在Spring + Nextjs中以Excel的形式下载列表
在Spring + Nextjs中以Excel的形式下载列表
提问于 2022-09-06 16:03:21
我正在尝试从我的Nextjs前端点击一个按钮，下载一个excel列表。我的后端是用Spring编写的，我需要从这里发送文件，这样用户就可以在点击链接时下载它。
我的问题是：
如果在本例中，如果我想按一下按钮下载文件，那么
- 最佳实践是什么？
- ，返回类型和内容类型应该是什么？
我已经尝试过的东西，：通过改变内容类型和媒体类型。我想不知何故，我弄乱了触发API的内容类型和返回类型。
我的后端代码文件：
ExcelExporter.java
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFFont;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.List;
public class ExcelExporter {
private final XSSFWorkbook workbook;
private XSSFSheet sheet;
private final List<Debt> debts;
String[] columns = {"Reference", "Title", "Descrip", "Gateway", "Status", "Amount (USD)", "Paid", "Name"};
public ExcelExporter(List<Debt> debts) {
this.debts = debts;
workbook = new XSSFWorkbook();
}
private void writeHeaderLine() {
sheet = workbook.createSheet("Payment Report");
CellStyle headerCellStyle = workbook.createCellStyle();
// setting up header fonts
XSSFFont headerFont = workbook.createFont();
headerFont.setBold(true);
headerFont.setFontHeight(16);
// setting up header cell style
headerCellStyle.setFont(headerFont);
// header row creation
Row headerRow = sheet.createRow(0);
for(int col=0; col <columns.length; col++){
createCell(headerRow, col, columns[col], headerCellStyle);
}
}
private void createCell(Row row, int columnCount, String value, CellStyle style) {
sheet.autoSizeColumn(columnCount);
Cell cell = row.createCell(columnCount);
cell.setCellValue(value);
cell.setCellStyle(style);
}
private void writeDataLines() {
int rowIdx = 1;
CellStyle style = workbook.createCellStyle();
XSSFFont font = workbook.createFont();
font.setFontHeight(14);
style.setFont(font);
for (Debt debt : debts) {
Row dataRow = sheet.createRow(rowIdx++);
int columnCount = 0;
createCell(dataRow, columnCount++, debt.getRef(), style);
createCell(dataRow, columnCount++, debt.getTitle(), style);
createCell(dataRow, columnCount++, debt.getDescrip(), style);
createCell(dataRow, columnCount++, debt.getGateway(), style);
createCell(dataRow, columnCount++, debt.getStat(), style);
createCell(dataRow, columnCount++, debt.getAmount(), style);
createCell(dataRow, columnCount++, debt.getPaid(), style);
createCell(dataRow, columnCount++, debt.getName(), style);
}
}
public ByteArrayInputStream export() throws IOException {
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
try {
writeHeaderLine();
writeDataLines();
workbook.write(outputStream);
return new ByteArrayInputStream(outputStream.toByteArray());
}catch (IOException e){
throw new RuntimeException("fail To Import Data To Excel File: " + e.getMessage());
}
}
}主计长：
import lombok.RequiredArgsConstructor;
import org.apache.commons.io.IOUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
@RestController
@RequiredArgsConstructor
@RequestMapping("report")
public class ReportController {
@GetMapping(value = "export-to-excel", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)
public byte[] exportReport() throws IOException {
List<Debt> debtSummaries = new ArrayList<Debt>();
debt.add(new Debt("AA", "BB", "CC", "DD", "EE", "FF", "GG", "HH"));
debt.add(new Debt("AA", "BB", "CC", "DD", "EE", "FF", "GG", "HH"));
debt.add(new Debt("AA", "BB", "CC", "DD", "EE", "FF", "GG", "HH"));
debt.add(new Debt("AA", "BB", "CC", "DD", "EE", "FF", "GG", "HH"));
DateFormat dateFormatter = new SimpleDateFormat("yyyy-MM-dd_HH:mm:ss");
String currentDateTime = dateFormatter.format(new Date());
String headerKey = HttpHeaders.CONTENT_DISPOSITION;
String headerValue = "attachment; filename=PaymentReport_" + currentDateTime + ".xlsx";
HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders.add(headerKey, headerValue);
ExcelExporter excelExporter = new ExcelExporter(debtSummaries);
ByteArrayInputStream in = excelExporter.export();
return IOUtils.toByteArray(in);
}Debt.java
@Getter
@Setter
@AllArgsConstructor
public class Debt {
String ref;
String title;
String descrip;
String gateway;
String stat;
String amount;
String paid;
String name;
}回答 1
Stack Overflow用户
回答已采纳
发布于 2022-09-06 18:15:06
直接返回字节数组并不是正确的方法。我不能保证这是最好的方法。但你可以这样做。
import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.Resource;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
@RestController
@RequiredArgsConstructor
@RequestMapping("report")
public class ReportController {
@GetMapping(value = "export-to-excel", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)
public ResponseEntity<Resource> exportReport() throws IOException {
//Other actions you want to do...
ExcelExporter excelExporter = new ExcelExporter(debtSummaries);
ByteArrayInputStream in = excelExporter.export();
ByteArrayResource resource = new ByteArrayResource(in.readAllBytes());
return ResponseEntity.ok()
.headers(headers)
.contentLength(resource.contentLength())
.contentType(MediaType.parseMediaType("application/vnd.ms-excel"))
.body(resource);
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/73624888
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