零配置文件搭建SpringMvc
SpringMvc 流程原理
（1）用户发送请求至前端控制器DispatcherServlet；（2） DispatcherServlet收到请求后，调用HandlerMapping处理器映射器，请求获取Handle；（3）处理器映射器根据请求url找到具体的处理器，生成处理器对象及处理器拦截器(如果有则生成)一并返回给DispatcherServlet；（4）DispatcherServlet通过HandlerAdapter处理器适配器调用处理器；（5）执行处理器(Handler，也叫后端控制器)；（6）Handler执行完成返回ModelAndView；（7）HandlerAdapter将Handler执行结果ModelAndView返回给DispatcherServlet；（8）DispatcherServlet将ModelAndView传给ViewResolver视图解析器进行解析；（9）ViewResolver解析后返回具体View；（10）DispatcherServlet对View进行渲染视图（即将模型数据填充至视图中）（11）DispatcherServlet响应用户。
Spring MVC的主要组键（1）前端控制器 DispatcherServlet（不需要程序员开发）作用：接收请求、响应结果 相当于转发器，有了DispatcherServlet 就减少了其它组件之间的耦合度。（2）处理器映射器HandlerMapping（不需要程序员开发）作用：根据请求的URL来查找Handler（3）处理器适配器HandlerAdapter注意：在编写Handler的时候要按照HandlerAdapter要求的规则去编写，这样适配器HandlerAdapter才可以正确的去执行Handler。（4）处理器Handler（需要程序员开发）（5）视图解析器 ViewResolver（不需要程序员开发）作用：进行视图的解析 根据视图逻辑名解析成真正的视图（view）（6）视图View（需要程序员开发jsp）View是一个接口， 它的实现类支持不同的视图类型（jsp，freemarker，pdf等等）
零配置文件搭建SpringMVC Start
1、pom文件：
4.0.0 com.wisely highlight_springmvc4 0.0.1-SNAPSHOT war 1.7 UTF-8 UTF-8 2.2 1.2 3.1.0 4.1.5.RELEASE 1.0.13 1.7.5 javax javaee-web-api 7.0 provided org.springframework spring-webmvc ${spring-framework.version} javax.servlet jstl ${jstl.version} javax.servlet javax.servlet-api ${servlet.version} provided javax.servlet.jsp jsp-api ${jsp.version} provided org.springframework spring-tx ${spring-framework.version} org.slf4j slf4j-api ${slf4j.version} log4j log4j 1.2.16 org.slf4j jcl-over-slf4j ${slf4j.version} ch.qos.logback logback-classic ${logback.version} ch.qos.logback logback-core ${logback.version} ch.qos.logback logback-access ${logback.version} com.fasterxml.jackson.dataformat jackson-dataformat-xml 2.5.3 commons-fileupload commons-fileupload 1.3.1 commons-io commons-io 2.3 org.springframework spring-test ${spring-framework.version} test junit junit 4.11 test org.apache.maven.plugins maven-compiler-plugin 2.3.2 ${java.version} ${java.version} org.apache.maven.plugins maven-war-plugin 2.3 false
2、MVC 配置Bean
import com.wisely.mypractice.interceptor.MyInterceptor;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import org.springframework.web.multipart.MultipartResolver;import org.springframework.web.multipart.commons.CommonsMultipartResolver;import org.springframework.web.servlet.config.annotation.*;import org.springframework.web.servlet.view.InternalResourceViewResolver;import org.springframework.web.servlet.view.JstlView;@Configuration//开启Mvc功能@EnableWebMvc//扫包@ComponentScan("com.wisely.mypractice")public class MyMvcConfig extends WebMvcConfigurerAdapter { //配置视图解析器 @Bean public InternalResourceViewResolver viewResolver(){ InternalResourceViewResolver viewResolver = new InternalResourceViewResolver(); viewResolver.setPrefix("/WEB-INF/classes/views/"); viewResolver.setSuffix(".jsp"); viewResolver.setViewClass(JstlView.class); return viewResolver; } //配置静态文件路径(直接访问) @Override public void addResourceHandlers(ResourceHandlerRegistry registry){ registry.addResourceHandler("/assets/**").addResourceLocations("classpath:/inde/"); } //将拦截器Bean纳入spring管理 @Bean public MyInterceptor demoInterceptor(){ return new MyInterceptor(); } //配置 拦截器 @Override public void addInterceptors(InterceptorRegistry registry){ registry.addInterceptor(demoInterceptor()); } //设置文件上传最大字节 @Bean public MultipartResolver multipartResolver(){ CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(); multipartResolver.setMaxUploadSize(1000000); return multipartResolver; }} 3、拦截器Bean
import org.springframework.web.servlet.ModelAndView;import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class MyInterceptor extends HandlerInterceptorAdapter { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response,Object handler){ long startTime = System.currentTimeMillis(); request.setAttribute("startTime",startTime); return true; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView){ long startTime = (Long)request.getAttribute("startTime"); request.removeAttribute("startTime"); long endTime = System.currentTimeMillis(); System.out.println("本次请求处理时间为："+ new Long(endTime-startTime) + "ms"); request.setAttribute("handlingTime",endTime - startTime); }} 3、配置 WebApplicationInitializer 实现类 (项目启动会自动加载该类的实现类)
import org.springframework.web.WebApplicationInitializer;import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;import org.springframework.web.servlet.DispatcherServlet;import javax.servlet.ServletContext;import javax.servlet.ServletException;import javax.servlet.ServletRegistration;public class WebInitializer implements WebApplicationInitializer { @Override public void onStartup(ServletContext servletContext) throws ServletException { AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext(); context.register(MyMvcConfig.class); context.setServletContext(servletContext); ServletRegistration.Dynamic servlet = servletContext.addServlet("dispatcher",new DispatcherServlet(context)); //映射路径 servlet.addMapping("/"); servlet.setLoadOnStartup(1); }}
4、拦截器
import org.springframework.web.servlet.ModelAndView;import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class MyInterceptor extends HandlerInterceptorAdapter { //请求前执行 @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response,Object handler){ long startTime = System.currentTimeMillis(); request.setAttribute("startTime",startTime); return true; } //请求后执行 @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView){ long startTime = (Long)request.getAttribute("startTime"); request.removeAttribute("startTime"); long endTime = System.currentTimeMillis(); System.out.println("本次请求处理时间为："+ new Long(endTime-startTime) + "ms"); request.setAttribute("handlingTime",endTime - startTime); }} 5、全局配置
import org.springframework.ui.Model;import org.springframework.web.bind.WebDataBinder;import org.springframework.web.bind.annotation.ControllerAdvice;import org.springframework.web.bind.annotation.ExceptionHandler;import org.springframework.web.bind.annotation.InitBinder;import org.springframework.web.bind.annotation.ModelAttribute;import org.springframework.web.context.request.WebRequest;import org.springframework.web.servlet.ModelAndView;@ControllerAdvicepublic class MyAdvice { //异常处理类( Exception.class 异常类型 ) 可以定义多个 @ExceptionHandler(value = Exception.class) public ModelAndView exception(Exception exception, WebRequest request){ ModelAndView modelAndView = new ModelAndView("error"); modelAndView.addObject("errorMessage",exception.getMessage()); return modelAndView; } //所有RequestMapping方法上 可以通过 ModelAttribute 形式获取值 @ModelAttribute public void addAttributes(Model model){ model.addAttribute("msg","额外信息"); } //忽略请求属性(只针对用Bean接受) @InitBinder public void initBinder(WebDataBinder webDataBinder){ webDataBinder.setDisallowedFields("id"); }} 6、Controller 控制器
import com.wisely.mypractice.domain.MyObj;import org.apache.commons.io.FileUtils;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.ModelAttribute;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.multipart.MultipartFile;import java.io.File;import java.io.IOException;@Controllerpublic class HelloController { @RequestMapping("/index") public String hello(){ return "index"; } @RequestMapping("/uploadToPage") public String uploadToPage(){ return "upload"; } @RequestMapping(value = "upload",method = RequestMethod.POST) public String upload(MultipartFile file){ try{ FileUtils.writeByteArrayToFile(new File("D:\\test\\"+file.getOriginalFilename()),file.getBytes()); return "ok"; }catch (IOException e){ e.printStackTrace(); return "wrong"; } } @RequestMapping("/advice") public String getSomething(@ModelAttribute("msg") String msg, MyObj obj){ System.out.println("id：" + obj.getId()); System.out.println("name：" + obj.getName()); throw new IllegalArgumentException("非常抱歉，参数有误来自@ModelAttribute：" + msg); }} TODO：
1)、页面我没有进行 copy 到帖子里 自己编写一些简单页面就可以了
2)、代码暂时没放到 GitHab 上 我研究一下 弄好了会修改帖子给出下载路径(只要配上页面 代码完全是好用的哦 )
3)、个人 QQ 1036943655 有什么技术上见解 可以一起互相学习 毕竟本人会的也不多
4)、所有知识点借鉴于 Spring Boot 实战 （书）