Spring温习(1)--最基础的示例

Spring温习(1)--最基础的示例

博客分类： 

• 框架-Spring专栏

SpringXMLBeanWebDAO

从现在开始，我将从Spring为起点，逐步复习几大框架各方面的知识，以便今后查看使用

第一各Spring示例

必须包:spring-framework-2.5.6distspring.jar

         spring-framework-2.5.6libjakarta-commonscommon-logging.jar

为了方便测试还需要：spring-framework-2.5.6libjunitjunit4.4.jar

第一步，先在spring资源包找到：spring-framework-2.5.6samplesjpetstoreattributesWEB-INFapplictionContext.xml

找到后将多余的删除，留下最基本的

<span style="font-size: medium;"><span style="font-size: large;"><?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:tx="http://www.springframework.org/schema/tx"
    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/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

</beans></span></span>

 UserDAO.java

<span style="font-size: medium;"><span style="font-size: large;">package com.test.domain;

public interface UserDAO {
  void say();
}</span></span><span style="font-size: large;">
</span>

 UserDAOImpl.java

<span style="font-size: medium;"><span style="font-size: large;">package com.test.domain;

public class UserDAOImpl implements UserDAO {

    @Override
    public void say() {
      System.out.println("i can speak");
    }

}</span></span><span style="font-size: large;">
</span>

applictionContext.xml

<span style="font-size: medium;"><span style="font-size: large;"><?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "http://www.springframework.org/dtd/spring-beans-2.0.dtd">

<beans>
<bean  id="userDAO" class="com.test.domain.UserDAOImpl"/>
</beans></span></span><span style="font-size: large;">
</span>

 测试类

<span style="font-size: medium;"><span style="font-size: large;">package com.test.domain;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

public class MyTest {

    @Test
    public void testUser(){
             ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
             UserDAO dao=(UserDAO)context.getBean("userDAO");
             dao.say();
    }

}</span></span><span style="font-size: large;">
</span>

 测试结果：i can speak

Spring加载XML配置文件的方式

 spring 中加载xml配置文件的方式,好像有3种, xml是最常见的spring 应用系统配置源。Spring中的几种容器都支持使用xml装配bean，包括：     XmlBeanFactory ，     ClassPathXmlApplicationContext ，     FileSystemXmlApplicationContext ，     XmlWebApplicationContext

一、XmlBeanFactory 引用资源     Resource resource = new ClassPathResource("appcontext.xml");     BeanFactory factory = new XmlBeanFactory(resource); 二、ClassPathXmlApplicationContext  编译路径     1)ApplicationContext factory=new ClassPathXmlApplicationContext("classpath:appcontext.xml");     2)ApplicationContext factory=new ClassPathXmlApplicationContext("appcontext.xml");   // src目录下的     3)ApplicationContext factory=new ClassPathXmlApplicationContext("conf/appcontext.xml");   // src/conf 目录下的     4)ApplicationContext factory=new ClassPathXmlApplicationContext("file:G:/Test/src/appcontext.xml");

     5)String[] locations = {"bean1.xml", "bean2.xml", "bean3.xml"};       ApplicationContext ctx = new ClassPathXmlApplication(locations);

三 、 用文件系统的路径    1) ApplicationContext factory=new FileSystemXmlApplicationContext("src/appcontext.xml");     //使用了  classpath:  前缀,作为标志,  这样,FileSystemXmlApplicationContext 也能够读入classpath下的相对路径     2)ApplicationContext factory=new FileSystemXmlApplicationContext("classpath:appcontext.xml");     3)ApplicationContext factory=new FileSystemXmlApplicationContext("file:G:/Test/src/appcontext.xml");     4)ApplicationContext factory=new FileSystemXmlApplicationContext("G:/Test/src/appcontext.xml");

    5)String[] locations = {"bean1.xml", "bean2.xml", "bean3.xml"};         ApplicationContext ctx = new FileSystemXmlApplicationContext(locations );

四、XmlWebApplicationContext   是专为Web工程定制的。     ServletContext servletContext = request.getSession().getServletContext();     ApplicationContext ctx = WebApplicationContextUtils.getWebApplicationContext(servletContext );

注：其中FileSystemXmlApplicationContext和ClassPathXmlApplicationContext与BeanFactory的xml文件定位方式一样是基于路径的

Spring的实例化Bean有三种方式：

 使用类构造器直接实例化

 使用静态工厂的方法实例化

 使用实例工厂方法实例化

具体对应配置如

<span style="font-size: medium;"><span style="font-size: large;"><?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "http://www.springframework.org/dtd/spring-beans-2.0.dtd">

<beans>
<!--Spring的实例化Bean有三种方式：-->
        <!-- 使用类构造器直接实例化 -->
        <bean  id="userDAO" class="com.test.domain.UserDAOImpl"/>
        <!-- 使用静态工厂的方法实例化 -->
        <bean id="userDAO1" class="com.test.domain.BeanFactory" factory-method="UserDAOService" />
        <!-- 使用实例工厂方法实例化 -->
        <bean id="factory" class="com.test.domain.BeanFactory" />
        <bean id="userDAO2" factory-bean="factory" factory-method="getUserDAOService" />
</beans>
</span></span>

 BeanFactory.java

<span style="font-size: medium;"><span style="font-size: large;">package com.test.domain;

public class BeanFactory {

        //使用静态工厂的方法实例化使用
        public static UserDAO UserDAOService()
        {
            return new UserDAOImpl();
        }

        public UserDAO getUserDAOService()
        {
            return new UserDAOImpl();
        }

}</span></span><span style="font-size: medium;"><span style="font-size: large;">
</span></span>

 测试类

<span style="font-size: medium;"><span style="font-size: large;">package com.test.domain;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

public class MyTest {

    @Test
    public void testUser(){
             ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
             UserDAO dao=(UserDAO)context.getBean("userDAO");
             dao.say();
             UserDAO dao2=(UserDAO)context.getBean("userDAO2");
             dao2.say();
             UserDAO dao3=(UserDAO)context.getBean("userDAO3");
             dao3.say();
    }

}
</span></span>

测试结果

i can speak

i can speak

i can speak

PS：Spring的配置文件引入方式

1)传统配置多个文件,applicationContext-xx.xml,applicationContext-yy.xml,applicatonContext-zz.xml

   那么在web.xml中引入这么多文件可以是这样写

<span style="font-size: large;"> <context-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>classpath:/META-INF/spring/applicationContext-*.xml</param-value>
 </context-param></span>

 2)第二种方式，也是上面那么三个配置文件，那么我们可以将-yy.xml和-zz.xml都配置在-xx.xml中去，然后再在web.xml中单独配置-xx.xml就可以

     applicationContext-xx.xml

<span style="font-size: large;"><?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:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <import resource="classpath:/META-INF/spring/applicationContext-yy.xml" />

    <import resource="classpath:/META-INF/spring/applicationContext-zz.xml" />

</beans></span>

 那么在web.xml中应该是

<span style="font-size: large;"><context-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>classpath*:/META-INF/spring/applicationContext-xx.xml</param-value>
 </context-param></span>