Spring Framework_学习记录_05

版权声明： https://blog.csdn.net/qq_38386316/article/details/88605661

1.在bean内部注入

• DrawingApp.java

package org.zcs.spring;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
 

public class DrawingApp {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//BeanFactory factory = new  FileSystemXmlApplicationContext("src/spring.xml");
		//Triangle triangle = new Triangle();
		ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
		Triangle triangle = (Triangle)context.getBean("triangle");
		triangle.draw();
	}
}

• Triangle.java

package org.zcs.spring;

public class Triangle {
	private Point pointA;
	private Point pointB;
	private Point pointC;
	public String getTest() {
		return test;
	}
	public void setTest(String test) {
		this.test = test;
	}
	private String test;
	public Point getPointA() {
		return pointA;
	}
	public void setPointA(Point pointA) {
		this.pointA = pointA;
	}
	public Point getPointB() {
		return pointB;
	}
	public void setPointB(Point pointB) {
		this.pointB = pointB;
	}
	public Point getPointC() {
		return pointC;
	}
	public void setPointC(Point pointC) {
		this.pointC = pointC;
	}
	public void draw () {
		System.out.println("This is Point A: (" +getPointA().getX()  +"," + (getPointA().getY()) +")");
		System.out.println("This is Point B: (" +getPointB().getX()  +"," + (getPointB().getY()) +")");
		System.out.println("This is Point C: (" +getPointC().getX()  +"," + (getPointC().getY()) +")");
		 System.out.println(this.test);
		
	}
}

• spring.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"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
   
   	<bean id = "triangle" class= "org.zcs.spring.Triangle"  name = "triangle-name">
 		 <property name="pointA"  ref = "zeroPoint" >
 
 		 </property>
 		 <property name="test"   >
 			<idref bean = "zeroPoint"/>
 		 </property>
 		 <property name="pointB" >
		 		<bean id= "twoPoint" class = "org.zcs.spring.Point">
			   		<property name="x"  value = "20"></property>
			   		<property name="y"  value = "0"></property>
		   		</bean>
 		 </property>
 		 
 		 <property name="pointC"  >
 		 	   	<bean id= "threePoint" class = "org.zcs.spring.Point">
		   			<property name="x"  value = "0"></property>
		   			<property name="y"  value = "20"></property>
   				</bean>
 		 </property>
   	</bean>
   	
   	<bean id= "zeroPoint" class = "org.zcs.spring.Point">
   		<property name="x"  value = "0"></property>
   		<property name="y"  value = "0"></property>
   	</bean>
   	<alias name="triangle-name" alias="triangle-alias"/>
   	
  </beans>

2.学习笔记

• 本次学习了在Beans内部注入对象实例。
• 学习了如何定义别名。
• 认识了idref与ref的区别。

3.问题记录

• idref注入的只是目标bean的id，而不是目标bean的实例，同时使用idref容器在部署的时候还会验证这个名称是否存在。
  其实idref就跟value一样，只是将某个字符串注入到属性或者构造函数中，只不过注入的是某个bean定义的id属性值。
• 但是ref则不同，ref元素是将目标bean定义的实例注入到属性或者构造函数中，