# 3rd party Java Lib: ImportError **URL:** \ **Category:** Ignition\ **Tags:** scripting, ignition81\ **Created:** [February 26, 2025, 11:50am UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897 "2025-02-26T11:50:49Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Stef\_Van\_Poucke](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@Stef\_Van\_Poucke](https://forum.inductiveautomation.com/u/Stef_Van_Poucke)\ **Post date:** [February 26, 2025, 11:50am UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897/1 "2025-02-26T11:50:49Z")
I would like to use a 3rd party Java Lib in scripting: [GitHub - auth0/java-jwt: Java implementation of JSON Web Token (JWT)](https://github.com/auth0/java-jwt) I've found a jar file: [Download java-jwt.jar - @com.auth0](https://mavenlibs.com/jar/file/com.auth0/java-jwt) and I've put it in the ignition/lib/core/common folder, gateway is restarted. I'm trying to start testing functionality: from com.auth0.jwt import \* But I get this error: ImportError: No module named auth0 I know the proper way is to create an ignition module but we're not that familiar with java and never did such a thing so for now I just want to get something working and then look at a more permanent/better solution. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [February 26, 2025, 12:03pm UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897/2 "2025-02-26T12:03:16Z")
If you’re running this in the Designer script console you do also need to restart the Designer before it will load that JAR file. ---
**Author:** ![Stef\_Van\_Poucke](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@Stef\_Van\_Poucke](https://forum.inductiveautomation.com/u/Stef_Van_Poucke)\ **Post date:** [February 26, 2025, 12:13pm UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897/3 "2025-02-26T12:13:57Z")
Just restarted Gateway & Designer again but no change: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/c/2/c2d2b892a649c495dda463f65283685eef3641fb.png) ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [February 26, 2025, 12:20pm UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897/4 "2025-02-26T12:20:41Z")
Hmm, this library has other transitive dependencies you probably haven't included in lib/core/common, so I bet it's failing to load somewhere. > ---
**Author:** ![Stef\_Van\_Poucke](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@Stef\_Van\_Poucke](https://forum.inductiveautomation.com/u/Stef_Van_Poucke)\ **Post date:** [February 26, 2025, 12:42pm UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897/5 "2025-02-26T12:42:58Z")
How would I best go about troubleshooting this? Ive added these: [Download jackson-core.jar - @com.fasterxml.jackson.core](https://mavenlibs.com/jar/file/com.fasterxml.jackson.core/jackson-core) [Download jackson-databind.jar - @com.fasterxml.jackson.core](https://mavenlibs.com/jar/file/com.fasterxml.jackson.core/jackson-databind) and rebooted gateway/designer and I'm still getting the same result. If there's another JWT Lib that you know works would also be helpfull. All I need is to verify a JWT, so validate signature and decode the base 64 to check scope and expiry I might be able to do the same with a crypto and base 64 lib ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [February 26, 2025, 12:54pm UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897/6 "2025-02-26T12:54:51Z")
In addition to the above, you should know that jython cannot use `*` in imports from java packages or classes. You must import specific classes. It isn't a syntax error, but just doesn't yield anything. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [February 26, 2025, 1:24pm UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897/7 "2025-02-26T13:24:12Z")
I think you also need jackson-annotations-2.15.4.jar. I just gave this a try and it worked for me 🤷‍♂️ Added these 4 JAR files to lib/core/common, restarted Gateway, launched new Designer: ```python kevin@DV-55J5DY3-LT ~/D/m/t/dependency> ls -lh total 2.3M -rw-r--r--. 1 kevin kevin 74K Feb 15 2024 jackson-annotations-2.15.4.jar -rw-r--r--. 1 kevin kevin 536K Feb 15 2024 jackson-core-2.15.4.jar -rw-r--r--. 1 kevin kevin 1.6M Feb 15 2024 jackson-databind-2.15.4.jar -rw-r--r--. 1 kevin kevin 63K Jan 29 06:39 java-jwt-4.5.0.jar ``` In the script console: ```python from com.auth0.jwt import JWT JWT.decode("") ``` (which obviously errors out, but shows the library is loaded) ```python Java Traceback: Traceback (most recent call last): File "", line 3, in at com.auth0.jwt.TokenUtils.wrongNumberOfParts(TokenUtils.java:45) at com.auth0.jwt.TokenUtils.splitToken(TokenUtils.java:23) at com.auth0.jwt.JWTDecoder.(JWTDecoder.java:37) at com.auth0.jwt.JWTDecoder.(JWTDecoder.java:33) at com.auth0.jwt.JWT.decode(JWT.java:52) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.base/java.lang.reflect.Method.invoke(Unknown Source) com.auth0.jwt.exceptions.JWTDecodeException: com.auth0.jwt.exceptions.JWTDecodeException: The token was expected to have 3 parts, but got 0. at org.python.core.Py.JavaError(Py.java:545) at org.python.core.Py.JavaError(Py.java:536) at org.python.core.PyReflectedFunction. __call__ (PyReflectedFunction.java:192) at org.python.core.PyReflectedFunction. __call__ (PyReflectedFunction.java:208) at org.python.core.PyObject. __call__ (PyObject.java:461) at org.python.core.PyObject. __call__ (PyObject.java:465) at org.python.pycode._pyx11.f$0(:3) at org.python.pycode._pyx11.call_function() at org.python.core.PyTableCode.call(PyTableCode.java:173) at org.python.core.PyCode.call(PyCode.java:18) at org.python.core.Py.runCode(Py.java:1703) at org.python.core.Py.exec(Py.java:1747) at org.python.util.PythonInterpreter.exec(PythonInterpreter.java:277) at org.python.util.InteractiveInterpreter.runcode(InteractiveInterpreter.java:130) at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:628) at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:616) at java.desktop/javax.swing.SwingWorker$1.call(Unknown Source) at java.base/java.util.concurrent.FutureTask.run(Unknown Source) at java.desktop/javax.swing.SwingWorker.run(Unknown Source) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.base/java.lang.Thread.run(Unknown Source) Caused by: com.auth0.jwt.exceptions.JWTDecodeException: The token was expected to have 3 parts, but got 0. at com.auth0.jwt.TokenUtils.wrongNumberOfParts(TokenUtils.java:45) at com.auth0.jwt.TokenUtils.splitToken(TokenUtils.java:23) at com.auth0.jwt.JWTDecoder.(JWTDecoder.java:37) at com.auth0.jwt.JWTDecoder.(JWTDecoder.java:33) at com.auth0.jwt.JWT.decode(JWT.java:52) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.base/java.lang.reflect.Method.invoke(Unknown Source) at org.python.core.PyReflectedFunction. __call__ (PyReflectedFunction.java:190) ... 19 more Traceback (most recent call last): File "", line 3, in at com.auth0.jwt.TokenUtils.wrongNumberOfParts(TokenUtils.java:45) at com.auth0.jwt.TokenUtils.splitToken(TokenUtils.java:23) at com.auth0.jwt.JWTDecoder.(JWTDecoder.java:37) at com.auth0.jwt.JWTDecoder.(JWTDecoder.java:33) at com.auth0.jwt.JWT.decode(JWT.java:52) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.base/java.lang.reflect.Method.invoke(Unknown Source) com.auth0.jwt.exceptions.JWTDecodeException: com.auth0.jwt.exceptions.JWTDecodeException: The token was expected to have 3 parts, but got 0. >>> ``` ---
**Author:** ![Stef\_Van\_Poucke](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@Stef\_Van\_Poucke](https://forum.inductiveautomation.com/u/Stef_Van_Poucke)\ **Post date:** [February 26, 2025, 1:39pm UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897/8 "2025-02-26T13:39:45Z")
Great! thx. This also works on my end. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [February 26, 2025, 1:40pm UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897/9 "2025-02-26T13:40:39Z")
Just keep in mind you'll have to repeat this procedure any time you upgrade Ignition. These lib/core/\* directories are wiped out and replaced during the upgrade. ---
**Author:** ![Stef\_Van\_Poucke](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@Stef\_Van\_Poucke](https://forum.inductiveautomation.com/u/Stef_Van_Poucke)\ **Post date:** [February 26, 2025, 1:54pm UTC](https://forum.inductiveautomation.com/t/3rd-party-java-lib-importerror/102897/10 "2025-02-26T13:54:53Z")
Thanks for the headsup. When life is less busy we'll look into creating a .modl or even better, ignition just implements JWT verify and JWT decode 😃