Each December for the past several years, Advent of Code has presented a series of 25 daily programming challenge, with each problem adding to a Christmas-themed narrative. I think I'd seen references to AoC in the past but hadn't paid it any mind. This year, my team at work is evaluating Kotlin for adoption in our Android Java codebase, so a ( Read more... )

I had a thought at work the other day. Java has a strict one-parent-class rule. Philosophically, this is a good match in domains like taxonomic biology (a phylum is in one kingdom, a genus is in one family). But it's a terrible match in domains like cooking. A soup inherits flavors from many sources. You can add meat to what was originally a ( Read more... )

The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files.

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If a poor and despised Indian tried to get a job at a company testing Java software they would throw him out with a ClassCasteException.

I saw some typo Java code in my CVS update today which called throw null. I wondered just what that would do. null can be cast to any object, so I thought it might get caught by the first catch clause. Alternatively, I thought it might escape all catch clauses (dangerous!). The answer?

try ( Read more... )

Save me Edsgar! I just wished I could use a goto statement in Java. My code's primary purpose is to take a bunch of fixed-width data and save it to another file in a tab-delimited format. I decided to add the ability to save the layout. If the layout file already exists, I prompt the user with a Yes/No/Cancel dialog to overwrite. If they ( Read more... )

At work we use iText, a free library for manipulating PDFs. The library's author makes his money by giving away cool software that's complicated enough that developers are motivated to buy the book so they can use it well. We just bought said book, and I want royalties:


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Running JVM 1.4.2_08:
System.out.println("1 + --0 = " + new BigDecimal("1").add(new BigDecimal("--0")));
1 + --0 = 1
System.out.println("Int " + new BigDecimal("--00").intValue());
Int -1
System.out.println("Double " + new BigDecimal("--0").doubleValue());
ArrayIndexOutOfBoundsException: -1
System.out.println("BigDecimal " + new BigDecimal("--0"). ( Read more... )