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Spring boot实现文件上传功能

2024-07-14 08:41:22
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本文实例为大家分享了Spring boot实现文件上传的具体代码,供大家参考,具体内容如下

1. 创建一个Maven的web工程,然后配置pom.xml文件,增加依赖:

<dependency>  <groupId>org.springframework.boot</groupId>  <artifactId>spring-boot-starter-web</artifactId>  <version>1.0.2.RELEASE</version> </dependency> 

2. 在webapp目录下的index.jsp文件中输入一个表单:

<html> <body> <form method="POST" enctype="multipart/form-data" action="/upload">  File to upload: <input type="file" name="file"><br />  Name: <input type="text" name="name"><br /> <br />  <input type="submit" value="Upload">   Press here to upload the file! </form> </body> 

这个表单就是我们模拟的上传页面

3. 编写处理这个表单的Controller:

import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream;  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 FileUploadController {   @RequestMapping(value="/upload", method=RequestMethod.GET)  public @ResponseBody String provideUploadInfo() {   return "You can upload a file by posting to this same URL.";  }   @RequestMapping(value="/upload", method=RequestMethod.POST)  public @ResponseBody String handleFileUpload(@RequestParam("name") String name,    @RequestParam("file") MultipartFile file){   if (!file.isEmpty()) {    try {     byte[] bytes = file.getBytes();     BufferedOutputStream stream =       new BufferedOutputStream(new FileOutputStream(new File(name + "-uploaded")));     stream.write(bytes);     stream.close();     return "You successfully uploaded " + name + " into " + name + "-uploaded !";    } catch (Exception e) {     return "You failed to upload " + name + " => " + e.getMessage();    }   } else {    return "You failed to upload " + name + " because the file was empty.";   }  }  } 

4. 然后我们对上传的文件做一些限制,同时编写main方法来启动这个web :

import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.boot.context.embedded.MultiPartConfigFactory; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration;  import javax.servlet.MultipartConfigElement;  @Configuration @ComponentScan @EnableAutoConfiguration public class Application {   @Bean  public MultipartConfigElement multipartConfigElement() {   MultiPartConfigFactory factory = new MultiPartConfigFactory();   factory.setMaxFileSize("128KB");   factory.setMaxRequestSize("128KB");   return factory.createMultipartConfig();  }   public static void main(String[] args) {   SpringApplication.run(Application.class, args);  } } 

5. 然后访问http://localhost:8080/upload就可以看到页面了。

上面的例子是实现的是单个文件上传的功能,假定我们现在要实现文件批量上传的功能的话,我们只需要简单的修改一下上面的代码就行,考虑到篇幅的问题,下面只是贴出和上面不同的代码,没有贴出的说明和上面一样。:

1.新增batchUpload.jsp文件

<html> <body> <form method="POST" enctype="multipart/form-data"   action="/batch/upload">  File to upload: <input type="file" name="file"><br />  File to upload: <input type="file" name="file"><br />  <input type="submit" value="Upload"> Press here to upload the file! </form> </body> </html> 

2. 新增BatchFileUploadController.java文件:

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.ResponseBody; import org.springframework.web.multipart.MultipartFile; import org.springframework.web.multipart.MultipartHttpServletRequest;  import javax.servlet.http.HttpServletRequest; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.util.List;  /**  * Created by wenchao.ren on 2014/4/26.  */  @Controller public class BatchFileUploadController {   @RequestMapping(value="/batch/upload", method= RequestMethod.POST)  public @ResponseBody  String handleFileUpload(HttpServletRequest request){   List<MultipartFile> files = ((MultipartHttpServletRequest)request).getFiles("file");   for (int i =0; i< files.size(); ++i) {    MultipartFile file = files.get(i);    String name = file.getName();    if (!file.isEmpty()) {     try {      byte[] bytes = file.getBytes();      BufferedOutputStream stream =        new BufferedOutputStream(new FileOutputStream(new File(name + i)));      stream.write(bytes);      stream.close();     } catch (Exception e) {      return "You failed to upload " + name + " => " + e.getMessage();     }    } else {     return "You failed to upload " + name + " because the file was empty.";    }   }   return "upload successful";  } } 

这样一个简单的批量上传文件的功能就ok了,是不是很简单啊。

注意:上面的代码只是为了演示而已,所以编码风格上采取了随性的方式,不建议大家模仿。

参考资料:MultipartResolver实现文件上传功能

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持VeVb武林网。

1. MultipartResolver也可以实现文件上传功能。参考文章:


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