SpringMVC基于代码的配置方式（零配置，无web.xml）

基于配置文件的web项目维护起来可能会更方便，但是有时候我们会有一些特殊的需求，比如防止客户胡乱更改配置，这时候我们需要给配置隐藏到代码中。

1.创建一个动态web项目（无需web.xml）

2.右键项目添加几个package: com.easyweb.config (保存项目配置) com.easyweb.controller （保存springMvc controller）

3.在 com.easyweb.config 新建一个类 WebApplicationStartup ，这个类实现WebApplicationInitializer 接口，是项目的入口，作用类似于web.xml，具体代码如下：

package com.easyweb.config;import javax.servlet.MultipartConfigElement;import javax.servlet.ServletContext;import javax.servlet.ServletException;import javax.servlet.ServletRegistration.Dynamic;import org.springframework.web.WebApplicationInitializer;import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;import org.springframework.web.servlet.DispatcherServlet;/** * 服务器启动入口类 *  * @author Administrator * */public class WebApplicationStartup implements WebApplicationInitializer {  private static final String SERVLET_NAME = "Spring-mvc";  private static final long MAX_FILE_UPLOAD_SIZE = 1024 * 1024 * 5; // 5 Mb  private static final int FILE_SIZE_THRESHOLD = 1024 * 1024; // After 1Mb  private static final long MAX_REQUEST_SIZE = -1L; // No request size limit  /**   * 服务器启动调用此方法，在这里可以做配置 作用与web.xml相同   */  @Override  public void onStartup(ServletContext servletContext) throws ServletException {    // 注册springMvc的servlet    this.addServlet(servletContext);    // 注册过滤器    // servletContext.addFilter(arg0, arg1)    // 注册监听器    // servletContext.addListener(arg0);  }  /**   * 注册Spring servlet   *    * @param servletContext   */  private void addServlet(ServletContext servletContext) {    // 构建一个application context    AnnotationConfigWebApplicationContext webContext = createWebContext(SpringMVC.class, ViewConfiguration.class);    // 注册spring mvc 的 servlet    Dynamic dynamic = servletContext.addServlet(SERVLET_NAME, new DispatcherServlet(webContext));    // 添加springMVC 允许访问的Controller后缀    dynamic.addMapping("*.html", "*.ajax", "*.css", "*.js", "*.gif", "*.jpg", "*.png");    // 全部通过请用 “/”    // dynamic.addMapping("/");    dynamic.setLoadOnStartup(1);    dynamic.setMultipartConfig(new MultipartConfigElement(null, MAX_FILE_UPLOAD_SIZE, MAX_REQUEST_SIZE, FILE_SIZE_THRESHOLD));  }  /**   * 通过自定义的配置类来实例化一个Web Application Context   *    * @param annotatedClasses   * @return   */  private AnnotationConfigWebApplicationContext createWebContext(Class<?>... annotatedClasses) {    AnnotationConfigWebApplicationContext webContext = new AnnotationConfigWebApplicationContext();    webContext.register(annotatedClasses);    return webContext;  }}
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4.在com.easyweb.config 下添加类 SpringMVC 继承 WebMvcConfigurerAdapter，这个类的作用是进行SpringMVC的一些配置，代码如下：

package com.easyweb.config;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;@Configuration@EnableWebMvc//指明controller所在的包名@ComponentScan(basePackages = {"com.easyweb.controller"})public class SpringMVC extends WebMvcConfigurerAdapter {  /**   * 非必须   */  @Override  public void configureDefaultServletHandling(final DefaultServletHandlerConfigurer configurer) {    configurer.enable();  }  /**   * 如果项目的一些资源文件放在/WEB-INF/resources/下面   * 在浏览器访问的地址就是类似：http://host:port/projectName/WEB-INF/resources/xxx.css   * 但是加了如下定义之后就可以这样访问：   * http://host:port/projectName/resources/xxx.css   * 非必须   */  @Override  public void addResourceHandlers(final ResourceHandlerRegistry registry) {    registry.addResourceHandler("/resources/**/*").addResourceLocations("/WEB-INF/resources/");  }}
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5.添加view配置文件com.easyweb.config下新建类ViewConfiguration，里面可以根据自己的需要定义视图拦截器：

package com.easyweb.config;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.ViewResolver;import org.springframework.web.servlet.view.JstlView;import org.springframework.web.servlet.view.UrlBasedViewResolver;import org.springframework.web.servlet.view.tiles2.TilesConfigurer;import org.springframework.web.servlet.view.tiles2.TilesView;@Configurationpublic class ViewConfiguration {    @Bean    public ViewResolver urlBasedViewResolver() {        UrlBasedViewResolver viewResolver;        viewResolver = new UrlBasedViewResolver();        viewResolver.setOrder(2);        viewResolver.setPrefix("/WEB-INF/");        viewResolver.setSuffix(".jsp");        viewResolver.setViewClass(JstlView.class);        // for debug envirment        viewResolver.setCache(false);        return viewResolver;    }    @Bean    public ViewResolver tilesViewResolver() {        UrlBasedViewResolver urlBasedViewResolver = new UrlBasedViewResolver();        urlBasedViewResolver.setOrder(1);        urlBasedViewResolver.setViewClass(TilesView.class);        //urlBasedViewResolver.        return urlBasedViewResolver;    }    @Bean    public TilesConfigurer tilesConfigurer() {        TilesConfigurer tilesConfigurer = new TilesConfigurer();        tilesConfigurer.setDefinitions(new String[] { "classpath:tiles.xml" });        return tilesConfigurer;    }}
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6.本例中还用了tiles视图解析器，替换了原始的include方式

7.完整代码已上传 
http://download.csdn.net/detail/u013816347/8998891

学习路上，欢迎评论指正。