src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/DefaultCompressPlugin.java

*** 123,133 ****
                      case LEVEL_2:
                          ss = new StringSharingPlugin(resFilter);
                          zip = new ZipPlugin(resFilter);
                          break;
                      default:
!                         throw new PluginException("Invalid level " + level);
                  }
              } else {
                  ss = new StringSharingPlugin(resFilter);
                  zip = new ZipPlugin(resFilter);
              }
--- 123,133 ----
                      case LEVEL_2:
                          ss = new StringSharingPlugin(resFilter);
                          zip = new ZipPlugin(resFilter);
                          break;
                      default:
!                         throw new IllegalArgumentException("Invalid compression level " + level);
                  }
              } else {
                  ss = new StringSharingPlugin(resFilter);
                  zip = new ZipPlugin(resFilter);
              }