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

*** 410,420 ****
  
      @Override
      @HotSpotIntrinsicCandidate
      public String toString() {
          // Create a copy, don't share the array
!         return new String(value, 0, count);
      }
  
      /**
       * Save the state of the {@code StringBuilder} instance to a stream
       * (that is, serialize it).
--- 410,421 ----
  
      @Override
      @HotSpotIntrinsicCandidate
      public String toString() {
          // Create a copy, don't share the array
!         return isLatin1() ? StringLatin1.newString(value, 0, count)
!                           : StringUTF16.newStringSB(value, 0, count);
      }
  
      /**
       * Save the state of the {@code StringBuilder} instance to a stream
       * (that is, serialize it).
*** 428,447 ****
       */
      private void writeObject(java.io.ObjectOutputStream s)
          throws java.io.IOException {
          s.defaultWriteObject();
          s.writeInt(count);
!         s.writeObject(value);
      }
  
      /**
       * readObject is called to restore the state of the StringBuffer from
       * a stream.
       */
      private void readObject(java.io.ObjectInputStream s)
          throws java.io.IOException, ClassNotFoundException {
          s.defaultReadObject();
          count = s.readInt();
!         value = (char[]) s.readObject();
      }
  
  }
--- 429,455 ----
       */
      private void writeObject(java.io.ObjectOutputStream s)
          throws java.io.IOException {
          s.defaultWriteObject();
          s.writeInt(count);
!         char[] val = new char[capacity()];
!         if (isLatin1()) {
!             StringLatin1.getChars(value, 0, count, val, 0);
!         } else {
!             StringUTF16.getChars(value, 0, count, val, 0);
!         }
!         s.writeObject(val);
      }
  
      /**
       * readObject is called to restore the state of the StringBuffer from
       * a stream.
       */
      private void readObject(java.io.ObjectInputStream s)
          throws java.io.IOException, ClassNotFoundException {
          s.defaultReadObject();
          count = s.readInt();
!         char[] val = (char[]) s.readObject();
!         initBytes(val, 0, val.length);
      }
  
  }