最简单的EXCEL模板文件下载

之前所用的下载文件方法总是出现下载文件未知大小的问题，百思不得其解，最后使用该方法后，问题解决。

　　// 根目录为resources

　　private static final String filePath = "/excel/xxx.xlsx";

 　　/**
     * 下载EXCEL模板文件
     * 
     * @param response
     */
    @ApiOperation(value = "下载EXCEL模板文件", notes = "下载EXCEL模板文件", httpMethod = "GET", produces = "application/vnd.ms-excel", protocols = "HTTP/1.1")
    @RequestMapping(value = "/download-excel-model", method = RequestMethod.GET)
    public void downloadImportTemplate(HttpServletResponse response) {
        try {

            ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
            // 获取所有匹配的文件
            org.springframework.core.io.Resource[] resources = resolver.getResources(filePath);
            InputStream stream = resources[0].getInputStream();
            response.setContentType("application/vnd.ms-excel");
            response.setHeader("Content-Disposition", "attachment;filename=xxx.xlsx");
            IOUtils.copy(stream, response.getOutputStream());
            response.flushBuffer();

        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

==============================================================================================================

import org.apache.commons.io.IOUtils;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;

import javax.servlet.http.HttpServletResponse;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;

public class DownloadExcelModel {

    // 下载文件路径
    private String filePath;

    // 生成文件名称
    private String fileName;

    public DownloadExcelModel() {

    }

    public DownloadExcelModel(String filePath, String fileName) {
        this.filePath = filePath;
        this.fileName = fileName;
    }

    /**
     * <p>
     * 通用Excel导出方法,利用反射机制遍历对象的所有字段，将数据写入Excel文件中 <br>
     * 此版本生成2007以上版本的文件 (文件后缀：xlsx)
     * </p>
     */
    public void downloadExcelModel(HttpServletResponse response) throws Exception {

        ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        // 获取所有匹配的文件
        org.springframework.core.io.Resource[] resources = resolver.getResources(filePath);
        InputStream inputStream = resources[0].getInputStream();

        // response缓冲区重置
        response.reset();
        // 支持下载参数
        response.setContentType("application/vnd.ms-excel");
        // 设置浏览器响应头对应的Content-disposition
        response.setHeader("Content-Disposition", "attachment;filename=" + new String(fileName.getBytes(), StandardCharsets.ISO_8859_1) + ".xlsx");
        // 设置响应编码
        response.setCharacterEncoding("UTF-8");

        IOUtils.copy(inputStream, response.getOutputStream());
        response.flushBuffer();
    }

}