主要有三种方式:BeanWrapper、BeanFactory和使用ApplicationContext
package com.example.demo.test;
import java.util.Date;
public class HelloWorld {
private String msg;
private Date date;
public HelloWorld() {
}
public Date getDate() {
return date;
}
public void setDate(Date date) {
this.date = date;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
}
package com.example.demo.test;
import java.util.Date;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.BeanWrapperImpl;
public class SpringTest {
public static void main(String[] args)
throws ClassNotFoundException, InstantiationException, IllegalAccessException {
Object obj = Class.forName("com.example.demo.test.HelloWorld").newInstance();
BeanWrapper bw = new BeanWrapperImpl(obj);
bw.setPropertyValue("msg", "hello world!");
bw.setPropertyValue("date", new Date());
System.out.println(bw.getPropertyValue("date") + " " + bw.getPropertyValue("msg"));
}
}
这个接口有多个实现,最常用的实现是XmlBeanFactory,示例如下
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
"<http://www.springframework.org/dtd/spring-beans.dtd>">
<beans>
<bean id="HelloWorld" class="com.example.demo.test.HelloWorld">
<property name="msg">
<value>HelloWorld</value>
</property>
<property name="date">
<ref bean="date"/>
</property>
</bean>
<bean id="date" class="java.util.Date"></bean>
</beans>
package com.example.demo.test;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.ClassPathResource;
public class SpringTest {
public static void main(String[] args) {
ClassPathResource res = new ClassPathResource("config/config.xml");
XmlBeanFactory factory = new XmlBeanFactory(res);
HelloWorld h = (HelloWorld) factory.getBean("HelloWorld");
System.out.println(h.getDate() + " " + h.getMsg());
}
}
ApplicationContext建立在BeanFactory之上,并增加了其它功能,例如对于国际化的支持、获取资源、事件传递等。示例如下,HelloWorld.java和配置都不用改,测试代码如下
package com.example.demo.test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
public class SpringTest {
public static void main(String[] args) {
ApplicationContext ac = new FileSystemXmlApplicationContext("src/config/config.xml");
HelloWorld h = (HelloWorld) ac.getBean("HelloWorld");
System.out.println(h.getDate() + " " + h.getMsg());
}
}
最常用的是ApplicationContext