Spring温习(1)--最基础的示例

博客分类：

框架-Spring专栏

Spring XML Bean Web DAO

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-2.5.6\dist\spring.jar

spring-framework-2.5.6\lib\jakarta-commons\common-logging.jar

为了方便测试还需要：spring-framework-2.5.6\lib\junit\junit4.4.jar

第一步，先在spring资源包找到：spring-framework-2.5.6\samples\jpetstore\attributes\WEB-INF\applictionContext.xml

找到后将多余的删除，留下最基本的

Java代码

<?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>

UserDAO.java

Java代码

package com.test.domain;
public interface UserDAO {
void say();
}

UserDAOImpl.java

Java代码

package com.test.domain;
public class UserDAOImpl implements UserDAO {
@Override
public void say() {
System.out.println("i can speak");
}
}

applictionContext.xml

Xml代码

<?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>

测试类

Java代码

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();
}
}

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

Xml代码

<?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"/>
<bean id="userDAO1" class="com.test.domain.BeanFactory" factory-method="UserDAOService" />
<bean id="factory" class="com.test.domain.BeanFactory" />
<bean id="userDAO2" factory-bean="factory" factory-method="getUserDAOService" />
</beans>

BeanFactory.java

Java代码

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();
}
}

测试类

Java代码

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();
}
}

测试结果

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

Xml代码

<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:/META-INF/spring/applicationContext-*.xml</param-value>
</context-param>

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

Java代码

<?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>

那么在web.xml中应该是

Xml代码

<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath*:/META-INF/spring/applicationContext-xx.xml</param-value>
</context-param>

时间： 2024-12-26 18:55:54

Spring温习(1)--最基础的示例

Spring温习(1)--最基础的示例

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