Module org.elasticsearch.base
Package org.elasticsearch.jdk

Class JarHell

java.lang.Object
org.elasticsearch.jdk.JarHell
public class JarHell extends Object
Simple check for duplicate class files across the classpath.

This class checks for incompatibilities in the following ways:

  • Checks that class files are not duplicated across jars.
  • Checks any X-Compile-Target-JDK value in the jar manifest is compatible with current JRE
  • Checks any X-Compile-Elasticsearch-Version value in the jar manifest is compatible with the current ES

  • Method Details

    • main

      public static void main(String[] args) throws Exception
      Simple driver class, can be used eg. from builds. Returns non-zero on jar-hell
      Throws:
      Exception

    • checkJarHell

      public static void checkJarHell(Consumer<String> output) throws IOException, URISyntaxException
      Checks the current classpath for duplicate classes
      Parameters:
      output - A String Consumer to which debug output will be sent
      Throws:
      IllegalStateException - if jar hell was found
      IOException
      URISyntaxException

    • parseClassPath

      public static Set<URL> parseClassPath()
      Parses the classpath into an array of URLs
      Returns:
      array of URLs
      Throws:
      IllegalStateException - if the classpath contains empty elements

    • parseModulesAndClassPath

      public static Set<URL> parseModulesAndClassPath()
      Returns a set of URLs that contain artifacts from both the non-JDK boot modules and class path. These URLs constitute the loadable application artifacts in the system class loader.

    • checkJarHell

      public static void checkJarHell(Set<URL> urls, Consumer<String> output) throws URISyntaxException, IOException
      Checks the set of URLs for duplicate classes
      Parameters:
      urls - A set of URLs from the system class loader to be checked for conflicting jars
      output - A String Consumer to which debug output will be sent
      Throws:
      IllegalStateException - if jar hell was found
      URISyntaxException
      IOException

    • checkJavaVersion

      public static void checkJavaVersion(String resource, String targetVersion)
      Checks that the java specification version targetVersion required by resource is compatible with the current installation.