notes on core java in java

This deals with SQL. Left outer join preserves the unmatched rows from the first (left) table, joining them with a NULL row in the shape of the second (right) table. In the context of Core Java, it’s important to note that Java itself is a programming language and does not directly deal with SQL or database … Read more

JAR files (Java ARchive) allows aggregating many files into one, it is usually used to hold Java classes in a library. WAR files (Web Application aRchive) stores XML, java classes, and JavaServer pages for Web Application purposes. In Java, JAR (Java Archive) and WAR (Web Application Archive) files are both archive file formats, but they … Read more

Initiate, pull, branch, merge, commit, push. (Init) Make your own repository. (Pull) Download an existing repository from a url. (Branch / Merge )Make revisions. Commit then push your modifications. It seems like there might be a misunderstanding in your question. The question is related to Core Java, but the topic you’re asking about, the version … Read more

Tiers are the physical units of separation or deployment, while layers are the logical units of separation. Imagine that you’re designing an e-commerce website. A 3 tier architecture would consist of web pages, a web server and a database, with the corresponding 3 layers being the “Presentation”, “Business Logic” and “Database” layers. If you take … Read more

In general, unchecked exceptions represent defects in the program (bugs), which are normally Runtime exceptions. Furthermore, checked exceptions represent invalid conditions in areas outside the immediate control of the program. Explain Checked Exceptions and Unchecked Exceptions with examples Unchecked exceptions : represent defects in the program (bugs) – often invalid arguments passed to a non-private … Read more