Spring学习（6）---Bean定义及作用域的例子

  • Z时代
  • 2024-01-10
  • 分类：综合

本文内容纲要：Spring学习（6）---Bean定义及作用域的例子

(一)Bean的定义

先定义一个BeanAnnotation

package com.mypackage;
import org.springframework.stereotype.Component;
@Component
public class BeanAnnotation {
	public void say(String args){
		System.out.println("BeanAnnotation:"+args);
	}
}

XML配置：

<?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"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.1.xsd">
        <context:component-scan base-package="com.mypackage">
        </context:component-scan>    
</beans>

测试：

package com.mypackage;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class UnitTest {
	@Test
	public void test(){
		ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring-beansnnotation.xml");  
		BeanAnnotation bean=(BeanAnnotation)context.getBean("beanAnnotation");
		bean.say("测试");
	}
}

测试结果：

2015-7-6 11:36:44 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1342a80d: startup date [Mon Jul 06 11:36:44 CST 2015]; root of context hierarchy
2015-7-6 11:36:44 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring-beansnnotation.xml]
BeanAnnotation:测试

(二)作用域实例

指定作用域：

package com.mypackage;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
@Scope("prototype")
@Component
public class BeanAnnotation {
	public void say(String args){
		System.out.println("BeanAnnotation:"+args);
	}
	public void myhashcode(){
		System.out.println("BeanAnnotation:"+this.hashCode());
	}
}

配置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"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.1.xsd">
        <context:component-scan base-package="com.mypackage">
        </context:component-scan>    
</beans>

单元测试：

package com.mypackage;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class UnitTest {
	@Test
	public void test(){
		ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring-beansnnotation.xml");  
		BeanAnnotation bean=(BeanAnnotation)context.getBean("beanAnnotation");
		bean.myhashcode();
		BeanAnnotation bean11=(BeanAnnotation)context.getBean("beanAnnotation");
		bean11.myhashcode();
	}
}

结果：

2015-7-6 12:54:03 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1342a80d: startup date [Mon Jul 06 12:54:03 CST 2015]; root of context hierarchy
2015-7-6 12:54:03 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring-beansnnotation.xml]
BeanAnnotation:1617829356
BeanAnnotation:1567531625

bean的hashcode不一样说明是两个不同的对象。

把上述的@Scope("prototype")注解，该成@Scope，即使用默认值

得到的结果：

2015-7-6 13:00:30 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1342a80d: startup date [Mon Jul 06 13:00:30 CST 2015]; root of context hierarchy
2015-7-6 13:00:30 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring-beansnnotation.xml]
BeanAnnotation:1617829356
BeanAnnotation:1617829356

说明得到的是同一个对象。

本文内容总结：Spring学习（6）---Bean定义及作用域的例子

原文链接：https://www.cnblogs.com/JsonShare/p/4624129.html

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