#hashcode

Interesting Links, 15 Sep 2016

It may be a little early to suggest that Eclipse is dead, but “The Fall of Eclipse” says it anyway, and says why. The Eclipse community would disagree, of course. User liste pointed out MariaDB4j, which is… MariaDB embedded into a jar, suitable for integration testing with MariaDB in a build tool. Sure, H2 and Derby exist, but this allows you to test against MySQL and MariaDB, because if you have to use MySQL in...

2 minute(s) read

Finding hash collisions in Java Strings

In ##java, a question came up about generating unique identifiers based on Strings, with someone suggesting that hashCode() would generate generally usable numbers, without any guarantee of uniqueness. However, duplicate hash codes can be generated from very small strings, with ordinary character sets – see this stackoverflow answer – and therefore I thought it’d be interesting to find other short strings with the same hash values. It was discussed how prone to collisions the Strings hashCode...

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Guava's Equivalence: strategy for equals()/hashCode()

Introduction Given a class C, if you want to implement ordering, you have two choices: Have your class implement Comparable<c> (or Comparable<x>, where X is a superclass of C). Define a Comparator<c> to use with this class (or a Comparator<x>, where X is a superclass of C). In fact, many classes in the JDK will have you supply a Comparator if your class...

4 minute(s) read