src/java.base/share/classes/java/lang/AbstractStringBuilder.java

*** 1,7 ****
  /*
!  * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 87,96 ****
--- 87,119 ----
              coder = UTF16;
          }
      }
  
      /**
+      * Compares the objects of two AbstractStringBuilder implementations lexicographically.
+      *
+      * @since 11
+      */
+     int compareTo(AbstractStringBuilder another) {
+         if (this == another) {
+             return 0;
+         }
+ 
+         byte val1[] = value;
+         byte val2[] = another.value;
+         int count1 = this.count;
+         int count2 = another.count;
+ 
+         if (coder == another.coder) {
+             return isLatin1() ? StringLatin1.compareTo(val1, val2, count1, count2)
+                               : StringUTF16.compareTo(val1, val2, count1, count2);
+         }
+         return isLatin1() ? StringLatin1.compareToUTF16(val1, val2, count1, count2)
+                           : StringUTF16.compareToLatin1(val1, val2, count1, count2);
+     }
+ 
+     /**
       * Returns the length (character count).
       *
       * @return  the length of the sequence of characters currently
       *          represented by this object
       */