Often features of an application can be isolated and tested just by launching them as standalone apps meaning the build process is skipped entirely. This can be a very productive way to develop but the more complex the area being tested and the more integrated it is into other parts of the app then the more complex (and therefore time consuming) it is to maintain the test harness that allows the test to function.
For some features the test harness required is such that an entire build is necessary. In these cases the build time is a key factor.
JWrapper strives to keep build times as low as possible by using precompiled components, pre-compressed archives and caching. A full build of a simple app in JWrapper from Jars to signed executables for Windows, Linux and MacOS (both online and JRE-bundled offline) takes as little as 24 seconds on a modern laptop. However, when building for development purposes you may be willing to skip some release-level features in order to save time.
Luckily you can ask JWrapper to skip some time consuming steps that typically aren't required for a development build. By running your JWrapper build with 'false' after the JWrapper XML file argument (e.g. java -jar jwrapper-xxx.jar myJWrapperXML.xml false) JWrapper will skip some compression in its archive building and also skip timestamps when signing your apps. Just adding this switch leaves you with slightly larger executables and non-timestamped signatures but for the example above brings the build down to just 12 seconds, twice as fast as a full release build.
If you want to save even more time you may be able to skip one or more platforms and build for just your own OS. The same simple app building in dev-mode for just Window takes only 7 seconds (the bulk of which is actually the JVM startup time).
More Reductions in Java Development Round Trip Time
JRebel offers a commercial plugin that has some great features and aims to save you from having to redeploy more than you need to. There may be times when you still need to do a full build but even if you can avoid building and speed up round trips in a part of your development time it still makes sense. They even have an ROI calculator so you can figure out how much time (and therefore money) you are saving.
The expense of time spent waiting for builds is easily calculated but reducing round trip times can be even more important and significant depending on your project's critical path, if it takes you half an hour every time you want to build and test something but everyone else is waiting for that bug to get fixed then the benefits of a reduced round trip time are multiplied.
Saving Time in Web Development
Having developed SimpleHelp we know how much latency can affect productivity so a combination of tools like these that can turn minutes of turnaround into seconds can have a big impact on the speed of development and consequently your business.