spring

时间：2010-07-18 来源：sfwhhp

简单spring实例
第一步：下载spring.jar，commons-logging.jar包。并导入工程
导入步骤：右击工程--》Build Path--》Add External Archiyes...

第二步：工程中新建三个java文件

文件一：

package com.springination.chapter01.hello;

public interface IGreetingService {
        public void sayGreeting();

}

文件二：

package com.springination.chapter01.hello;

public class GreetingServiceImpl implements IGreetingService {

        private String greeting;
        public GreetingServiceImpl(){}
        public GreetingServiceImpl(String greeting){
                this.greeting = greeting;
        }
        public void sayGreeting(){
                System.out.println(greeting);
        }
        public void setGreeting(String greeting) {
                this.greeting = greeting;
        }

}

文件三：

package com.springination.chapter01.hello;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.Resource;

public class Helloworld {

        /**
         * @param args
         */
        public static void main(String[] args) 
        {
                //方法一  FileSystemResource类，默认xml文件的路径在工程目录下
                Resource resource =  new FileSystemResource("hello.xml");
                BeanFactory factory = new XmlBeanFactory(resource);
                GreetingServiceImpl greetingService = (GreetingServiceImpl) factory.getBean("greetingService");
                greetingService.sayGreeting();
                
                //方法二 ClassPathXmlApplicationContext类，默认的寻找xml文件的路径就在src目录下
//              ApplicationContext ac = new ClassPathXmlApplicationContext("hello.xml");
//              GreetingServiceImpl greetingService = (GreetingServiceImpl) ac.getBean("greetingService");
//              greetingService.sayGreeting();
                
                //方法三 FileSystemXmlApplicationContext类，默认的寻找xml文件的路径就在src目录下
//              ApplicationContext ac = new FileSystemXmlApplicationContext("hello.xml");
//              GreetingServiceImpl greetingService = (GreetingServiceImpl) ac.getBean("greetingService");
//              greetingService.sayGreeting();
        }

}

第三步：新建hello.xml文件

<?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="greetingService"
                class="com.springination.chapter01.hello.GreetingServiceImpl">
                <property name="greeting">
                        <value>hello world</value>
                </property>
        </bean>   
</beans>

hello.xml文件的具体存放位置，要看在第二步中helloworld.java文件用到的获取xml问价你的类。上面列举了三种。都有存放位置的注释。

遇到的问题一：

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory

原因，没导入commons-logging.jar包

问题二：

Caused by: java.io.FileNotFoundException: hello.xml (系统找不到指定的文件。)

hello.xml文件的存放位置不正确：具体见第二步中文件三里的注释。