Java jar file run
Dhttp.proxyPassword= specifies proxy password. Set it if the proxy server requires authentication. For example: -Dhttp.proxyHost=8080 -Dhttp.proxyUser= specifies proxy username. 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.
#Java jar file run how to
That’s all for how to run jar file in java with single entry point, different entry points and without any entry point at all using java classpath.Many jar files are "runnable". All you need to do it add the jar to class path and then execute the class like a normal java class with main java -cp MyProject.jar It seems confusing but solution is real simple. What if we don’t want to change the entry point but want to execute another class from jar file. Now when you will run the jar, it will execute the changed entry class. Note that warning is because of duplicate entries and manifest file can have only one entry for each meta property, but it still updates the entry point by updating the manifest file. Manifest and in the META-INF/MANIFEST.MF entry in the jar file. That blank lines separate individual sections in both your WARNING: Duplicate name in Manifest: Main-Class.Įnsure that the manifest does not have duplicate entries, and
#Java jar file run update
Then run the below command to update the entry jar uvfm MyProject.jar META-INF/MANIFEST.MF We will rename the manifest.txt to MANIFEST.MF and put it inside META-INF directory. Since manifest file is located at META-INF/MANIFEST.MF. So we can use the jar command to update the manifest file.įor updating a file using jar command, file structure should be similar otherwise it will add new file to another directory. What if my project has multiple entry points and I want to change the entry point without creating the jar again. That’s great when we have single class with main method. Run Jar File from command java -jar MyProject.jar Now we are ready to run jar file through command line. Manifest-Version and Created-By entries are added by jar command. Now when I unpack and check the contents of MANIFEST.MF file, it contains following data. Now we will use jar command to create jar file with our manifest file jar cvfm MyProject.jar manifest.txt comĪdding: com/journaldev/(in = 0) (out= 0)(stored 0%)Īdding: com/journaldev/test/(in = 0) (out= 0)(stored 0%)Īdding: com/journaldev/test/MyTest.class(in = 444) (out= 303)(deflated 31%)Īdding: com/journaldev/util/(in = 0) (out= 0)(stored 0%)Īdding: com/journaldev/util/MyUtil.class(in = 444) (out= 304)(deflated 31%)