GSON“NoClassDefFoundError com/google/gson/Gson”

Question

I'm trying to get gson to work on a java project, but get the above error every time I run it. I am not using any flash IDEs, just vim and every question I have seen related to my question is to do with eclipse and their deployment settings. I hope someone can spot something wrong in my tactics.

Note: I have the gson jar file renamed to gson.jar

To compile my code: javac myProgram.java -cp gson.jar
and to run my code: java myProgram -cp gson.jar

The program will compile fine, but it will throw an error as soon as I attempt to initiliaze a Gson object.

Full error: Exception in thread "main" java.lang.NoClassDefFoundError: com/google/gson/Gson

Answer 1

I believe you have the javac and java argument order mixed up. The syntax is:

javac <options> <source files>

and

java [-options] class [args...]

So it should be something like

javac -cp gson.jar myProgram.java

Same goes for the java command.

Answer 2

Include the present directory location of myProgram or compiled java class. So run;

java -cp gson.jar:. myProgram

The dot assumes you are running myProgram from the same dir location it is place. Else use "full path to myProgram". Aleksander Stojadinovic is also right, the order of things matters with the java runtime environment!