For example: -Dhttp.proxyHost=192.168.1.1 -Dhttp.proxyPort= specifies a proxy port. Proxy options -Dhttp.proxyHost= specifies a proxy server if you want to use http though a proxy server. Increase it to, for example, 512 MB with the option -Xmx512m. The default value is 64 MB which is often too small. This is the maximum memory capacity of the Java application. Memory options -Xmx is the only memory option which really matters. See Java documentation for more information. The following are commonly used options for the Java VM. For example, for to run JOSM, type commands like this: It's not so hard even if you don't have any experience of command lines. Some Java applications (for example, mkgmap.jar) cannot run without terminals. This way is a more basic fundamental approach which you can use on any operating system. Think twice before you set up your system to start jar files automatically by just clicking-this would work with all downloaded jar files then (also with accidental, malicious downloads)! Better use the command line or a manually built link/script.

Firstly, you'll need Java installed as detailed above, and with the necessary operating system hooks enabled, and these may not be available for some operating systems.

The file contains details of which Java class files to run by default, and the application just starts up. This means you can simply double-click the file on many operating systems.