CSV handling in Java

These past days i've been trying to load CSV files in Java. Used opencsv with some degree with success, however some fields were still misinterpreted .
Next an old friend by name of FasterXML/jackson came to the rescue, however i was still having some issues.
Last but not least on stackoverflow.com (where else) i came across https://simpleflatmapper.org/ and with something like:

CsvParser.separator(';')

   .mapTo(MyClass.class)

   .headers("my","headers","list")

   .iterator(new File(filepath));

I was up and running .

Note : If you find MalformedInputException check if your input is UTF-8 , more info here  http://biercoff.com/malformedinputexception-input-length-1-exception-solution-for-scala-and-java/

Generating PDF from a webpage using JavaScript

A requisite for a project i was working on a while back was to generate a reader like version of a webpage and export it to PDF.
I started by getting a printable format for the webpage which was not that difficult, just removing some classes and adding some css with Jquery.

Now came the fun part.

What if i could do all of this on the client side, using JavaScript.

Imagine you're the server and your project manager is the browser. What a fine day it would be when a project manager interrupts you with something he/she could do.
Moreover i would save some cpu cycles on the server and learn something new in the process.

So with the help of stackoverflow my journey began.
What do i need :

• Something to generate PDF in JavaScript -I came across jsPDF it has a very simple API and is really simple to use.
• Now i need something that can make like a screenshot of the element . Again with the help of StackOverflow i came across  - html2canvas .

Using both together is really simple

        html2canvas($("#canvas"), {
            onrendered: function(canvas) {         
                var imgData = canvas.toDataURL(
                    'image/png');              
                var doc = new jsPDF('p', 'mm');
                doc.addImage(imgData, 'PNG', 10, 10);
                doc.save('sample-file.pdf');
            }
        });

From post at stackoverflow.com

I do recommend taking a look at the of jsPDF Examples
If your files are coming out a bit on the large size you may also compress it -jsPDF constructor has a flag to enable compression. My pdf came from about 14 megs to 240kb.

 The trickiest bit happens when your image is bigger than a page. In that case you must treat your image like a sliding window, effective splitting the image through several pages. A good example code can be found on

• jsPDF/issues/434
• stackoverflow.com questions

Hopefully you find this useful, i have tried to gather most of the sources i went through to learn.
Credit to the devs @ stackoverflow .


And thanks to those that :

How to convert Pem certificate to Hex string in Java (a stackoverflow conglumerate)

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//******************************************************************* // Welcome to CompileJava! // If you experience any issues, please contact us ('More Info') --> //******************************************************************* import java.lang.Math; // headers MUST be above the first class import java.util.Base64; // one class needs to have a main() method public class HelloWorld { public static String toHexString( byte[] bytes ) { StringBuffer sb = new StringBuffer( bytes.length*2 ); for( int i = 0; i < bytes.length; i++ ) { sb.append( toHex(bytes[i] >> 4) ); sb.append( toHex(bytes[i]) ); } return sb.toString(); } private static char toHex(int nibble) { final char[] hexDigit = { '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F' }; return hexDigit[nibble & 0xF]; } // arguments are passed using the text field below this editor public static void main(String[] args) { String pemText="-----BEGIN CERTIFICATE-----"+ "blablabla"+ "-----END CERTIFICATE-----"; byte[] certificateBytes = Base64.getDecoder().decode( pemText.replaceAll("-----(BEGIN|END) CERTIFICATE-----", "").replaceAll("\n", "").getBytes() ); System.out.println(toHexString(certificateBytes)); } }