How to compile and run kotlin program in command line with external java library

Question

I am trying kotlin for the first time.

I was able to run compile the hello world program in kotlin on command line but I am not able to compile program where I want to include external java library

import com.google.gson.Gson

data class Person(val name: String, val age: Int, val gender: String?)

fun main(args: Array<String>) {
    println("Hello world");
    val gson = Gson()
    val person = Person("navin", 30, null)
    val personJson = gson.toJson(person)
    println(personJson)
}

Directory structure

➜  kotlin tree
.
├── gson.jar
├── json.jar
└── json.kt

0 directories, 3 files
➜  kotlin

Code compilation works fine but I am not able to run the program

➜  kotlin kotlinc -classpath gson.jar json.kt -include-runtime -d json.jar
➜  kotlin java -jar json.jar -cp gson.jar                                 
Hello world
Exception in thread "main" java.lang.NoClassDefFoundError: com/google/gson/Gson
        at JsonKt.main(json.kt:7)
Caused by: java.lang.ClassNotFoundException: com.google.gson.Gson
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        ... 1 more
➜  kotlin

Need help understanding how to run the above program.

Try putting the `-jar json.jar` last when running your jar file — Minn, Dec 02 '18 at 16:41

score 4 · Accepted Answer · answered Dec 03 '18 at 12:10

4

When you use -jar, the -cp argument is ignored, so you can't specify any additional dependencies. Instead, you need to specify both jars in the -cp argument:

java -cp json.jar:gson.jar JsonKt

answered Dec 03 '18 at 12:10

yole

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score 0 · Answer 2 · answered Nov 07 '22 at 19:36

to run from command line, Kotlin program which is using external library for compile :

kotlinc -cp "C:\Users\<user>\Desktop\kotlin\programs\gson-2.10.jar" GsonTest.kt

for run:

kotlin -cp ".;C:\Users\<user>\Desktop\kotlin\programs\gson-2.10.jar" GsonTestKt

note: please give full path location for external jar's as mention above, user will be your system name.

How to compile and run kotlin program in command line with external java library

2 Answers2

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