springboot学习(九): 文件的上传下载和jsp页面的使用

﹏ヽ暗。殇╰゛Y 2022-04-16 06:06 88阅读 0赞

# 说明 #

由于工作的需要，在学习springboot时，学习了jsp的使用，最近又涉及到springboot的文件上传方式。找资料学习后，在这里记录总结下springboot的单个和多个文件的上传和下载及jsp的使用。

# 正文 #

## 一、jsp的使用 ##

通过Spring Initializr创建新的springboot项目，添加依赖：

<dependency>
    	<groupId>org.springframework.boot</groupId>
    	<artifactId>spring-boot-starter-tomcat</artifactId>
    	<scope>provided</scope>
    </dependency>
    <dependency>
    	<groupId>javax.servlet</groupId>
    	<artifactId>javax.servlet-api</artifactId>
    	<scope>provided</scope>
    </dependency>
    
    <dependency>
    	<groupId>javax.servlet</groupId>
    	<artifactId>jstl</artifactId>
    </dependency>
    
    
    <dependency>
    	<groupId>org.apache.tomcat.embed</groupId>
    	<artifactId>tomcat-embed-jasper</artifactId>
    	<scope>provided</scope>
    </dependency>

添加依赖后，在application.properties中配置文件的前缀和后缀：

spring.mvc.view.prefix=/WEB-INF/view/
    spring.mvc.view.suffix=.jsp
    #关闭默认模板引擎
    spring.thymeleaf.cache=false
    spring.thymeleaf.enabled=false

启动类继承SpringBootServletInitializer，重写configure方法：

@Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
    	return builder.sources(FilehandlingApplication.class);
    }

## 二、文件上传 ##

### 单个文件上传 ###

创建文件上传的jsp页面

在方法的中使用 MultipartFile作为参数类型

@RequestMapping(value = "/upload",method = RequestMethod.POST,consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
     public String fileUpload(@RequestParam("file") MultipartFile file) throws IOException {
          System.out.println(file.getOriginalFilename());
          File covertFile = new File("F:/StudyProject/springboot_studyII/filehandling/" + file.getOriginalFilename());
          covertFile.createNewFile();
          FileOutputStream fout = new FileOutputStream(covertFile);
          fout.write(file.getBytes());
          fout.close();
          return "file is upload successfully";
     }

## 使用ajax上传多个文件 ##

创建jsp页面，这里使用ajax异步上传，需要[jquery.js][]和[jquery.form.js][]插件 ：

表单元素

使用ajax异步上传

在上传方法中使用MultipartFile\[\]作为参数类型

@RequestMapping(value = "/upload/multi", method = RequestMethod.POST)
    public String mutliFileUplod(@RequestParam(value = "files") MultipartFile[] files){
        for(MultipartFile file : files){
            System.out.println(file.getOriginalFilename());
        }
        return "multiple files upload successfully";
    }

### 文件下载 ###

@RequestMapping(value = "/download", method = RequestMethod.GET)
    public ResponseEntity<Object> downloadFile() throws FileNotFoundException {
        String fileName = "C:/Users/wds/Desktop/test.txt";
        File file = new File(fileName);
        InputStreamResource resource = new InputStreamResource(new FileInputStream((file)));
    
        HttpHeaders headers = new HttpHeaders();
        headers.add("Content-Disposition",String.format("attachment;filename=\"%s\"",file.getName()));
        headers.add("Cache-Control","no-cache,no-store,must-revalidate");
        headers.add("Pragma","no-cache");
        headers.add("Expires","0");
    
        ResponseEntity<Object> responseEntity = ResponseEntity.ok().headers(headers).contentLength(file.length())
                .contentType(MediaType.parseMediaType("application/text")).body(resource);
        return responseEntity;
    }

可以通过参数指定文件的下载地址，访问方法结果如下图所示：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM2NTUzOTEz_size_16_color_FFFFFF_t_70]

源码地址：[https://github.com/Edenwds/springboot\_study/tree/master/filehandling][https_github.com_Edenwds_springboot_study_tree_master_filehandling]

参考资料：  
[https://howtodoinjava.com/spring-boot/spring-boot-jsp-view-example/][https_howtodoinjava.com_spring-boot_spring-boot-jsp-view-example]  
[https://www.tutorialspoint.com/spring\_boot/spring\_boot\_file\_handling.htm][https_www.tutorialspoint.com_spring_boot_spring_boot_file_handling.htm]

[jquery.js]: https://jquery.com/
[jquery.form.js]: https://github.com/jquery-form/form/blob/master/src/jquery.form.js
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpbmF0XzM2NTUzOTEz_size_16_color_FFFFFF_t_70]: /images/20220416/1c50022ca2fc48dea501c4985642b797.png
[https_github.com_Edenwds_springboot_study_tree_master_filehandling]: https://github.com/Edenwds/springboot_study/tree/master/filehandling
[https_howtodoinjava.com_spring-boot_spring-boot-jsp-view-example]: https://howtodoinjava.com/spring-boot/spring-boot-jsp-view-example/
[https_www.tutorialspoint.com_spring_boot_spring_boot_file_handling.htm]: https://www.tutorialspoint.com/spring_boot/spring_boot_file_handling.htm