[Spring]Spring框架搭建详解

首先是框架结构图解

Spring常用的xml标头

<?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:tx="http://www.springframework.org/schema/tx" xmlns:beans="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"> </beans>

第一步：在web.xml中配置Spring的入口DispatcherServlet

<servlet> <servlet-name>appServlet</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc-context.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>appServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping>

第二步：在springmvc-context.xml中配置注解扫描与视图解析器

<!-- 对web包中的所有类进行扫描，以完成Bean创建和自动依赖注入的功能 如果扫描到有@Component @Controller@Service等这些注解的类 则把这些类注册为bean --> <context:component-scan base-package="test.jia.com" /> <!-- 这个类用于Spring MVC视图解析 --> <beans:bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <beans:property name="prefix" value="/WEB-INF/pages/" /> <beans:property name="suffix" value=".jsp" /> </beans:bean>

到这里，Spring最基本的框架已经搭建完成了，可以写个Controller测试一下

@Controller @RequestMapping("LoginController") public class LoginController { @RequestMapping("login") public String login(HttpServletRequest request , HttpServletResponse response){ System.out.println(" welcome ! "); return "login"; } }

启动web项目后，在浏览器访问是通过的，Spring最基本的框架搭建完成。下面我们在此框架的基础上进行功能扩展。

第三步：在springmvc-context.xml中配置Spring拦截器

<!-- 拦截器配置 --> <mvc:interceptors> <mvc:interceptor> <mvc:mapping path="/*/*"/> <bean class="test.jia.com.interceptor.UrlsInterceptor"> <property name="urls"> <list> <!-- 如果请求中包含以下路径，则不进行拦截 --> <!-- 静态资源 --> <value>/js</value> <value>/css</value> <value>/image</value> <value>/images</value> <value>/png</value> <value>/jpg</value> <!-- <value>/xxx.do</value> --> </list> </property> </bean> </mvc:interceptor> </mvc:interceptors>

创建UrlsInterceptor拦截器

public class UrlsInterceptor implements HandlerInterceptor { //存放被拦截的资源路径 private String[] urls; public void setUrls(String[] urls) { this.urls = urls; } @Override public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3) throws Exception { } @Override public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3) throws Exception { } @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object object) throws Exception { //设置回传格式与编码 response.setContentType("text/html;charset=UTF-8"); //获取请求 String requestURI = request.getRequestURI(); //判断uri是否为不拦截的资源 for(String url : urls){ if(requestURI.indexOf(url)!=-1){ return true; } } //逻辑判断，是否拦截 if (1==1) { //放行 return true; }else { //拦截 return false; } } }

第四步：在springmvc-context.xml中读取property配置文件

<!-- 引入配置文件 --> <context:property-placeholder location="classpath:config.properties"/> <!-- 测试：将配置文件的username对应的值注入LoginUser的构造中 --> <beans:bean id="loginUser" class="test.jia.com.entity.LoginUser" > <constructor-arg value="${username}"></constructor-arg> </beans:bean>

注：一定要在web.xml配置Spring监听，因为Bean的注入依赖ContextLoaderListener监听

<context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springmvc-context.xml </param-value> </context-param> <!-- Spring 监听器 --> <listener> <listener-class> org.springframework.web.context.ContextLoaderListener </listener-class> </listener>

config.properties配置文件里的内容

username=username

测试：从控制层读取注入的loginUser

@RequestMapping("login") public String login(HttpServletRequest request , HttpServletResponse response){ System.out.println(" welcome ! "); WebApplicationContext context = WebApplicationContextUtils. getWebApplicationContext(request.getSession().getServletContext()); LoginUser loginUser = context.getBean("loginUser", LoginUser.class); System.out.println(loginUser); return "login"; }

第五步：在springmvc-context.xml配置：避免IE执行AJAX时,返回JSON出现下载文件

<!-- 避免IE执行AJAX时,返回JSON出现下载文件 --> <!-- ①错误： Not found org.springframework.http.converter.json.MappingJacksonHttpMessageConverter 解决方案： Spring版本变化导致，将class里的 MappingJacksonHttpMessageConverter改为MappingJackson2HttpMessageConverter ②错误： NoClassDefFoundError: com/fasterxml/jackson/core/JsonProcessingException 解决方案：需要jackson相关Jar包支持 Jar依赖： jackson-core-2.6.0-rc4.jar jackson-databind-2.6.0-rc4.jar jackson-annotations-2.6.0-rc4.jar --> <bean id="mappingJacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"> <property name="supportedMediaTypes"> <list> <value>text/html;charset=UTF-8</value> </list> </property> </bean>

第六步：在springmvc-context.xml配置Spring的文件上传相关内容

<!-- 配置springmvc的上传功能 id必须是multipartResolver --> <!-- 错误： NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory 解决方案： Spring的CommonsMultipartResolver需要apache的FileItemFactory支持 Jar依赖： commons-fileupload.jar commons-io.jar --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- maxUploadSize:文件上传的最大值以byte为单位 --> <property name="maxUploadSize" value="102400000"></property> <!-- 设置默认编码 --> <property name="defaultEncoding" value="utf-8" /> </bean>

第七步：在web.xml配置字符编码过滤器

<!-- 字符编码过滤器 --> <filter> <filter-name>encodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <!-- 注入默认属性 --> <init-param> <description>字符集编码</description> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> </filter> <filter-mapping> <!-- 过滤器名称 --> <filter-name>encodingFilter</filter-name> <!-- 拦截哪些请求 --> <url-pattern>/*</url-pattern> </filter-mapping>