Spring MVC項(xiàng)目搭建
添加依賴
(省略)
Spring MVC配置類
@Configuration
@EnableWebMvc
@ComponentScan("com.sjx.springmvc")
public class MyMvcConfig extends WebMvcConfigurerAdapter{
@Bean
public InternalResourceViewResolver viewResolver(){
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/WEB-INF/classes/views/");
viewResolver.setSuffix(".jsp");
viewResolver.setViewClass(JstlView.class);
return viewResolver;
}
}
Web配置,實(shí)現(xiàn)WebApplicationInitializer接口代替web.xml文件
public class WebInitializer implements WebApplicationInitializer {
@Override
public void onStartup(ServletContext servletContext) throws ServletException {
AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
ctx.register(MyMvcConfig.class);
ctx.setServletContext(servletContext);
Dynamic servlet = servletContext.addServlet("dispatcher", new DispatcherServlet(ctx));
servlet.addMapping("/");
servlet.setLoadOnStartup(1);
}
}
Spring MVC的常用注解
@controller
@controller注解在類上,表明這個(gè)類為Spring MVC的Controller,并講Web請(qǐng)求映射到注解了@RequestMapping的方法上@RequestMapping
@RequestMapping是用來映射Web請(qǐng)求的的方法,可以注解在類上,方法上的@RequestMapping路徑會(huì)繼承類上的路基,并且produces屬性可以設(shè)置請(qǐng)求的媒體類型@ResponseBody
@ResponseBody可以注解類上也可注解在方法上,支持把返回值放入response體內(nèi),而不是返回一個(gè)頁面@RequestBody
@RequestBody注解在參數(shù)前,允許請(qǐng)求的參數(shù)在request體中,而不是直接放在鏈接地址的后面@PathVariable
@PathVariable用來接受路勁參數(shù),次注解用在參數(shù)前面,如pathvar/{str},可接受參數(shù)str@RestController
@RestController是一個(gè)組合注解,是@Controller和@ResponseBody的組合
@Controller
@RequestMapping("/anno")
public class DemoAnnoController {
@RequestMapping(produces = "text/plain;charset=UTF-8")
public @ResponseBody String index(HttpServletRequest request) {
return "url" + request.getRequestURI() + "can access";
}
// http://localhost:8080/springmvc1/anno/pathvar/sjx
@RequestMapping(value = "pathvar/{str}", produces = "text/plain;charset=UTF-8")
public @ResponseBody String demoPathVar(@PathVariable String str, HttpServletRequest request) {
return "url" + request.getRequestURI() + " can access str:" + str;
}
// http://localhost:8080/springmvc1/anno/requestParam?id=25
@RequestMapping(value = "/requestParam", produces = "text/plain;charset=UTF-8")
public @ResponseBody String passRequestParam(Long id, HttpServletRequest request) {
return "url" + request.getRequestURI() + " can access id:" + id;
}
@RequestMapping(value = "/obj", produces = "application/json;charset=UTF-8")
@ResponseBody
public String passObj(DemoObj obj, HttpServletRequest request) {
return "url" + request.getRequestURI() + " can access, obj id:" + obj.getId() + " obj name:" + obj.getName();
}
@RequestMapping(value = { "/name1", "/name2" }, produces = "text/plain;charset=UTF-8")
public @ResponseBody String remove(HttpServletRequest request) {
return "url: " + request.getRequestURL() + " can access";
}
}
Spring MVC的基本配置
攔截器配置
- 攔截器類
- 繼承HandlerInterceptorAdapter實(shí)現(xiàn)自定義攔截器
- 重寫preHandle方法,請(qǐng)求發(fā)生時(shí)執(zhí)行
- 重寫postHandle方法,請(qǐng)求結(jié)束是執(zhí)行
public class DemoInterceptor extends HandlerInterceptorAdapter {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
long startTime = System.currentTimeMillis();
request.setAttribute("startTime", startTime);
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
Long startTime = (Long) request.getAttribute("startTime");
Long currentTime = System.currentTimeMillis();
long handlerTime = currentTime - startTime;
System.out.println("一次請(qǐng)求的時(shí)間為" + handlerTime + "ms");
request.setAttribute("handlerTime", handlerTime);
}
}
- 配置
- 配置攔截器的Bean
- 重寫addInterceptors(InterceptorRegistry registry)方法,添加攔截器
@Configuration
@EnableWebMvc
@ComponentScan("com.sjx.springmvc")
public class MyMvcConfig extends WebMvcConfigurerAdapter{
@Bean
public InternalResourceViewResolver viewResolver(){
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/WEB-INF/classes/views/");
viewResolver.setSuffix(".jsp");
viewResolver.setViewClass(JstlView.class);
return viewResolver;
}
//自定義攔截器
@Bean
public DemoInterceptor handlerTimeInterceptor(){
return new DemoInterceptor();
}
//添加攔截器
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(handlerTimeInterceptor());
}
}
@ControllerAdvice
使用@ControllerAdvice注解可以將對(duì)于控制器的全局配置放在一起
- @ExceptionHandler 用于處理全局處理器中的異常
- @ModelAttribute 本來是用于將鍵值對(duì)綁定到Model里,這里用于讓全局的@RequestMapping都能接收到此鍵值對(duì)
//聲明一個(gè)全局通知 此注解包含了 @Component
@ControllerAdvice
public class ExceptionHandlerAdvice {
//攔截所有的異常 顯示error界面
@ExceptionHandler(value = Exception.class)
public ModelAndView exception(Exception exception, WebRequest request) {
ModelAndView view = new ModelAndView("error");// error界面
view.addObject("errorMessage", exception.getMessage());
return view;
}
//所有用@RequestMapping注解的方法 都能獲取這個(gè)鍵值對(duì)
@ModelAttribute
public void addAttribute(Model mode) {
mode.addAttribue("msg", "額外信息");
}
}
文件上傳配置
- 添加依賴
<!-- 文件上傳 -->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.2</version>
</dependency>
<!-- 簡(jiǎn)化文件操作 -->
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
</dependency>
- 上傳頁面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>文件上傳</title>
</head>
<body>
<div class="upload">
<form action="upload" method="post" enctype="multipart/form-data">
<input type="file" name="file"><br>
<input type="submit" value="上傳文件">
</form>
</div>
</body>
</html>
- 添加upLoad的ViewController
//集中處理跳轉(zhuǎn)頁面
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/toUpload").setViewName("/upload");
}
- 配置MultipartResolver
//配置MultipartResolver,用MultipartFile 接受文件上傳
@Bean
public MultipartResolver multipartResolver(){
CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver();
multipartResolver.setMaxUploadSize(1000000);
return multipartResolver;
}
- 控制器
@Controller
public class UploadController {
@RequestMapping(value = "upload", method = RequestMethod.POST)
public @ResponseBody String upload(MultipartFile file) {
try {
// 使用 commons-io包實(shí)現(xiàn)快讀文件寫入磁盤
FileUtils.writeByteArrayToFile(new File("e:/upload/" + file.getOriginalFilename()), file.getBytes());
return "success";
} catch (IOException e) {
e.printStackTrace();
return "fail";
}
}
}
