def _find_all_bootstrap_jars(self):
    def get_path(key):
      return DistributionLocator.cached().system_properties.get(key, '').split(':')

    def find_jars_in_dirs(dirs):
      ret = []
      for d in dirs:
        if os.path.isdir(d):
          ret.extend(filter(lambda s: s.endswith('.jar'), os.listdir(d)))
      return ret

    # Note: assumes HotSpot, or some JVM that supports sun.boot.class.path.
    # TODO: Support other JVMs? Not clear if there's a standard way to do so.
    # May include loose classes dirs.
    boot_classpath = get_path('sun.boot.class.path')

    # Note that per the specs, overrides and extensions must be in jars.
    # Loose class files will not be found by the JVM.
    override_jars = find_jars_in_dirs(get_path('java.endorsed.dirs'))
    extension_jars = find_jars_in_dirs(get_path('java.ext.dirs'))

    # Note that this order matters: it reflects the classloading order.
    bootstrap_jars = filter(os.path.isfile, override_jars + boot_classpath + extension_jars)
    return bootstrap_jars  # Technically, may include loose class dirs from boot_classpath.
dataset/ETHPy150Open pantsbuild/pants/src/python/pants/backend/jvm/tasks/jvm_dependency_analyzer.py/JvmDependencyAnalyzer._find_all_bootstrap_jars/original