Springboot 返回文件给前端_springboot返回文件流给前端

首先导入数据到excel中

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<CrawlerModel> 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：

创建接口返回文件到前端： 

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")
@CrossOrigin
public class ExportConroller {
 
    @Autowired
    MallSearchService mallSearchService;
 
    @GetMapping("/export")
    public ResponseEntity<byte[]> 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

前端获取文件流：

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)
           }
        })