Question

我正在练习Spring基础知识，并且了解如果未指定for bean，则@Required自动将bean byName绑定。

但是，它对我不起作用。 PFB的一组类和配置文件-

主类：

public class DrawingApp {

    public static void main(String[] args) {
        AbstractApplicationContext ac = new ClassPathXmlApplicationContext("spring.xml");
        Shape shape = (Shape)ac.getBean("shape");
        shape.draw();
        ac.registerShutdownHook();
    }
}

Circle.java：

   public class Circle implements Shape {
        Point centre;

        @Override
        public void draw() {
            System.out.println("Drawing Circle");
            System.out.println("Circle centre is (" + centre.getX() + ", " + centre.getY() + ")");
        }

        public Point getCentre() {
            return centre;
        }

        @Required
        public void setCentre(Point centre) {
            this.centre = centre;
        }
}

还有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" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
            http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-3.0.xsd
            http://www.springframework.org/schema/mvc 
            http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
            http://www.springframework.org/schema/tx 
            http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

    <context:annotation-config />
    <!-- <context:component-scan base-package="/src/*"/> -->
    <bean id='triangle' class='org.mayur.spring.Triangle' autowire="byName">
        <property name="type" value="Scalene" />
        <property name="height" value="20" />
        <property name="width" value="10" />
    </bean>

    <bean id='pointA' class='org.mayur.spring.Point' name="pointD,pointE pointF">
        <property name="x" value="0" />
        <property name="y" value="0" />
    </bean>

    <bean id='pointB' class='org.mayur.spring.Point'>
        <property name="x" value="-20" />
        <property name="y" value="0" />
    </bean>

    <bean id='pointC' class='org.mayur.spring.Point'>
        <property name="x" value="0" />
        <property name="y" value="20" />
    </bean>

    <bean id='centre' class='org.mayur.spring.Point'>
        <property name="x" value="-10" />
        <property name="y" value="10" />
    </bean>

    <bean id='shape' class='org.mayur.spring.Circle'>
    </bean>
    <bean class="org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor"></bean>  

</beans>

理想情况下，此设置应将“中心” bean注入“ shape” bean中，并应打印圆形draw（）方法。

但是，我遇到了异常-

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'shape' defined in class path resource [spring.xml]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanInitializationException: Property 'centre' is required for bean 'shape'

请帮助我解决这里的问题？

@默认情况下不需要自动装配byName

0 个答案: