src/jdk.compiler/share/classes/com/sun/tools/javac/platform/JDKPlatformProvider.java

@@ -119,11 +119,11 @@
                 for (Path section : dir) {
                     if (section.getFileName().toString().contains("-"))
                         continue;
                     for (char ver : section.getFileName().toString().toCharArray()) {
                         String verString = Character.toString(ver);
-                        Target t = Target.lookup("" + Integer.parseInt(verString, 16));
+                        Target t = Target.lookup("" + Integer.parseInt(verString, Character.MAX_RADIX));
 
                         if (t != null) {
                             SUPPORTED_JAVA_PLATFORM_VERSIONS.add(targetNumericVersion(t));
                         }
                     }

@@ -144,11 +144,11 @@
         private final String ctSymVersion;
 
         PlatformDescriptionImpl(String sourceVersion) {
             this.sourceVersion = sourceVersion;
             this.ctSymVersion =
-                    StringUtils.toUpperCase(Integer.toHexString(Integer.parseInt(sourceVersion)));
+                    StringUtils.toUpperCase(Integer.toString(Integer.parseInt(sourceVersion), Character.MAX_RADIX));
         }
 
         @Override
         public JavaFileManager getFileManager() {
             Context context = new Context();