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,可是有时候我们会有一些特殊的需求,比方防止客户胡乱更改配置,这时候我们须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.右键项目加入几个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,作用相似于web.xml,详细代码例如以下:
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;
/**
* server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
/**
* server启动调用此方法,在这里能够做配置 作用与web.xml同样
*/
@Override
public void onStartup(ServletContext servletContext) throws ServletException {
// 注冊springMvc的servlet
this.addServlet(servletContext);
// 注冊过滤器
// servletContext.addFilter(arg0, arg1)
// 注冊监听器
// servletContext.addListener(arg0);
}
/**
* 注冊Spring servlet
*
* @param servletContext
*/
private void addServlet(ServletContext servletContext) {
// 构建一个application context
AnnotationConfigWebApplicationContext webContext = createWebContext(SpringMVC.class, ViewConfiguration.class);
// 注冊spring mvc 的 servlet
Dynamic dynamic = servletContext.addServlet(SERVLET_NAME, new DispatcherServlet(webContext));
// 加入springMVC 同意訪问的Controller后缀
dynamic.addMapping("*.html", "*.ajax", "*.css", "*.js", "*.gif", "*.jpg", "*.png");
// 所有通过请用 “/”
// dynamic.addMapping("/");
dynamic.setLoadOnStartup(1);
dynamic.setMultipartConfig(new MultipartConfigElement(null, MAX_FILE_UPLOAD_SIZE, MAX_REQUEST_SIZE, FILE_SIZE_THRESHOLD));
}
/**
* 通过自己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;
}
}
4.在com.easyweb.config 下加入类 SpringMVC 继承 WebMvcConfigurerAdapter。这个类的作用是进行SpringMVC的一些配置,代码例如以下:
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();
}
/**
* 假设项目的一些资源文件放在/WEB-INF/resources/以下
* 在浏览器訪问的地址就是相似:http://host:port/projectName/WEB-INF/resources/xxx.css
* 可是加了例如以下定义之后就能够这样訪问:
* http://host:port/projectName/resources/xxx.css
* 非必须
*/
@Override
public void addResourceHandlers(final ResourceHandlerRegistry registry) {
registry.addResourceHandler("/resources/**/*").addResourceLocations("/WEB-INF/resources/");
}
}
5.加入view配置文件com.easyweb.config下新建类ViewConfiguration,里面能够依据自己的须要定义视图拦截器:
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;
@Configuration
public 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;
}
}
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。