How to Resolve Maven JAR Dependency Conflicts

When using Maven, developers may encounter JAR package conflicts where multiple dependencies contain the same JAR, leading to compilation or runtime errors.

Solution 1: Maven Exclusions – Exclude transitive dependencies directly in the <dependency> declaration to prevent the conflicting JAR from being included.

Solution 2: Maven Scope – Use the scope attribute (compile, test, provided, runtime, system, import) to limit where a dependency is applied, controlling which JARs are loaded during compilation, testing, or execution.

While these two methods often fix compile‑time issues, they may still cause class‑not‑found errors at runtime.

Solution 3: Maven Shade Plugin Relocation – Relocate (rename) classes from third‑party JARs using the shade plugin, bundling them into the final artifact under a different package name, as done by projects like Apache Flink for Guava, Netty, and Jackson.

This approach is practical but may not resolve conflicts between multiple third‑party dependencies.

Solution 4: Class Isolation Strategies – Implement class‑loader isolation mechanisms (e.g., Apache Flink, Ant Financial’s SOFAArk, Tomcat) to separate conflicting classes at runtime.

Conclusion – When facing Maven JAR conflicts, choose the appropriate method based on the specific scenario: exclusions for simple cases, scope to limit usage, shade plugin for class relocation, or class‑loader isolation for complex runtime conflicts.