<?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">

    <!--注入简单类型-->
    <bean id="bookDao" class="dang.dao.impl.BookDaoImpl">
        <!--property标签：设置注入属性-->
        <!--name属性：设置注入的属性名，实际是set方法对应的名称-->
        <!--value属性：设置注入简单类型数据值-->
        <property name="connectionNum" value="100"/>
        <property name="databaseName" value="mysql"/>
    </bean>

    <bean id="userDao" class="dang.dao.impl.UserDaoImpl"/>

    <!--注入引用类型-->
    <bean id="bookService" class="dang.service.impl.BookServiceImpl">
        <!--property标签：设置注入属性-->
        <!--name属性：设置注入的属性名，实际是set方法对应的名称-->
        <!--ref属性：设置注入引用类型bean的id或name-->
        <property name="bookDao" ref="bookDao"/>
        <property name="userDao" ref="userDao"/>
    </bean>

</beans>

package dang;

import dang.service.BookService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class AppForDISet {
    public static void main( String[] args ) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
        BookService bookService = (BookService) ctx.getBean("bookService");
        bookService.save();
    }
}

package dang.service.impl;

import dang.dao.BookDao;
import dang.dao.UserDao;
import dang.service.BookService;

public class BookServiceImpl implements BookService{
    private BookDao bookDao;
    private UserDao userDao;
    //setter注入需要提供要注入对象的set方法
    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
    //setter注入需要提供要注入对象的set方法
    public void setBookDao(BookDao bookDao) {
        this.bookDao = bookDao;
    }

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

package dang.dao.impl;

import dang.dao.BookDao;

public class BookDaoImpl implements BookDao {

    private String databaseName;
    private int connectionNum;
    //setter注入需要提供要注入对象的set方法
    public void setConnectionNum(int connectionNum) {
        this.connectionNum = connectionNum;
    }
    //setter注入需要提供要注入对象的set方法
    public void setDatabaseName(String databaseName) {
        this.databaseName = databaseName;
    }

    public void save() {
        System.out.println("book dao save ..."+databaseName+","+connectionNum);
    }
}

<?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">
<!--
    标准书写
    <bean id="bookDao" class="dang.dao.impl.BookDaoImpl">
        根据构造方法参数名称注入
        <constructor-arg name="connectionNum" value="10"/>
        <constructor-arg name="databaseName" value="mysql"/>
    </bean>
    <bean id="userDao" class="dang.dao.impl.UserDaoImpl"/>

    <bean id="bookService" class="dang.service.impl.BookServiceImpl">
        <constructor-arg name="userDao" ref="userDao"/>
        <constructor-arg name="bookDao" ref="bookDao"/>
    </bean>
-->
<!--
    解决形参名称的问题，与形参名不耦合
    <bean id="bookDao" class="dang.dao.impl.BookDaoImpl">
        根据构造方法参数类型注入
        <constructor-arg type="int" value="10"/>
        <constructor-arg type="java.lang.String" value="mysql"/>
    </bean>
    <bean id="userDao" class="dang.dao.impl.UserDaoImpl"/>

    <bean id="bookService" class="dang.service.impl.BookServiceImpl">
        <constructor-arg name="userDao" ref="userDao"/>
        <constructor-arg name="bookDao" ref="bookDao"/>
    </bean>-->

    <!--解决参数类型重复问题，使用位置解决参数匹配-->
    <bean id="bookDao" class="dang.dao.impl.BookDaoImpl">
        <!--根据构造方法参数位置注入-->
        <constructor-arg index="0" value="mysql"/>
        <constructor-arg index="1" value="100"/>
    </bean>
    <bean id="userDao" class="dang.dao.impl.UserDaoImpl"/>

    <bean id="bookService" class="dang.service.impl.BookServiceImpl">
        <constructor-arg name="userDao" ref="userDao"/>
        <constructor-arg name="bookDao" ref="bookDao"/>
    </bean>
</beans>

package dang.dao.impl;

import dang.dao.BookDao;

public class BookDaoImpl implements BookDao {
    private String databaseName;
    private int connectionNum;

    public BookDaoImpl(String databaseName, int connectionNum) {
        this.databaseName = databaseName;
        this.connectionNum = connectionNum;
    }

    public void save() {
        System.out.println("book dao save ..."+databaseName+","+connectionNum);
    }
}

package dang.dao.impl;

import dang.dao.UserDao;

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

package dang.service.impl;

import dang.dao.BookDao;
import dang.dao.UserDao;
import dang.service.BookService;

public class BookServiceImpl implements BookService{
    private BookDao bookDao;
    private UserDao userDao;

    public BookServiceImpl(BookDao bookDao, UserDao userDao) {
        this.bookDao = bookDao;
        this.userDao = userDao;
    }

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

package com.itheima;

import dang.dao.BookDao;
import dang.service.BookService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class AppForDIConstructor {
    public static void main( String[] args ) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
        BookService bookService = (BookService) ctx.getBean("bookService");
        bookService.save();
    }
}