spring教程笔记4

最新推荐文章于 2025-01-12 20:51:11 发布

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本文探讨了Spring框架中通过构造函数注入属性值的方法及自动装配bean属性的三种方式：byName, byType和constructor。展示了如何在XML配置文件中定义bean并自动装配其依赖。

通过构造函数注入属性值

package com.hsp.constructor;

public class Employee {

	private String name;
	private int age;
	
	public Employee(){
		
	}
	
	public Employee(String name, int age) {
		
		System.out.println("Employee(String name, int age) 函数被调用..");
		this.name = name;
		this.age = age;
	}
	
	public Employee(String name){
		this.name=name;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
}

<?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:tx="http://www.springframework.org/schema/tx"
		xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
				http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

<!-- 配置一个雇员对象 -->
<bean id="employee" class="com.hsp.constructor.Employee">
<!-- 通过构造函数来注入属性值 -->	
<constructor-arg index="0" type="java.lang.String" value="大明风华" />
<constructor-arg index="1" type="int" value="22"/>
</bean>
</beans>

package com.hsp.constructor;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class App1 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		ApplicationContext ac=new ClassPathXmlApplicationContext("com/hsp/constructor/beans.xml");
	
		Employee ee=(Employee) ac.getBean("employee");
		System.out.println(ee.getName());
	
	}

}

运行结果
2020-3-2 12:30:52 org.springframework.context.support.AbstractApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d: display name [org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d]; startup date [Mon Mar 02 12:30:52 CST 2020]; root of context hierarchy
2020-3-2 12:30:52 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [com/hsp/constructor/beans.xml]
2020-3-2 12:30:52 org.springframework.context.support.AbstractApplicationContext obtainFreshBeanFactory
信息: Bean factory for application context [org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d]: org.springframework.beans.factory.support.DefaultListableBeanFactory@290fbc
2020-3-2 12:30:52 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@290fbc: defining beans [employee]; root of factory hierarchy
Employee(String name, int age) 函数被调用…
大明风华

自动装配bean的属性值

①byName

package com.hsp.autowire;



public class Dog {

	private String name;
	private int age;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
}

package com.hsp.autowire;

public class Master {

	private String name;
	private Dog dog;
	
	
	
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Dog getDog() {
		return dog;
	}
	public void setDog(Dog dog) {
		this.dog = dog;
	}
}

<?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:tx="http://www.springframework.org/schema/tx"
		xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
				http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd" 
				>

<!-- 配置一个master对象 -->
<bean id="master" class="com.hsp.autowire.Master" autowire="byName">
<property name="name">
<value>二哈的主人</value>
</property>
</bean>
<!-- 配置dog对象 -->
<bean id="dog"  class="com.hsp.autowire.Dog">
<property name="name" value="大黄"/>
<property name="age" value="3"/>
</bean>
</beans>

package com.hsp.autowire;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class App1 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		ApplicationContext ac=new ClassPathXmlApplicationContext("com/hsp/autowire/beans.xml");
		//获取
		Master master=(Master) ac.getBean("master");
		System.out.println(master.getName()+" 养了条"+master.getDog().getName());
	}

}

运行结果：
2020-3-2 14:35:51 org.springframework.context.support.AbstractApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d: display name [org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d]; startup date [Mon Mar 02 14:35:51 CST 2020]; root of context hierarchy
2020-3-2 14:35:51 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [com/hsp/autowire/beans.xml]
2020-3-2 14:35:52 org.springframework.context.support.AbstractApplicationContext obtainFreshBeanFactory
信息: Bean factory for application context [org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d]: org.springframework.beans.factory.support.DefaultListableBeanFactory@1b8d6f7
2020-3-2 14:35:52 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@1b8d6f7: defining beans [master,dog]; root of factory hierarchy
二哈的主人养了条大黄

②byType

<?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:tx="http://www.springframework.org/schema/tx"
		xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
				http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd" 
				>

<!-- 配置一个master对象 -->
<bean id="master" class="com.hsp.autowire.Master" autowire="byType">
<property name="name">
<value>二哈的主人</value>
</property>
</bean>
<!-- 配置dog对象 -->
<bean id="dog11"  class="com.hsp.autowire.Dog">
<property name="name" value="大黄"/>
<property name="age" value="3"/>
</bean>
</beans>

运行结果
2020-3-2 12:45:33 org.springframework.context.support.AbstractApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d: display name [org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d]; startup date [Mon Mar 02 12:45:33 CST 2020]; root of context hierarchy
2020-3-2 12:45:33 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [com/hsp/autowire/beans.xml]
2020-3-2 12:45:34 org.springframework.context.support.AbstractApplicationContext obtainFreshBeanFactory
信息: Bean factory for application context [org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d]: org.springframework.beans.factory.support.DefaultListableBeanFactory@1b8d6f7
2020-3-2 12:45:34 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@1b8d6f7: defining beans [master,dog11]; root of factory hierarchy
二哈的主人养了条大黄

③`<bean id="master" class="com.hsp.autowire.Master" autowire="constructor">`

package com.hsp.autowire;

public class Master {

	private String name;
	private Dog dog;
	
	
	public Master(Dog dog){
		this.dog=dog;
	}
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Dog getDog() {
		return dog;
	}
	public void setDog(Dog dog) {
		this.dog = dog;
	}
}

<?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:tx="http://www.springframework.org/schema/tx"
		xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
				http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd" 
				>
<!-- 配置一个master对象 -->
<bean id="master" class="com.hsp.autowire.Master" autowire="constructor">
<property name="name">
<value>二哈的主人</value>
</property>
</bean>
<!-- 配置dog对象 -->
<bean id="dog11"  class="com.hsp.autowire.Dog">
<property name="name" value="大黄"/>
<property name="age" value="3"/>
</bean>
</beans>

运行结果：
2020-3-2 12:47:49 org.springframework.context.support.AbstractApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d: display name [org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d]; startup date [Mon Mar 02 12:47:49 CST 2020]; root of context hierarchy
2020-3-2 12:47:49 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [com/hsp/autowire/beans.xml]
2020-3-2 12:47:50 org.springframework.context.support.AbstractApplicationContext obtainFreshBeanFactory
信息: Bean factory for application context [org.springframework.context.support.ClassPathXmlApplicationContext@1ef9f1d]: org.springframework.beans.factory.support.DefaultListableBeanFactory@1b8d6f7
2020-3-2 12:47:50 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@1b8d6f7: defining beans [master,dog11]; root of factory hierarchy
二哈的主人养了条大黄

④
⑤