<plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>exec-maven-plugin</artifactId>
        <executions>
          <execution>
            <id>exec-cnpm-install</id>
            <phase>prepare-package</phase>
            <goals>
              <goal>exec</goal>
            </goals>
            <configuration>
              <executable>${cnpm}</executable>
              <arguments>
                <argument>install</argument>
              </arguments>
              <workingDirectory>${basedir}/src/main/webapp</workingDirectory>
            </configuration>
          </execution>
          <execution>
            <id>exec-cnpm-run-build</id>
            <phase>prepare-package</phase>
            <goals>
              <goal>exec</goal>
            </goals>
            <configuration>
              <executable>${cnpm}</executable>
              <arguments>
                <argument>run</argument>
                <argument>build</argument>
              </arguments>
              <workingDirectory>${basedir}/src/main/webapp</workingDirectory>
            </configuration>
          </execution>
        </executions>
      </plugin>

<!--copy文件到指定目錄下 -->
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-resources-plugin</artifactId>
        <configuration>
          <encoding>${project.build.sourceEncoding}</encoding>
        </configuration>
        <executions>
          <execution>
            <id>copy-spring-boot-webapp</id>
            <!-- here the phase you need -->
            <phase>validate</phase>
            <goals>
              <goal>copy-resources</goal>
            </goals>
            <configuration>
              <encoding>utf-8</encoding>
              <outputDirectory>${basedir}/src/main/resources/static</outputDirectory>
              <resources>
                <resource>
                  <directory>${basedir}/src/main/webapp/dist</directory>
                </resource>
              </resources>
            </configuration>
          </execution>
        </executions>
      </plugin>

package com.file.demo.springbootfile;
import com.file.util.ResultUtil;
import org.apache.commons.lang.exception.ExceptionUtils;
import org.apache.tomcat.util.http.fileupload.IOUtils;
import org.apache.tomcat.util.http.fileupload.util.Streams;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
/*
* springboot整合vue，文件上傳下載
* */
//上傳不要用@Controller,用@RestController
@RestController
@RequestMapping("/file")
public class FileController {
  private static final Logger logger = LoggerFactory.getLogger(FileController.class);
  //在文件中，不用/或者\最好，推薦使用File.separator
  private final static String fileDir="files";
  private final static String rootPath = System.getProperty("user.home")+ File.separator+fileDir+File.separator;
  /*
  * 文件上傳
  * */
  @RequestMapping("/upload")
  public Object uploadFile(@RequestParam("file")MultipartFile[] multipartFiles, final HttpServletResponse response, final HttpServletRequest request){
    File fileDir = new File(rootPath);
    /*
    * exists()：測試此抽象路徑名表示的文件是否存在
    * isDirectory()：檢查一個對象是否是文件夾
    * isFile()：判斷是否為文件，也可能是文件目錄
    * */
    if(!fileDir.exists() && !fileDir.isDirectory()){
      //檢查到文件不存在則創(chuàng)建
      fileDir.mkdir();//創(chuàng)建文件，一級
      fileDir.mkdirs();//創(chuàng)建多級
    }
    try{
      if(multipartFiles != null && multipartFiles.length > 0){
        for ( int i = 0;i<multipartFiles.length;i++){
          try{
            String storagePath = rootPath+multipartFiles[i].getOriginalFilename();
            logger.info("上傳的文件：" + multipartFiles[i].getName()+","+multipartFiles[i].getContentType()+","
                +multipartFiles[i].getOriginalFilename() + ",保持的路徑為：" + storagePath);
            Streams.copy(multipartFiles[i].getInputStream(), new FileOutputStream(storagePath), true);
          }catch (IOException e){
            logger.info(ExceptionUtils.getFullStackTrace(e));
          }
        }
      }
    }catch (Exception e){
      return ResultUtil.error(e.getMessage());
    }
    return ResultUtil.success("上傳成功！");
  }
  /*
  * 文件下載
  * */
  @RequestMapping("/download")
  public Object downkiadFile(@RequestParam String fileName,final HttpServletResponse response,final HttpServletRequest request){
    OutputStream os = null;
    InputStream is = null;
    try{
      //獲取輸出流rootPath
      os = response.getOutputStream();
      //重置輸出流
      response.reset();
      response.setContentType("application/x-download;charset=GBK");
      response.setHeader("Content-Disposition", "attachment;filename="+ new String(fileName.getBytes("utf-8"), "iso-8859-1"));
      //讀取流
      File f= new File(rootPath+fileName);
      is = new FileInputStream(f);
      if(is == null){
        logger.error("下載文件失敗，請檢查文件“"+ fileName +"”是否存在");
        return ResultUtil.error("下載附件失敗，請檢查文件“" + fileName + "”是否存在");
      }
      //復(fù)制文件
      IOUtils.copy(is,response.getOutputStream());
      //刷新緩沖
      response.getOutputStream().flush();
    }catch (IOException e){
      return ResultUtil.error("下載文件失敗,error:" + e.getMessage());
    }
    //文件的關(guān)閉在finally中執(zhí)行
    finally {
      {
        try {
          if(is != null){
            is.close();
          }
        }catch (IOException e){
          logger.error(ExceptionUtils.getFullStackTrace(e));
        }
        try{
          if(os != null){
            os.close();
          }
        }catch (IOException e){
          logger.info(ExceptionUtils.getFullStackTrace(e));
        }
      }
    }
    return null;
  }
}