboot_04.dao.impl.BookDaoImpl" >
        <property name="databaseName" value="mysql"></property>
        <property name="connectionNum" value="10"></property>
    </bean>
    <bean id="bookService" class="com.lihuikang.springboot_04.service.impl.BookServiceImpl" autowire="byType">
    </bean>
  
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文章来源: blog.csdn.net,作者:花花叔叔,版权归原作者所有,如需转载,请联系作者。
原文链接:blog.csdn.net/qq_52077949/article/details/126916486
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