Spring在项目中的应用（一）

Spring理解

很多初学者对于spring 都不太理解，或者说为什么要用，其实都不知道具体为什么，看别人都说好，为了看起来厉害一些，也用起来。

简单一句话来说：就是用spring来管理项目代码，能够让代码更简洁，层次更清晰，项目可扩展性更好，能够让别人更快的熟悉你的项目。

话不多说。就配一次看看看。

1.web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">

<!-- 定义Spring的配置的位置，可以定义多个配置文件，可以使用通配符 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:config/env/applicationContext.xml</param-value>
</context-param>

<!-- Spring MVC 配置    action映射关系-->
<servlet>
<servlet-name>springMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:config/spring/spring-action-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
<servlet-name>springMVC</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>

<!-- 加载Spring监听器 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<!--配置缓存清除监听器 处理由 JavaBean Introspector功能而引起的缓存泄露 -->
<listener>
<listener-class>
org.springframework.web.util.IntrospectorCleanupListener
</listener-class>
</listener>

<!-- request监听 -->
<listener>
<listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>

<!--配置编码过滤 -->
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>com.tom.util.filter.EncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>

<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- 验证码配置 -->
<servlet>
<servlet-name>PictureCheckCode</servlet-name>
<servlet-class>com.luoy.servlet.PictureCheckCode</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>PictureCheckCode</servlet-name>
<url-pattern>/PictureCheckCode</url-pattern>
</servlet-mapping>

<welcome-file-list>
<welcome-file>goWebIndex.html</welcome-file>
</welcome-file-list>
</web-app>

在web.xml中引入Spring 配置。把.do结尾的请求都转发到spring里面。

2.查看applicationContext.xml

<?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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd">
<!-- 数据库设置 -->
<import resource="classpath:config/spring/spring-data-config.xml" />
<!-- 服务层设置 -->
<import resource="classpath:config/spring/spring-service-config.xml" />

<import resource="classpath:config/spring/spring-bean-config.xml" />
</beans>

在这个主要的Spring文件里面，针对不同的功能再细分不同的配置文件。好处就不细说了。

3. spring-action-config.xml文件

这个文件是用来接收action的映射的。

<?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"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:ehcache="http://ehcache-spring-annotations.googlecode.com/svn/schema/ehcache-spring"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation=" http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.1.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd http://ehcache-spring-annotations.googlecode.com/svn/schema/ehcache-spring http://ehcache-spring-annotations.googlecode.com/svn/schema/ehcache-spring/ehcache-spring-4.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd  "

default-lazy-init="true">
<!-- 注册注解-->
<context:annotation-config />
<!-- 指定包下面的文件 注册注解-->
<context:component-scan base-package="com.luoy.*" />
<!-- 配置拦截器 拦截所有的请求 登录拦截-->
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/**" />
<bean class="com.luoy.interceptor.LoginInterceptor" />
</mvc:interceptor>
</mvc:interceptors>

<bean
class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="messageConverters">
<list>
<!-- String 转换器 -->
<ref bean="stringHttpMessageConverter" />
<!-- JSON 转换器 -->
<ref bean="jsonHttpMessageConverter" />
</list>
</property>
</bean>
<bean id="stringHttpMessageConverter"
class="org.springframework.http.converter.StringHttpMessageConverter" />

<bean id="jsonHttpMessageConverter"
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper">
<bean class="com.fasterxml.jackson.databind.ObjectMapper">
<property name="dateFormat">
<bean class="java.text.SimpleDateFormat">
<constructor-arg type="java.lang.String" value="yyyy-MM-dd HH:mm:ss" />
</bean>
</property>
<property name="serializationInclusion">
<value type="com.fasterxml.jackson.annotation.JsonInclude.Include">NON_NULL</value>
</property>
</bean>
</property>
</bean>

<!-- 视图处理器  对于action返回之后的页面 映射-->
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/page/" />
<property name="suffix" value=".jsp" />
</bean>

</beans>

在这个配置文件中，所有的请求都会自动映射到服务端，服务端通过注解映射。

//action 里面必须使用的注解， 对应的请求路径
@RequestMapping("ly/view/project/info")
@Controller
@Scope("prototype")
public class ProjectInfoAction {

private static final Logger log=  Logger.getLogger(ProjectInfoAction.class);

//注解引用其他的类
@Autowired
private ProjectInfoService projectInfoService;

private static final String requestPath = "ly/projectInfo/";

//表示引用Model中的数据 表示请求该类的每个Action前都会首先执行它
//这里的setReqAndRes 方法引用每次的的request和response中
@ModelAttribute
public void setReqAndRes(HttpServletRequest request, HttpServletResponse response){
this.request = request;
this.response = response;
this.session = request.getSession();
}

//表示引用Model中的数据 表示请求该类的每个Action前都会首先执行它
//model 可以自定义数据
@ModelAttribute
public void setPageParams(String page,
String rows){
if(RString.isNotBlank(page)){
this.page = Integer.valueOf(page);
}
if(RString.isNotBlank(rows)){
this.rows = Integer.valueOf(rows);
}
}

//具体的方法 也要加上注解，对应方法
@RequestMapping("goIntroduce")
public String goIntroduce(){
setAttributes();
return requestPath+"introduce";
}