如何在运行时下载Springboot生成的angular PDF文件

Question

我正试图在Springboot Service中下载一个运行时生成的PDF文件(使用iTextPDF生成的PDF(，并希望通过angular 6.0在新选项卡中打开该文件。我试着按照这个操作。如何下载在我的服务器(springboot(上生成的angular pdf文件？但得到错误为"加载PDF文档失败"。代码中有什么错误？

角度成分：

this.service.PrintPDF(this.quotations).subscribe((data: Blob) => {
var file = new Blob([data], { type: 'application/pdf' })
var fileURL = URL.createObjectURL(file);
// if you want to open PDF in new tab
window.open(fileURL); 
var a         = document.createElement('a');
a.href        = fileURL; 
a.target      = '_blank';
// a.download    = 'bill.pdf';
document.body.appendChild(a);
a.click();
},
(error) => {
console.log('getPDF error: ',error);
}
);

角度服务：

PrintPDF(quotations: Quotation[]) {
let url = this.PDF_URL;
var authorization = 'Bearer ' + sessionStorage.getItem("key");
const headers = new HttpHeaders({
'Content-Type': 'application/json',
responseType: 'blob',
"Authorization": authorization
});
return this.http.post<Blob>(url, quotations, {
headers: headers, responseType:'blob' as 'json'}).pipe(map(
(response) => {
return response;
},
(error) => {console.log(error.json());}
));

Springboot控制器：

@PostMapping(value = "/generatepdf")
public void downloadFile(@RequestBody List<QuotationDTO> quotationDTOs, HttpServletRequest request, HttpServletResponse response) {
try {
quotationService.GeneratePDF(quotationDTOs, request, response);
} catch (DocumentException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}

Springboot服务：

public String  GeneratePDF(java.util.List<QuotationDTO> quotationDTOs, HttpServletRequest request,
HttpServletResponse response) throws DocumentException, IOException {
response.setContentType("application/blob");
// Response header
response.setHeader("Pragma", "public");
response.setHeader("responseType", "blob");
response.setHeader("Content-Disposition", "attachment; filename="" + "Quotation" + """);
//        OutputStream os = response.getOutputStream();
Document document = new Document(PageSize.A4, 50, 50, 5 , 5);
String current = sdf.format(new Timestamp(System.currentTimeMillis())).toString();
String reportName = "report"+current;
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(<Path>));
document.open();
// Write Content
document.close();
PdfWriter.getInstance(document, response.getOutputStream());
return reportName+".pdf";
}

Answer 1

我找到了问题的解决方案。我试图从内存中发送PDF。现在在一个位置创建pdf，并从该位置发送阅读。不确定iTextPDF是否支持在内存中创建pdf。

Springboot服务：

public Resource GeneratePDF(java.util.List<QuotationDTO> quotationDTOs, HttpServletRequest request)
throws DocumentException, IOException {
Document document = new Document(PageSize.A4, 50, 50, 5 , 5);
String current = sdf.format(new Timestamp(System.currentTimeMillis())).toString();
String reportName = "report"+current;
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("PATH"));
document.open();
//Write PDF
document.close();
try {
Path filePath = this.fileStorageLocation.resolve(reportName+".pdf").normalize();
Resource resource = new UrlResource(filePath.toUri());
if (resource.exists()) {
return resource;
} else {
throw new MyFileNotFoundException("File not found " + reportName+".pdf");
}
} catch (MalformedURLException ex) {
throw new MyFileNotFoundException("File not found " + reportName+".pdf", ex);
}
}

Springboot控制器：

@PostMapping(value = "/generatepdf")
public ResponseEntity<Resource> downloadFile(@RequestBody List<QuotationDTO> quotationDTOs, HttpServletRequest request) {
try {
Resource resource = quotationService.GeneratePDF(quotationDTOs, request);
String contentType = null;
try {
contentType = request.getServletContext().getMimeType(resource.getFile().getAbsolutePath());
} catch (IOException ex) {
}
// Fallback to the default content type if type could not be determined
if(contentType == null) {
contentType = "application/octet-stream";
}
return ResponseEntity.ok()
.contentType(MediaType.parseMediaType(contentType))
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename="" + resource.getFilename() + """)
.body(resource);
} catch (DocumentException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

角度服务：

PrintPDF(quotations: Quotation[]) {
let url = this.PDF_URL;
var authorization = 'Bearer ' + sessionStorage.getItem("key");
let headerOptions = new HttpHeaders({
'Content-Type': 'application/json',
'Accept': 'application/pdf',
"Authorization": authorization
//   'Accept': 'application/octet-stream', // for excel file
});
let requestOptions = { headers: headerOptions, responseType: 'blob' as 'blob' };
this.http.post(url, quotations, requestOptions).pipe(map((data: any) => {
let blob = new Blob([data], {
type: 'application/pdf' // must match the Accept type
// type: 'application/octet-stream' // for excel 
});
var link = document.createElement('a');
link.href = window.URL.createObjectURL(blob);
// link.download = 'samplePDFFile.pdf';
link.target = '_blank';
link.click();
window.URL.revokeObjectURL(link.href);
})).subscribe((result: any) => {
});
}

Angular Component只是在调用Angular Service