How to send generated PDF from javascript to Servlet.

[GnanendraPonnala]

Hello Team,

I have generated pdf based user inputs through javascript using pdfmake library, now i have to send email with generated pdf to customers. I am able send mail with pdf using smpt.js library but due to some security concerns its not recommended. Now I am thinking to send/post the generated pdf to backend (servlet class ) & send using acs commons email api.

Tried with below scenarious,

1. I tried sending pdf as Base64 from js & decode the same in servlet using java.util.Base64. getDecoder.decode(String)  - getting Illegal exception.

2. attaching pdf object to formData() object (as key- value) sending to servlet through ajax, still getting data as empty.

Can please helpn me is there any to achieve this.

Thanks in Advance

[Manjunath_K · Accepted solution]

@GnanendraPonnala 

Please try below code & it will not throw any error in java while decrypting the base64 encrypted file content.

Javascript

var file = $('#file-input')[0].files[0];
var reader = new FileReader();
var fileContent;    //data to be sent in ajax request with attr name 'fileContent'

reader.onload = function(readerEvt, test){
        fileContent = btoa(readerEvt.target.result);
}

reader.readAsBinaryString(file);

Java :

String decryptedFileContent = new String(Base64.decodeBase64(request.getParameter("fileContent")));

[GnanendraPonnala]

Hi @Manjunath_K

correct me if I am wrong, I think above solution will work when we upload pdf file (any file) manually, but in my case pdf is getting generated dynamically based on user inputs on page. How can I send generated pdf to backend(java class), so that i can use it in email service api to send email with pdf.

Code responsible to download pdf on client-side -- 

pdfMake.createPdf(docDefinition).download();

 Instead of download, I want to send pdf to java, so that I can use it to send mail with pdf.

let me if you need more info.

Thanks

[Manjunath_K]

@GnanendraPonnala 

Instead of pdfMake.createPdf(this.docDefinition).download() try below approach, get base64 file content & decrypt base64 file content in java.

Javascript

const pdfDocGenerator  = pdfMake.createPdf(this.docDefinition);
pdfDocGenerator.getBase64((data) => {
  fileContent = data  //data to be sent in ajax request with attr name 'fileContent'
});

Java :

String decryptedFileContent = new String(Base64.decodeBase64(request.getParameter("fileContent")));