SpringBoot下载Excel文件时,报错文件损坏的解决方案

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <configuration>
                    <encoding>UTF-8</encoding>
                    <nonFilteredFileExtensions>
                        <nonFilteredFileExtension>xlsx</nonFilteredFileExtension>
                    </nonFilteredFileExtensions>
                </configuration>
            </plugin>

package com.zikoo.czjlk.utils; 
import com.zikoo.czjlk.exception.EmServerError;
import com.zikoo.czjlk.exception.EmServerException; 
import javax.servlet.Http.httpservletResponse;
import java.io.*;
import java.net.URLEncoder; 
public class FileUtils { 
    public static void download(HttpServletResponse response, String filePath, String fileName){
 
        try {
            response.setHeader("content-type", "application/octet-stream");
            response.setContentType("application/octet-stream");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName,"UTF-8"));
 
            InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream(filePath);
 
            writeBytes(is, response.getOutputStream());
        }catch (Exception e) {
            throw new EmServerException(EmServerError.FILE_OPERATION_ERROR);
        }
    }
 
    private static void writeBytes(InputStream is, OutputStream os) {
        try {
            byte[] buf = new byte[1024];
            int len = 0;
            while((len = is.read(buf))!=-1)
            {
                os.write(buf,0,len);
            }
        }catch (Exception e) {
            throw new EmServerException(EmServerError.FILE_OPERATION_ERROR);
        }finally {
            if(is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
 
            if(os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

public XResponse<Void> exportProject(@PathVariable("projectId") String projectId,
         HttpServletResponse response) throws Exception 

public void exportProject(@PathVariable("projectId") String projectId,
         HttpServletResponse response) throws Exception