SpringMVC笔记

MVC

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>6.0.10</version>
</dependency>

Controller

页面

@Controller   //直接添加注解即可
public class HelloController {

    @RequestMapping("/index")   //直接填写访问路径
    public ModelAndView index(){
        ModelAndView modelAndView = new ModelAndView("index");
        modelAndView.getModel().put("arg", "value");   //将name传递给Model
        return modelAndView;
          //返回后会经过视图解析器进行处理
    }

    @RequestMapping(value = "/index")
    public String index(Model model){  //这里不仅仅可以是Model，还可以是Map、ModelMap
        model.addAttribute("arg", "value");
        return "index";
    }
}

重定向

@RequestMapping("/index")
public String index(){
    return "redirect:page";
}

请求转发

@RequestMapping("/index")
public String index(){
    return "forward:home";
}

Bean的Web作用域

Bean的作用域：

1. Singleton
2. Prototype
3. Request HTTP请求产生新实例，结束后Bean消失
4. Session 每一个会话
5. Global Session

RESTFul

一种设计风格。RESTful风格的设计允许将参数通过URL拼接传到服务端。

http://localhost:8080/mvc/index/13579

@RequestMapping("/index/{str}")
public String index(@PathVariable String str) {
    System.out.println(str);
    return "index";
}

文件上传

public class MainInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    ...

    @Override
    protected void customizeRegistration(ServletRegistration.Dynamic registration) {
          // 直接通过registration配置Multipart相关配置，必须配置临时上传路径，建议选择方便打开的
        // 同样可以设置其他属性：maxFileSize, maxRequestSize, fileSizeThreshold
        registration.setMultipartConfig(new MultipartConfigElement("/path/to/save"));
    }
}

Controller模板

@RequestMapping(value = "/upload", method = RequestMethod.POST)
@ResponseBody
public String upload(@RequestParam MultipartFile file) throws IOException {
    File fileObj = new File("filename.png");
    file.transferTo(fileObj);
    System.out.println("用户上传的文件已保存到："+fileObj.getAbsolutePath());
    return "文件上传成功！";
}

前端模板

<div>
    <form action="upload" method="post" enctype="multipart/form-data">
        <input type="file" name="file">
        <input type="submit">
    </form>
</div>