Springboot 返回文件给前端

package com.ds.crawler.search.service.thirdParty;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.util.Date;import java.util.List;import com.ds.model.CrawlerModel;import com.ds.model.CrawlerResultModel;import org.apache.poi.ss.usermodel.Cell;import org.apache.poi.ss.usermodel.Row;import org.apache.poi.ss.usermodel.Sheet;import org.apache.poi.xssf.usermodel.XSSFWorkbook;public  class ExportToExcel {    public static Boolean exportToExcel(List products){        // 创建工作簿对象        XSSFWorkbook workbook = new XSSFWorkbook();        // 创建工作表对象        Sheet sheet = workbook.createSheet("products");        // 创建表头行        Row header = sheet.createRow(0);        header.createCell(0).setCellValue("ID");        header.createCell(1).setCellValue("site");        header.createCell(2).setCellValue("name");        header.createCell(3).setCellValue("price");        header.createCell(4).setCellValue("unit");        header.createCell(5).setCellValue("time");        header.createCell(6).setCellValue("source");        header.createCell(7).setCellValue("type");        header.createCell(8).setCellValue("size");        header.createCell(9).setCellValue("color");        header.createCell(10).setCellValue("img");        header.createCell(11).setCellValue("material");        header.createCell(12).setCellValue("rank");        // 填充数据        int rowNum = 1;        for (CrawlerModel product : products) {            Row row = sheet.createRow(rowNum);            row.createCell(0).setCellValue(rowNum);            row.createCell(1).setCellValue(product.getSite()==null?"":product.getSite());            row.createCell(2).setCellValue(product.getName()==null?"":product.getName());            row.createCell(3).setCellValue(((product.getPrice()==null?"":product.getPrice().toString())));            row.createCell(4).setCellValue(product.getUnit()==null?"":product.getUnit());            row.createCell(5).setCellValue(product.getTime()==null?"":product.getTime());            row.createCell(6).setCellValue(product.getSource()==null?"":product.getSource());            row.createCell(7).setCellValue(product.getType()==null?"":product.getType());            row.createCell(8).setCellValue(product.getSize()==null?"":product.getSize().toString());            row.createCell(9).setCellValue(product.getColor()==null?"":product.getColor().toString());            row.createCell(10).setCellValue(product.getImg()==null?"":product.getImg().toString());            row.createCell(11).setCellValue(product.getMaterial()==null?"":product.getMaterial());            row.createCell(12).setCellValue(product.getRank()==null?"":product.getRank().toString());            rowNum++;        }        // 将数据写入Excel文件        FileOutputStream outputStream = null;        try {            outputStream = new FileOutputStream("products.xlsx");            workbook.write(outputStream);            workbook.close();            outputStream.close();            return true;        } catch (IOException e) {            throw new RuntimeException(e);        }    }}

之后就会看到到处的excel文件了：

package com.ds.crawler.search.controller;import com.ds.common.exception.BizCodeEnume;import com.ds.common.exception.RRException;import com.ds.common.result.Result;import com.ds.crawler.search.service.MallSearchService;import com.ds.crawler.search.service.thirdParty.ExportToExcel;import com.ds.model.CrawlerResultModel;import com.ds.model.SearchParam;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.CrossOrigin;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;import javax.servlet.http.HttpServletResponse;import java.io.File;import java.io.FileInputStream;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import javax.servlet.http.HttpServletResponse;import org.springframework.http.HttpHeaders;import org.springframework.http.HttpStatus;import org.springframework.http.MediaType;import org.springframework.http.ResponseEntity;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.GetMapping;@Slf4j@RestController@RequestMapping("/search/product")@CrossOriginpublic class ExportConroller {    @Autowired    MallSearchService mallSearchService;    @GetMapping("/export")    public ResponseEntity export(SearchParam param, HttpServletResponse response) throws IOException {//       1、 根据要求查询数据        CrawlerResultModel result = mallSearchService.search(param);        if (result!=null&&result.getProduct()!=null){//            2、 将数据导入excel           Boolean b = ExportToExcel.exportToExcel(result.getProduct());//           3、转为字节流返回给前端           if(b){               File file = new File("E:\\GonZuoShi\\java\\crawler\\crawler-es\\products.xlsx");               // 将Excel文件读取到字节数组中               FileInputStream fileInputStream = new FileInputStream(file);               byte[] bytes = new byte[(int) file.length()];               fileInputStream.read(bytes);               fileInputStream.close();               // 设置响应头               HttpHeaders headers = new HttpHeaders();               headers.setContentType(MediaType.parseMediaType("application/vnd.ms-excel"));               headers.setContentDispositionFormData("attachment", "products.xlsx");               // 返回响应实体               return ResponseEntity.ok()//                       .headers(headers)//                       .contentLength(bytes.length)                       .body(bytes);           }else{               //抛出异常               throw new RRException(BizCodeEnume.EXPORT_TO_EXCEPTION.getMsg(),BizCodeEnume.EXPORT_TO_EXCEPTION.getCode());           }        }else{            //抛出异常            throw new RRException(BizCodeEnume.EXPORT_TO_EXCEPTION.getMsg(),BizCodeEnume.EXPORT_TO_EXCEPTION.getCode());        }    }}

这样前端就收会收到一个二进制的文件流

使用axios 请求：

创建request：

exportExcel(data){    return request{        url:'....',        port:get,        data:data,       responseType:'arraybuffer',     }}

调用：

proxy.$api.downloadcode({site:store.state.siteName}).then(res=>{          const link=document.createElement('a');           // let blob = new Blob([res.data],{type: 'applicationnd.ms-excel'});    //如果后台返回的不是blob对象类型，先定义成blob对象格式          try {            let blob =   new Blob([res.data], { type: 'application/octet-stream' })    //如果后台返回的直接是blob对象类型，直接获取数据          // let _fileName = res.headers['content-disposition'].split(';')[1].split('=')[1]; //拆解获取文件名，          link.style.display='none';          // 兼容不同浏览器的URL对象          const url = window.URL || window.webkitURL || window.moxURL;          link.href=url.createObjectURL(blob);          link.download =`${store.state.siteName}.xlsx`;   //下载的文件名称          link.click();          window.URL.revokeObjectURL(url);  //  #URL.revokeObjectURL()方法会释放一个通过URL.createObjectURL()创建的对象URL. 当你要已经用过了这个对象URL,然后要让浏览器知道这个URL已经不再需要指向对应的文件的时候,就需要调用这个方法.           }catch(e){            console.log('下载的文件出错',e)           }        })

来源地址：https://blog.csdn.net/qq_63946922/article/details/129969894