常见的Bean的配置有3种：
- 基于xml配置Bean
- 基于java类提供Bean定义信息
- 使用注解定义Bean
Hello类和Address类
public class Hello {
private String name;
private Address address;
public Hello() {}
public Hello(String name) {
this.name=name;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public void show(){
System.out.println("hello,"+name+","+address.getAddress()+"欢迎您！");
}
}
public class Address {
private String address;
public Address(){}
public Address(String address){
this.address=address;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
Hello hello= (Hello)ac.getBean("hello");
hello.show();
第一种：通过编写xml方式直接配置bean
<bean id="hello" class="com.bean.Hello">
<property name="name" value="老王"/>
<property name="address" ref="addr"/>
</bean>
<bean id="addr" class="com.bean.Address">
<property name="address" value="西安"/>
</bean>
举例，详细说属性值注入。
//常量注入
//常量注入
<bean id="addr" class="com.bean.Address">
<property name="address" value="西安"/>
</bean>
//Bean注入
<bean id="student" class="com.bean.Student">
<property name="name" value="剑圣"/>
<property name="addr" ref="addr"/>
//数组注入
<property name="books">
<array>
<value>花火</value>
<value>紫色</value>
<value>飞言情</value>
</array>
</property>
//List注入
<property name="hobbies">
<list>
<value>game</value>
<value>films</value>
<value>music</value>
</list>
</property>
//Map注入
<property name="cards">
<map>
<entry key="招商银行" value="123"></entry>
<entry key="农业银行" value="123"></entry>
</map>
</property>
//Set注入
<property name="games">
<set>
<value>LOL</value>
<value>王者荣耀</value>
<value>qq飞车</value>
</set>
</property>
//Null注入
<property name="wife">
<null/>
</property>
//Properties注入
<property name="info">
<props>
<prop key="学号">123</prop>
<prop key="姓名">张三</prop>
<prop key="sex">男</prop>
</props>
</property>
</bean>
//P命名空间注入
<bean id="user" class="com.bean.User" p:name="盖伦" p:age="100"/>
第二种：通过工厂模式配置bean（静态工厂和实例工厂）
1、通过静态工厂方式配置bean（静态工厂，就是将我们的对象直接放在一个静态区里面，想用的时候我们可以直接调用就行）
public class HelloStaicFactory {
private static Map<Integer, Hello> map=new HashMap<Integer, Hello>();
static{
map.put(1,new Hello("老王",new Address("北京")));
//如果这里有多个对象要传入的话，就可以根据键来检索了
}//将我们的对象都存放到工厂里面去，而且都是静态的，可以随时调用
public static Hello getHello(int id){
return map.get(id);
}//对外提供获取接口，根据id获得对象
}
通过静态工厂方法来配置bean，注意不是配置静态工厂方法实例，而是配置bean实例
<bean id="hello" class="com.test.HelloStaicFactory" factory-method="getHello">
<constructor-arg value="1"></constructor-arg>
</bean>
2、通过实例工厂方式配置bean，实例工厂与静态工厂的区别在于一个是静态的，可直接调用的，一个是需要先实例化工厂,在获取工厂里面的对象的。
public class HelloInstanceFactory {
private Map<Integer, Hello> map;
public HelloInstanceFactory(){
map=new HashMap<Integer, Hello>();
map.put(2, new Hello("老李",new Address("宝鸡")));
}
public Hello getHello(int id){
return map.get(id);
}
}
<bean id="addressFactory" class="com.bean.HelloInstanceFactory"></bean>
<bean id="hello" factory-bean="addressFactory" factory-method="getHello">
<constructor-arg value="2"></constructor-arg>
</bean>
第三种方式：通过注解方式（运用非常广泛）
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
@Component("hello")
//@component（把普通pojo实例化到spring容器中，相当于配置文件中的<bean id="hello" class="com.bean.Hello"/>）
@Scope("prototype")//原型对象，默认为单例对象,选择会执行几次构造函数。这里选择是，每次获取新对象都会执行一次构造函数，对象地址都不同。
public class Hello {
private String name="老张";
@Autowired//自动注入对象，这个注解就是spring可以自动帮你把bean里面引用的对象的bean,相当于ref的作用
private Address address;
public Hello() {
}
public Hello(String name,Address address) {
this.name=name;
this.address=address;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public void show(){
System.out.println("hello!"+name+",快来"+address.getAddress());
}
}
import org.springframework.stereotype.Component;
@Component("address")//将address对象也加载到spring容器类
public class Address {
String address="杭州";
public Address(){
}
public Address(String address){
this.address=address;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
<?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:aop="http://www.springframework.org/schema/aop"
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/aop
http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">
<context:component-scan base-package="com.bean"/>
</beans>
