Java Command Line with External .Jar

Java command line with external .jar

Concatenate each jar file argument to cp with:

; on Windows
: on Linux or Mac

e.g.

java -cp <path>\TOOLS.jar;.;<path>\jar2.jar;<path>\jar3.jar HelloWorld

on newer JVMs (6+, I think) you can also use the * to append all JARs in a directory e.g.

java -cp .;<path>\*; HelloWorld

To go a step further and create a single packaged executable see this question.

Compile java program in command line with external .jar

when you are executing below line, you are getting the below error right ?

javac -cp paillier.jar CoupleGen.java

Error: Could not find or load main class CoupleGen

That means compiler is looking for the CouplenGen.java in paillier.jar. Actually CoupleGen is outside of the jar file.

Run a JAR file from the command line and specify classpath

When you specify -jar then the -cp parameter will be ignored.

From the documentation:

When you use this option, the JAR file is the source of all user classes, and other user class path settings are ignored.

You also cannot "include" needed jar files into another jar file (you would need to extract their contents and put the .class files into your jar file)

You have two options:

1. include all jar files from the lib directory into the manifest (you can use relative paths there)
2. Specify everything (including your jar) on the commandline using -cp:
   
   java -cp MyJar.jar:lib/* com.somepackage.subpackage.Main

How to run Java program in terminal with external library JAR

You can do :

1) javac -cp /path/to/jar/file Myprogram.java

2) java -cp .:/path/to/jar/file Myprogram

So, lets suppose your current working directory in terminal is src/Report/

javac -cp src/external/myfile.jar Reporter.java

java -cp .:src/external/myfile.jar Reporter

Take a look here to setup Classpath

External jar files are not detected when compiled using cmd.?

use classpath (-cp)

javac -cp %YOUR_JAR_LOCATION% mail.java

Example :

javac -cp ".:./jars/mail.jar" helloworld.java
java -cp ".:./jars/mail.jar" helloworld

For Windows, ":" should be replaced with ";" and make sure your jar file path is correct.

Adding external dependencies to a jar file through the command line

You're not understanding what the classpath is. The classpath is a collection of jar files and directories where Java looks for classes (and other resources loaded by the class loader).

If a program uses the class com.foo.Bar, what must be in the classpath is not the file /somedirectory/com/foo/Bar.class. What must be in the classpath is the directory /somedirectory. Or the jar file containing that class.

From that base directory or jar file, the class loader will then look for a file corresponding to the class name:

com.foo.Bar --> com/foo/Bar.class

This is essential, because it allows Java to have access to hundreds of classes at once, without having to list those hundreds of class files in the classpath. All you need in the classpath is the directory or jar containing those hundreds of classes.

Also note that /usr/lib/jvm/java-8-jdk/jre/lib/* must not be inthe classpath either. Java knows where to find the libraries of the JRE itself.

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