bean属性

1. id、name都可以表示bean的名字

 id:以前属性中不能有特殊字符，现在放特殊字符也没关系

 name:属性可以有特殊字符

文件目录：

代码：配置文件：applicationContext.xml

Test.java

package com.neuedu.test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Test {	public static void main(String[] args) {				ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");		Object bean = ac.getBean("car");		Object bean2 = ac.getBean("car");		System.out.println(bean == bean2);	} }

Car.java

package com.neudeu.po;public class Car {	private String brand;	private double price;	public String getBrand() {		return brand;	}	public void setBrand(String brand) {		this.brand = brand;	}	public double getPrice() {		return price;	}	public void setPrice(double price) {		this.price = price;	}	@Override	public String toString() {		return "Car [brand=" + brand + ", price=" + price + "]";	}		}

输出：

<bean id="car" class="com.neudeu.po.Car"></bean> 只配置一个 car，

 Object bean = ac.getBean("car");Object bean2 = ac.getBean("car");  无论获取几次但都是同一个对象

 System.out.println(bean == bean2);故输出为 ture

2.scope属性：bean的生存范围

        1.singleton 单例（默认）

        2. proptotype (原型)每次创建新的对象

代码：配置文件：applicationContext.xml

Test.java

package com.neuedu.test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Test {	public static void main(String[] args) {				ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");		Object bean = ac.getBean("car");		Object bean2 = ac.getBean("car");		System.out.println(bean == bean2);	} }

car.java

package com.neudeu.po;public class Car {	private String brand;	private double price;		public Car() {		System.out.println("Car构造方法");	}	public String getBrand() {		return brand;	}	public void setBrand(String brand) {		this.brand = brand;	}	public double getPrice() {		return price;	}	public void setPrice(double price) {		this.price = price;	}	@Override	public String toString() {		return "Car [brand=" + brand + ", price=" + price + "]";	}		}

输出：

修改为 singleton

输出：

    

3.autowire 自动装配(可读性太差)

    1.byName    按名字装配

    2.byType 按类型装配

文件目录：

代码：配置文件：applicationContext.xml

Test.java

package com.neuedu.test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Test {	public static void main(String[] args) {				ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");			} }

idCard.java

package com.neudeu.po;public class idCard {		public idCard() {		System.out.println("IdCard...");	}	private String CardNo;		public String getCardNo() {		return CardNo;	}		public void setCardNo(String cardNo) {		CardNo = cardNo;	}}

Person.java

package com.neudeu.po;import com.neudeu.po.idCard;import java.util.List;public class Person {	private idCard idCard;		private String name;	private int age;		private List
     
       cars;		public List
      
        getCars() {		return cars;	}	public void setCars(List
       
         cars) {		this.cars = cars;	}	@Override	public String toString() {		return "Person [name=" + name + ", age=" + age + ", cars=" + cars + "]";	}	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;	}	public idCard getIdCard() {		return idCard;	}	public Person(){		System.out.println("Person...");	}	public void setIdCard(idCard idCard) {		System.out.println("setIdCard...");		this.idCard = idCard;			}		}
       
      
     

输出：

<bean id ="person" class="com.neudeu.po.Person" autowire="byType" >

autowire="byType" ：自动注入（按类型），自动的从 Spring 中找有没有  Person 里需要的 idCard 类型的对象，有点化就自动的将其注入到 Person 的属性里面去

代码：配置文件：applicationContext.xml

输出：autowire="byName" ：自动注入（按名字装配）

4. lazy-init    延迟加载

    false : 立即加载（默认）

    true : 用到时加载

代码：配置文件：applicationContext.xml

输出：与前文相比，Person 都没有执行（延迟加载）

修改代码：Test.java

package com.neuedu.test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Test {	public static void main(String[] args) {				ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");		Object bean = ac.getBean("person");  //加入代码		System.out.println(bean);   //加入代码	} }

输出：只有执行 Object bean = ac.getBean("person"); 后才会执行后续代码

5  init-method="init"    

在容器对这个bean初始化时执行该方法

代码：配置文件：applicationContext.xml

     
     		
      	
      		
       	
      		
      		
       	
      		
      
       //修改代码
      			
     

Person.java

package com.neudeu.po;import com.neudeu.po.idCard;import java.util.List;public class Person {	private idCard idCard;		private String name;	private int age;		private List
     
       cars;		public List
      
        getCars() {		return cars;	}	public void setCars(List
       
         cars) {		this.cars = cars;	}	@Override	public String toString() {		return "Person [name=" + name + ", age=" + age + ", cars=" + cars + "]";	}	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;	}	public idCard getIdCard() {		return idCard;	}	public Person(){		System.out.println("Person...");	}	public void setIdCard(idCard idCard) {		System.out.println("setIdCard...");		this.idCard = idCard;			} 	public void init() {		System.out.println("init...");  //修改代码	}		}
       
      
     

输出：bean初始化时执行 init 方法,输出 init...

6. destroy-method="destroy"：

容器关闭时执行该方法

代码：配置文件：applicationContext.xml

Person.java

package com.neudeu.po;import com.neudeu.po.idCard;import java.util.List;public class Person {	private idCard idCard;		private String name;	private int age;		private List
     
       cars;		public List
      
        getCars() {		return cars;	}	public void setCars(List
       
         cars) {		this.cars = cars;	}	@Override	public String toString() {		return "Person [name=" + name + ", age=" + age + ", cars=" + cars + "]";	}	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;	}	public idCard getIdCard() {		return idCard;	}	public Person(){		System.out.println("Person...");	}	public void setIdCard(idCard idCard) {		System.out.println("setIdCard...");		this.idCard = idCard;			} 	public void init() {		System.out.println("init...");	}	public void destroy(){		System.out.println("destroy...");  //修改代码	}		}
       
      
     

输出：并没有输出 destory...  要在关闭容器时才会执行

修改代码：Test.java

package com.neuedu.test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Test {	public static void main(String[] args) {	ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");  //修改代码		Object bean = ac.getBean("person");		System.out.println(bean);						ac.close();	} }

输出：执行关闭容器，输出 destory...