Spring MVC小结

Spring MVC项目搭建

添加依赖

(省略)

Spring MVC配置类

@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,实现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注解在类上,表明这个类为Spring MVC的Controller,并讲Web请求映射到注解了@RequestMapping的方法上
@RequestMapping
@RequestMapping是用来映射Web请求的的方法,可以注解在类上,方法上的@RequestMapping路径会继承类上的路基,并且produces属性可以设置请求的媒体类型
@ResponseBody
@ResponseBody可以注解类上也可注解在方法上,支持把返回值放入response体内,而不是返回一个页面
@RequestBody
@RequestBody注解在参数前,允许请求的参数在request体中,而不是直接放在链接地址的后面
@PathVariable
@PathVariable用来接受路劲参数,次注解用在参数前面,如pathvar/{str},可接受参数str
@RestController
@RestController是一个组合注解,是@Controller和@ResponseBody的组合

@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")

    @ResponseBodypublic 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

拦截器配置

拦截器类
1. 继承HandlerInterceptorAdapter实现自定义拦截器
2. 重写preHandle方法,请求发生时执行
3. 重写postHandle方法,请求结束是执行

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("一次请求的时间为" + handlerTime + "ms");

        request.setAttribute("handlerTime", handlerTime);

    }

}

配置
1. 配置拦截器的Bean
2. 重写addInterceptors(InterceptorRegistry registry)方法,添加拦截器

@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;

    }

    //自定义拦截器

    @Bean

    public DemoInterceptor handlerTimeInterceptor(){

        return new DemoInterceptor();

    }

    //添加拦截器

    @Override

    public void addInterceptors(InterceptorRegistry registry) {

        registry.addInterceptor(handlerTimeInterceptor());

    }

}

@ControllerAdvice

使用@ControllerAdvice注解可以将对于控制器的全局配置放在一起

@ExceptionHandler 用于处理全局处理器中的异常
@ModelAttribute 本来是用于将键值对绑定到Model里,这里用于让全局的@RequestMapping都能接收到此键值对

//声明一个全局通知  此注解包含了

@Component

@ControllerAdvice

public class ExceptionHandlerAdvice {

    //拦截所有的异常 显示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 都能获取这个键值对

    @ModelAttribute

    public void addAttribute(Model mode) {

        mode.addAttribue("msg", "额外信息");

    }

}

文件上传配置

添加依赖

<!-- 文件上传 -->

<dependency>

  <groupId>commons-fileupload</groupId>

  <artifactId>commons-fileupload</artifactId>

  <version>1.2</version>

</dependency>

<!-- 简化文件操作 -->

<dependency>

  <groupId>commons-io</groupId>

  <artifactId>commons-io</artifactId>

  <version>2.4</version>

</dependency>

上传页面

<%@ 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>文件上传</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="上传文件">

  </form>

  </div>

</body>

</html>

添加upLoad的ViewController

//集中处理跳转页面

@Override

public void addViewControllers(ViewControllerRegistry registry) {

    registry.addViewController("/toUpload").setViewName("/upload");

}

配置MultipartResolver

//配置MultipartResolver,用MultipartFile 接受文件上传

@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包实现快读文件写入磁盘

            FileUtils.writeByteArrayToFile(new File("e:/upload/" + file.getOriginalFilename()), file.getBytes());

            return "success";

        } catch (IOException e) {

            e.printStackTrace();

            return "fail";

        }

    }

}

来源：http://www.jianshu.com/p/2cdc81ec15df

来自为知笔记(Wiz)

巴特西

Spring MVC小结

Spring MVC项目搭建

添加依赖

Spring MVC配置类

Web配置,实现WebApplicationInitializer接口代替web.xml文件

Spring MVC的常用注解

Spring MVC的基本配置

拦截器配置

@ControllerAdvice

文件上传配置

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