06点睛Spring MVC 4.1-文件上传

6.1 文件上传

• 在控制器参数使用@RequestParam("file") MultipartFile file接受单个文件上传;
• 在控制器参数使用@RequestParam("file") MultipartFile[] files接受多个文件上传;
• 通过配置MultipartResolver来配置文件上传的一些属性;

6.2 示例

• 增加和上传和文件操作的依赖到maven

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.3</version>
</dependency>
<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.3.1</version>
</dependency>

• 上传控制器

package com.wisely.web;

import java.io.File;
import java.io.IOException;

import org.apache.commons.io.FileUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

@Controller
public class UploadController {

    //接受多个文件上传使用@RequestParam("file") MultipartFile[] files
    @RequestMapping(value = "/upload",method = RequestMethod.POST)
    public @ResponseBody String upload(@RequestParam("file") MultipartFile file) {

            try {
    FileUtils.writeByteArrayToFile(new File("e:/"+file.getOriginalFilename()),
                                                               file.getBytes());
                return "ok";
            } catch (IOException e) {
                e.printStackTrace();
                return "wrong";
            }


    }

}

• 文件上传所需配置

@Configuration
@ComponentScan("com.wisely")
@EnableWebMvc
public class DemoMVCConfig extends WebMvcConfigurerAdapter {

    @Bean
    public UrlBasedViewResolver viewResolver(){
        UrlBasedViewResolver resolver = new UrlBasedViewResolver();
        resolver.setPrefix("/WEB-INF/views/")
        resolver.setSuffix(".jsp");
        resolver.setViewClass(JstlView.class);
        return resolver;
    }
    //注册拦截器
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(demoInteceptor());
    }
    //自定义拦截器
    @Bean
    public DemoInteceptor demoInteceptor(){
        return new DemoInteceptor();
    }

    //静态资源映射
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/js/**").addResourceLocations("/js/");
    }
    //文件上传设置--在此处
    @Bean
    public MultipartResolver multipartResolver() {
        CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver();
        multipartResolver.setMaxUploadSize(1000000);
        return multipartResolver;
    }
}

• 页面代码

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