Spring Framework_学习记录_12

曾经终败给现在 2022-03-01 11:56 66阅读 0赞

### 1. The Autowired Annotation ###

*  Circle.java

package org.zcs.spring;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Qualifier;
     
    
    public class Circle implements Shape { 
    
    	private Point center;
    	public Point getCenter() { 
    		return center;
    	}
    	@Autowired
    	@Qualifier("circleRelated")
    	public void setCenter(Point center) { 
    		this.center = center;
    	}
    	@Override
    	public void draw() { 
    		// TODO Auto-generated method stub
    		System.out.println("Drawing Circle:");
    		System.out.println("Circle : point is : " + center.getX() +","  + center.getY());
    		
    	}
    	
    }

*  DrwaingApp.java

package org.zcs.spring;
    
    import org.springframework.beans.factory.BeanFactory;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.AbstractApplicationContext;
    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");
     
    		Shape circle = (Shape)context.getBean("circle");
    		circle.draw();
    	}
    }

*  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:context="http://www.springframework.org/schema/context" 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 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
     			<context:annotation-config />
    
       	
       	<bean id= "pointA" class = "org.zcs.spring.Point">
    
       		 <qualifier  value = "circleRelated"></qualifier>
       		<property name="x"  value = "${pointA.pointX}"></property>
       		<property name="y"  value = "${pointA.pointY}"></property>
       	</bean>
       	<bean id= "pointB" class = "org.zcs.spring.Point">
    		<property name="x"  value = "20"></property>
    		<property name="y"  value = "0"></property>
    	</bean>
    
     	<bean id= "pointC" class = "org.zcs.spring.Point">
    		   <property name="x"  value = "0"></property>
    		   <property name="y"  value = "20"></property>
       	</bean>
     	
       	 <bean id = "circle" class= "org.zcs.spring.Circle"   >
     		 
       	</bean>
       	 	<bean class = "org.zcs.spring.MyBeanFactory" ></bean>
       	<bean class = "org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
       		<property name="locations" value = "pointsconfig.properties"></property>
       	</bean>
       	 <bean class = "org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor">
       	 </bean>
       	
      </beans>

### 2.学习记录 ###

*  本次学习了spring框架中的Required和Autowired的用法
 *  其中Autowired使用了三种方法做了演示：
    
     *  在bean中只有一个poinA时，会自动识别它
     *  在bean中有多个point时，需要将它的名字改为和Autowired的注释的方法的名字相同
 *  qualifier注释的使用。

### 3.错误记录 ###

*  在使用qualifier时出现报错，qualifer的信息总找不到。  
    \-解决办法：在beans中添加 `<context:annotation-config />`,并在头文件中添加contex的相关内容。