NoClassDefFoundError appears after Java project is packaged into JAR: How to troubleshoot JDK version compatibility issues?

Java project encountered NoClassDefFoundError problem when packaged into executable JAR file

Many Java developers may encounter a headache-inducing NoClassDefFoundError exception when packaging projects into executable JAR files. This article will analyze and answer a case where NoClassDefFoundError: javax/xml/transform/e error occurs after using Gradle to package Java projects and introduce a third-party JAR package.

In the problem description, the developer ran the code in the IDEA environment correctly, but after using Gradle to package it into a JAR file, when running it through the java -jar test.jar command, NoClassDefFoundError: javax/xml/transform/e exception was thrown. The developer suspected that it was a classpath issue and provided the project's Gradle configuration file and the structure information of the third-party JAR package. The structure of the third-party JAR package shows that it contains the class file under the javax/xml/transform/e path, but the error message shows javax.xml/transform/e, which caused confusion among developers.

The key to this problem lies in the choice of the JDK version. The answer points out that the root cause of the problem lies in the use of JDK 20. In JDK 20 and later, the javax.xml.transform package has been removed, causing the code that depends on the package to not function properly. When developers run code in IDEA environment, they may use different JDK versions (such as JDK 1.8), so they run normally in IDEA. After switching to JDK version 1.8, the problem was solved because JDK 1.8 still includes the javax.xml.transform package. This shows that when building and running Java projects, it is crucial to choose a JDK version that is compatible with your project.

The above is the detailed content of NoClassDefFoundError appears after Java project is packaged into JAR: How to troubleshoot JDK version compatibility issues?. For more information, please follow other related articles on the PHP Chinese website!