Spring基于XML配置方式注入bean对象和@Resource注解的使用
基于SpringBoot框架企业级应用系统开发全面实战(01.08_xml文件配置测试_recv.mp4)->{Demo1-11}
1、主题:
使用注解进行bean定义和依赖的内容；
第一步:
传统如何配置Bean并且完成Bean直接的依赖关系的建立。
建立三个类，Office ,Car,Boss 需要在Spring容器中配置为Bean；
Spring的IOC容器注入bean对象
一、基于XML配置bean方式
创建三个Java实体类用于测试
com.test.springoffice
Java实体类的set方法是SpringIOC注入，在使用XML配置bean时所必需。
Boss
package com.test.sprintoffice;
public class Boss {
private Car car;
private Office office;
public Car getCar() {
return car;
}
public void setCar(Car car) {
this.car = car;
}
public Office getOffice() {
return office;
}
public void setOffice(Office office) {
this.office = office;
}
public String toString(){
return "car:"+car+"\n"+"office:"+office;
}
}
Car
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;
}
public String toString(){
return "brand:"+brand+","+"price"+price;
}
}Office
package com.test.sprintoffice;
public class Office {
private String officeNo="001";
public String getOfficeNo() {
return officeNo;
}
public void setOfficeNo(String officeNo) {
this.officeNo = officeNo;
}
public String toString(){
return "officeNo:"+officeNo;
}
}
bean.xml( applicationContext.xml )
元素 bean
标签 property
属性 name ref/value
测试类 AnnoToCTest
/**
* 以传统方式完成bean注入；
* @author Administrator
*
*/
public class AnnoToCTest {
public static void main(String[] args) {
//读取配置文件；
ApplicationContext ctx=new ClassPathXmlApplicationContext("bean.xml");
Boss boss=(Boss) ctx.getBean("boss");
System.out.println(boss+"\t");
/* System.out.println(boss.getCar()+"\t");
System.out.println(boss.getOffice()+"\t");*/
}
}
二、基于@Autowired注解配置bean
bean2.xml
基于@Autowired注解自动注入IOC，不再强制需要该实体类的set方法（情况一、情况三）
boss
一、标注在成员变量上
/**
* 使用@Autowired注释Boss
* @author Administrator
*
*/
public class Boss {
//移除setter方法；
/*@Autowired
private Car car;
@Autowired
private Office office;
public String toString(){
return "car:"+car+"\n"+"office:"+office;
}
}
二、注释标注在setter上
//注释标注在setter上
private Car car;
private Office office;
@Autowired
public void setCar(Car car) {
this.car = car;
}
@Autowired
public void setOffice(@Qualifier("office2")Office office) {
this.office = office;
}
public String toString(){
return "car:"+car+"\n"+"office:"+office;
}三、标注在构造函数上
//标注在构造函数上
private Car car;
private Office office;
@Autowired(required=false)
public Boss(Car car, @Qualifier("office2")Office office) {
this.car = car;
this.office = office;
}
public String toString(){
return "car:"+car+"\n"+"office:"+office;
}当候选Bean数目不为1时应对方法
问题:
当候选Bean数目不为1时应对方法；
@Autowired
BeanCreationException
不强制必须存在匹配的一个bean
//标注在构造函数上
private Car car;
private Office office;
@Autowired(required=false)
public Boss(Car car, @Qualifier("office2")Office office) {
this.car = car;
this.office = office;
}
public String toString(){
return "car:"+car+"\n"+"office:"+office;
}@Autowired(required=false) 这种写法，不能应用于：二、注释标注在setter上
当配置相同类型多个id值的bean
/**
* 使用@Autowired注释Boss
* @author Administrator
*
*/
public class Boss {
//移除setter方法；
/*@Autowired(required=false)
private Car car;
@Autowired(required=false)
@Qualifier("office")
private Office office;
public String toString(){
return "car:"+car+"\n"+"office:"+office;
}*/
//注释标注在setter上；
/*private Car car;
private Office office;
@Autowired
public void setCar(Car car) {
this.car = car;
}
@Autowired
public void setOffice(@Qualifier("office2")Office office) {
this.office = office;
}
public String toString(){
return "car:"+car+"\n"+"office:"+office;
}*/
//标注在构造函数上
private Car car;
private Office office;
@Autowired(required=false)
public Boss(Car car, @Qualifier("office2")Office office) {
this.car = car;
this.office = office;
}
public String toString(){
return "car:"+car+"\n"+"office:"+office;
}
}主题:
JSR-250注释；
@Resource(byName) name=Bean type=Bean的类型 ==@Autowired(byType)生命周期；接口:initializingBean/DisposableBean bean元素指定:init-method/destory/method
@PostConstruct 类实例化之后调用；
@PreDestroy 类销毁之前调用；
@Component 组件层
@Service 业务层
@Controller 控制层
@Resource(byName)的注解
bean2.xml
Boos
/**
* 使用@Resource注释Boss
* @author Administrator
*
*/
public class Boss {
//移除setter方法；
@Resource
private Car car;
@Resource(name="office")
private Office office;
@PostConstruct
public void postConstruct1(){
System.out.println("postConstruct1");
}
@PreDestroy
public void preDestory1(){
System.out.println("preDestory1");
}
public String toString(){
return "car:"+car+"\n"+"office:"+office;
}
}测试类 AnnoToCTest
/**
* 以传统方式完成bean注入；
* @author Administrator
*
*/
public class AnnoToCTest {
public static void main(String[] args) {
//读取配置文件；
ClassPathXmlApplicationContext ctx=new ClassPathXmlApplicationContext("bean2.xml");
Boss boss=(Boss) ctx.getBean("boss");
System.out.println(boss+"\t");
ctx.destroy();//关闭spring容器，来触发Bean销毁方法的执行；
/* System.out.println(boss.getCar()+"\t");
System.out.println(boss.getOffice()+"\t");*/
}
}
使用注解@Component配置注入bean
@Repository、@Service、@Controller == @Component
位置要放在类的定义 public class XXX 的定义行之上
bean.xml
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参考资料：@Autowired @Resource @Qualifier的区别
end