CODEWITHSUNDEEP
javacompiler-errorsjavac
tlorin
tlorin

Reputation: 1150

Classpath invalid flag - Java

I am using javac to compile a file called Rengine.jar.

I tried:

javac –classpath ./REngine.jar
javac –cp ./REngine.jar
javac ./REngine.jar
javac –classpath REngine.jar

And here are the errors that I got:

javac: invalid flag: –classpath
Usage: javac <options> <source files>
use -help for a list of possible options

javac: invalid flag: –cp
Usage: javac <options> <source files>
use -help for a list of possible options

javac: invalid flag: ./REngine.jar
Usage: javac <options> <source files>
use -help for a list of possible options

javac: invalid flag: –classpath
Usage: javac <options> <source files>
use -help for a list of possible options

I am not familiar with Java at all and I could not find an answer to this problem with a Google search. I precise that I am in the good directory and that I am using Mac OSX. My Java version is 1.8.0_20. Any advice would be much appreciated! :)

Upvotes: 0

Views: 30090

Answers (3)

Yassin
Yassin

Reputation: 13

specify the option and source file, try like this:

javac -classpath ./lib/* file.java

in case you have any problem try specifying which artifact the compiler will use:

javac -classpath ./lib/myjar.jar file.java

Upvotes: 0

KernelKoder
KernelKoder

Reputation: 746

Firstly, you cannot compile a .jar file. A .jar file is a collection of complied .java files (.class files). You are however able to run a .jar file if your manifest file is set up correctly.

The procedure is as follws:
Compile: 

javac MyClass.java

the above line creates MyClass.class

Create JAR with manifest file: 

jar cfe myJar.jar myClass myClass.class

Run JAR: 

java -jar myJar.jar

Upvotes: 4

SubOptimal
SubOptimal

Reputation: 22973

javac - the Java source compiler, will compile the Java source file *.java into JVM bytecode the class file *.class

To execute a Java program you need to call a class file with java YourClass.

The Jar file is a Java archive file. Which contains other files. For example class files. If you want to run a class from within the Jar file there a two way.

executable Jar

java –jar REngine.jar

This depends on the manifest file inside the Jar, which defines the main class which should be executed.

class inside a Jar file

java –cp REngine.jar package.YourClass

This would execute the class package.YourClass (assuming the class has a main method).

Upvotes: 1

Related Questions