前言

setter注入

引用类型

通过一个案例回顾setter注入引用类型·

Step1:添加User

在原先Blog的基础上添加。
整体目录结构如下图所示

UserDaoImpl.java

public class UserDaoImpl implements UserDao {
    public void save() {
        System.out.println("user dao save ...");
    }
}
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Step2:修改BookServiceImpl

BookServiceImpl.java

public class BookServiceImpl implements BookService {

    private  BookDao bookDao;
    private UserDao userDao;
    public void save(){
        System.out.println("book service save .....");
        bookDao.save();
        userDao.save();
    }
    //提供对应的set方法
    public void setBookDao(BookDao bookDao){
        this.bookDao=bookDao;
    }
    public void setUserDao(UserDao userDao){
        this.userDao=userDao;
    }
}

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Step3:修改配置

applicationContext.xml

<?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">
<!--    配置bean-->
    <bean id="userDao" class="com.itheima.dao.Impl.UserDaoImpl"/>
    <bean id="bookDao" class="com.itheima.dao.Impl.BookDaoImpl"/>
    <bean id="bookService" class="com.itheima.service.Impl.BookServiceImpl">
<!--        配置server与dao的关系-->
<!--        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属性表示参照哪一个bean-->
        <property name="bookDao" ref="bookDao"/>
        <property name="userDao" ref="userDao"/>
    </bean>
</beans>
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Step4:run APP2.java

public class APP2 {
    public static void main(String[] args) {
        //获取IoC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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简单类型

.

Step1:定义BookDaoImpl.java

BookDaoImpl.java

public class BookDaoImpl implements BookDao {
    private  int connectionNum;
    private String databaseName;
    public void save(){
        System.out.println("book dao save ....."+databaseName+'.'+connectionNum);
    }
    //提供对应的set方法
    public void setconnectionNum(int connectionNum){
        this.connectionNum=connectionNum;
    }
    public void setdatabaseName(String databaseName){
        this.databaseName=databaseName;
    }
}
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Step2:修改配置

applicationContext.xml

<?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">
<!--    配置bean-->
    <bean id="bookDao" class="com.itheima.dao.Impl.BookDaoImpl">
        <property name="connectionNum" value="10"/>
        <property name="databaseName" value="mysql"/>
    </bean>

</beans>
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Step3:run 一下

APP2.java

public class APP2 {
    public static void main(String[] args) {
        //获取IoC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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构造器注入

引用类型

简单类型

小Demo

BookDaoImpl.java

public class BookDaoImpl implements BookDao {
    private  int connectionNum;
    private String databaseName;
    public BookDaoImpl(int connectionNum,String databaseName){
        this.connectionNum=connectionNum;
        this.databaseName=databaseName;
    }
    public void save(){
        System.out.println("book dao save ....."+databaseName+'.'+connectionNum);
    }
}
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applicationContext.xml

<?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.itheima.dao.Impl.BookDaoImpl">
        <constructor-arg name="connectionNum" value="10"/>
        <constructor-arg name="databaseName" value="mysql"/>
    </bean>

</beans>
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参数适配

依赖自动装配