admin Today we will talk about a feature in Eclipse that lets you check Git revision history of a particular line. It can be very useful especially if you are working on large file with hundreds or thousands of lines of code. If you are one of the developers who work with legacy codebase, you are … Read more
I wrote a post sometime back regarding using Notepad++ as offline JSON validator. There I touched upon briefly on a couple of websites which I regularly use to format or validate JSON documents online. Those are https://jsonlint.com/ & http://jsonviewer.stack.hu/. I also mentioned that I prefer http://jsonviewer.stack.hu/ because it parses larger JSON files efficiently & doesn’t … Read more
I already wrote a post regarding a free tool for drawing sequence diagram by typing just text. But it lacked few features. Basically few days back, I was looking for some frame or boundary element that I can use to logically group some participants. I won’t say this requirement is part of standard UML sequence … Read more
If you are using JPA or Hibernate directly and got that exception while starting your application, there is one obvious reason for that. You forgot to add that table in MySQL database or any other database that you are using. But if the table is present, then most likely it is a database user permission … Read more
I have seen people getting confused about how a binary heap can be built in O(n) time complexity. There are online articles & videos regarding this. I will try to explain it in my own way as simply as possible. First thing first, a binary heap is a complete binary tree. All levels of complete … Read more
Well, practically there is not much difference. If you check Java doc, you will notice that Closeable interface extends AutoCloseable interface. But there is one difference & that explains the reason why AutoCloseable interface was introduced in Java 7. Closeable close() method can throw IOException only. And that made sense as you will be using … Read more
If you have come to this post, then you are facing xml parsing issue in Java. Caused by: org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog. at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203) One common issue for this is BOM character. So what is a BOM (BYTE ORDER MARK) character? When you have … Read more
Some of us need to create sequence diagrams while doing architecture design of product or a new feature. There are several online websites out there which can be used to draw sequence diagrams. Some of them are free & some of them are paid services. They support different features. Somewhere you can actually draw, somewhere … Read more
If you are here, that means probably you have encountered below error: Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:387) at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292) at sun.security.validator.Validator.validate(Validator.java:260) at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324) … Read more
Sometimes we need to draw a binary tree or graph online to explain related stuffs. I wanted to share a website where you can write your tree or graph definition in plain english & you will get a graphical representation of it. You will just have to define relations between the nodes in text, that’s … Read more