SpringBoot+fileUpload获取文件上传进度

protected MultipartParsingResult parseRequest(HttpServletRequest request) throws MultipartException {
    String encoding = determineEncoding(request);
    FileUpload fileUpload = prepareFileUpload(encoding);
    try {
      List<FileItem> fileItems = ((ServletFileUpload) fileUpload).parseRequest(request);
      return parseFileItems(fileItems, encoding);
    }
    catch (FileUploadBase.SizeLimitExceededException ex) {
      throw new MaxUploadSizeExceededException(fileUpload.getSizeMax(), ex);
    }
    catch (FileUploadBase.FileSizeLimitExceededException ex) {
      throw new MaxUploadSizeExceededException(fileUpload.getFileSizeMax(), ex);
    }
    catch (FileUploadException ex) {
      throw new MultipartException("Failed to parse multipart servlet request", ex);
    }
}

import javax.servlet.http.HttpSession;
import org.apache.commons.fileupload.ProgressListener;
import org.springframework.stereotype.Component;

@Component
public class UploadProgressListener implements ProgressListener{

  private HttpSession session; 

  public void setSession(HttpSession session){ 
    this.session=session; 
    ProgressEntity status = new ProgressEntity(); 
    session.setAttribute("status", status); 
  } 

  /* 
   * pBytesRead 到目前为止读取文件的比特数 pContentLength 文件总大小 pItems 目前正在读取第几个文件 
   */ 
  @Override
  public void update(long pBytesRead, long pContentLength, int pItems) { 
    ProgressEntity status = (ProgressEntity) session.getAttribute("status"); 
    status.setpBytesRead(pBytesRead); 
    status.setpContentLength(pContentLength); 
    status.setpItems(pItems); 
  } 
}

import org.springframework.stereotype.Component;

@Component
public class ProgressEntity { 
  private long pBytesRead = 0L;  //到目前为止读取文件的比特数  
  private long pContentLength = 0L;  //文件总大小  
  private int pItems;        //目前正在读取第几个文件 

  public long getpBytesRead() { 
    return pBytesRead; 
  } 
  public void setpBytesRead(long pBytesRead) { 
    this.pBytesRead = pBytesRead; 
  } 
  public long getpContentLength() { 
    return pContentLength; 
  } 
  public void setpContentLength(long pContentLength) { 
    this.pContentLength = pContentLength; 
  } 
  public int getpItems() { 
    return pItems; 
  } 
  public void setpItems(int pItems) { 
    this.pItems = pItems; 
  } 
  @Override 
  public String toString() { 
    float tmp = (float)pBytesRead; 
    float result = tmp/pContentLength*100; 
    return "ProgressEntity [pBytesRead=" + pBytesRead + ", pContentLength=" 
        + pContentLength + ", percentage=" + result + "% , pItems=" + pItems + "]"; 
  } 
} 

import java.util.List; 
import javax.servlet.http.HttpServletRequest; 
import org.apache.commons.fileupload.FileItem; 
import org.apache.commons.fileupload.FileUpload; 
import org.apache.commons.fileupload.FileUploadBase; 
import org.apache.commons.fileupload.FileUploadException; 
import org.apache.commons.fileupload.servlet.ServletFileUpload; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.web.multipart.MaxUploadSizeExceededException; 
import org.springframework.web.multipart.MultipartException; 
import org.springframework.web.multipart.commons.CommonsMultipartResolver; 

public class CustomMultipartResolver extends CommonsMultipartResolver{

  @Autowired
  private UploadProgressListener uploadProgressListener;

  @Override
  protected MultipartParsingResult parseRequest(HttpServletRequest request) throws MultipartException {
    String encoding = determineEncoding(request);
    FileUpload fileUpload = prepareFileUpload(encoding);
    uploadProgressListener.setSession(request.getSession());//问文件上传进度监听器设置session用于存储上传进度
    fileUpload.setProgressListener(uploadProgressListener);//将文件上传进度监听器加入到 fileUpload 中
    try {
      List<FileItem> fileItems = ((ServletFileUpload) fileUpload).parseRequest(request);
      return parseFileItems(fileItems, encoding);
    }
    catch (FileUploadBase.SizeLimitExceededException ex) {
      throw new MaxUploadSizeExceededException(fileUpload.getSizeMax(), ex);
    }
    catch (FileUploadBase.FileSizeLimitExceededException ex) {
      throw new MaxUploadSizeExceededException(fileUpload.getFileSizeMax(), ex);
    }
    catch (FileUploadException ex) {
      throw new MultipartException("Failed to parse multipart servlet request", ex);
    }
  }

}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.web.MultipartAutoConfiguration;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.multipart.MultipartResolver;

import com.example.listener.CustomMultipartResolver;

/*
 * 将 spring 默认的文件上传处理类取消自动配置，这一步很重要，没有这一步，当multipartResolver重新指向了我们定义好
 * 的新的文件上传处理类后，前台传回的 file 文件在后台获取会是空，加上这句话就好了，推测不加这句话，spring 依然
 * 会先走默认的文件处理流程并修改request对象，再执行我们定义的文件处理类。（这只是个人推测）
 * exclude表示自动配置时不包括Multipart配置
 */
@EnableAutoConfiguration(exclude = {MultipartAutoConfiguration.class})

@Configuration
@ComponentScan(basePackages = {"com.example"})
@ServletComponentScan(basePackages = {"com.example"})
public class UploadProgressApplication {

/*
 * 将 multipartResolver 指向我们刚刚创建好的继承 CommonsMultipartResolver 类的自定义文件上传处理类
 */
@Bean(name = "multipartResolver")
public MultipartResolver multipartResolver() {
  CustomMultipartResolver customMultipartResolver = new CustomMultipartResolver();
  return customMultipartResolver;
}

public static void main(String[] args) {
  SpringApplication.run(UploadProgressApplication.class, args);
}
}

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.servlet.ModelAndView;

@Controller
@RequestMapping("/uploadProgress")
public class UploadController {

  @RequestMapping(value = "/showUpload", method = RequestMethod.GET)
  public ModelAndView showUpload() {
    return new ModelAndView("/UploadProgressDemo");
  }

  @RequestMapping("/upload")
  @ResponseBody
  public void uploadFile(MultipartFile file) {
    System.out.println(file.getOriginalFilename());
  }

}

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8"></meta>
  <title>测试</title>这里写代码片
</head>
<body>
  这是文件上传页面
  <form action="/uploadProgress/upload" method="POST" enctype="multipart/form-data">
    <input type="file" name="file"/>
    <br/>
    <input type="submit" value="提交"/>
  </form>
</body>
</html>