Finding unused jars used in an eclipse project

ClassPathHelper is a good start.

It automatically identifies orphan jars and much more.

The only limitation is with dependencies that are not defined in classes, e.g. in dependency injection framework configuration files.

You also have other options/complements, such as:

• workingfrog "Relief", which relies on the ability to deal with real objects by examining their shape, size or relative place in space it gives a "physical" view on java packages, types and fields and their relationships, making them easier to handle.
• Unnecessary Code Detector: a eclipse PlugIn tool to find unnecessary (dead) public java code.

You can use one of this plugins: UCDetector or Classpath Helper

In the Maven and Gradle projects you can use those plugins to identify unused dependencies.

• For Maven : link

Use this in the pom.xml file plugin.

<build>
<plugins>
    <plugin>
        <artifactId>maven-dependency-plugin</artifactId>
        <version>3.1.2</version>
    </plugin>
</plugins>
</build>

this will give as output. In this case we add commons-collections dependency to pom.xml, but do not use in the code.

• For Gradle : link

Use this in the build.gradle file plugin.

plugins {
  id "ca.cutterslade.analyze" version "1.7.1"
}

Using legacy plugin application:

this will give as output. In this case we add dependencies unusedDeclaredArtifacts to gradlefile, but do not use in the code.