1.controller层,value中的名字是自定义的，在controller层写之前要建好query和service层和vo层，如果不知道上述是什么意思，请再学习一下springMvc ，在这就不一一赘述。

 @PostMapping(value = "expoet")
 @ApiOperation(value = "导出", notes = "导出", produces = MediaType.APPLICATION_JSON_VALUE)
    public void export(@RequestBody TestQuery query, HttpServletResponse response) throws IOException {
        TestService.export(query, response);
    }

2.service层

/**
 *
 *导出
 *
 **/ 
void export(TestQuery query, HttpServletResponse response) throws IOException;

3.impl层，实体类，在这用到的 getExcelOutputStream()是自己封装的方法，后面加文件名和格式

 @Override
    public void export(TestQuery query, HttpServletResponse response) throws IOException {
        //设置返回文件名称和格式
        getExcelOutputStream("导出表", response);
        if (CollectionUtils.isNotEmpty(query)) {
            try (OutputStream outputStream = response.getOutputStream()) {
                EasyExcel.write(outputStream, TestVo.class)
                        .sheet("导出表").doWrite(query);
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
    }

4.getExcelOutputStream()方法，主要解决用utf-8返回防止乱码

/**
     * 导出文件时为Writer生成OutputStream
     * @param fileName: 文件名称
     * @param response:
     */
    public static void getExcelOutputStream(String fileName,
                                            HttpServletResponse response) throws IOException {
        try {
            fileName = URLEncoder.encode(fileName, "UTF-8");
            response.setContentType("application/vnd.ms-excel");
            response.setCharacterEncoding("utf8");
            response.setHeader("Content-Disposition", "attachment; filename=" + fileName + ".xlsx");
            response.setHeader("Pragma", "public");
            response.setHeader("Cache-Control", "no-store");
            response.addHeader("Cache-Control", "max-age=0");
//            response.setHeader("content-Type", "application/vnd.ms-excel");
        } catch (IOException e) {
            throw new IOException("导出excel表格失败!", e);
        }
    }

5.vo层，这里是TestVo，导出的字段要加一个注释

@ExcelProperty(value = "名称")
private String name;

这样用postman调用就可以生成excel表格了。当然导出的方法千千万，这只是其中一种最简单的。

共勉！