Run java without specifying classpath on the command line

问题

I've specified the main class and classpath for a java program in the .jar file manifest, but occasionally I want to run a different class from the one specified by the Main-Class attribute. Can I get java to launch this class while still pulling the classpath from the manifest, so that I don't have to specify the whole thing on the command line with -cp?

回答1:

Just put the jar file on the command line with -cp; Java will then observe the classpath attribute within the manifest, even though you're not using -jar:

java -cp app.jar MyOtherClass

来源：https://stackoverflow.com/questions/7637820/run-java-without-specifying-classpath-on-the-command-line