问题
I am completely new to java and I need to just run an application I downloaded off the internet. The application in question is the "spinn3r" client found here: http://code.google.com/p/spinn3r-client/downloads/detail?name=spinn3r-client-3.4.06.tar.gz
I extracted the tar.gz and found a .jar file. I then ran:
java -jar applicationName.jar
I get the following error:
no main manifest attribute, in spinn3r-client-3.4.06.jar
How do I fix this?
回答1:
As @Alderath mentioned, this is primarily an API which you can use in your own applications. Nevertheless, the jar file also contains a test client which you can launch as follows:
$ java -cp spinn3r-client-3.4.06.jar com.spinn3r.api.Main
Usage: com.spinn3r.api.Main [OPTION]
Required params:
...
Since this it is not an executable jar file, you need to pass the required jar files and the class which contains the main method explicitly.
回答2:
For a JAR file to become executable, under META-INF/MANIFEST.MF, in your jar, you need to have this attribute:
Main-Class: youclassname.class
回答3:
Collect all your .java files and .class files (and anything else you want to include) together in a single directory. Using a text editor, create a file (say, myManifest) containing the following lines:
Manifest-Version: 1.0
Main-Class: MyMainClass
where MyMainClass is the name of the class containing the main method you want to use.
From the command line, execute the command:
jar cvfm myResult.jar myManifest *.java *.class
where myResult.jar is the jar file you are trying to create, myManifest is the file you created in step 2, and everything else is the files you want to include.
来源：https://stackoverflow.com/questions/15156562/cannot-run-java-application-main-not-found