src/share/classes/java/lang/Integer.java

rev 6518 : 8007398: Peformance improvements to Integer and Long string formatting.
Contributed-by: Steven Schlansker <stevenschlansker@gmail.com>

*** 24,34 ****
   */
  
  package java.lang;
  
  import java.lang.annotation.Native;
- import java.util.Properties;
  
  /**
   * The {@code Integer} class wraps a value of the primitive type
   * {@code int} in an object. An object of type {@code Integer}
   * contains a single field whose type is {@code int}.
--- 24,33 ----
*** 183,193 ****
       * @return  an unsigned string representation of the argument in the specified radix.
       * @see     #toString(int, int)
       * @since 1.8
       */
      public static String toUnsignedString(int i, int radix) {
!         return Long.toString(toUnsignedLong(i), radix);
      }
  
      /**
       * Returns a string representation of the integer argument as an
       * unsigned integer in base 16.
--- 182,192 ----
       * @return  an unsigned string representation of the argument in the specified radix.
       * @see     #toString(int, int)
       * @since 1.8
       */
      public static String toUnsignedString(int i, int radix) {
!         return Long.toUnsignedString(toUnsignedLong(i), radix);
      }
  
      /**
       * Returns a string representation of the integer argument as an
       * unsigned integer in base 16.
*** 306,325 ****
  
      /**
       * Convert the integer to an unsigned number.
       */
      private static String toUnsignedString0(int i, int shift) {
!         char[] buf = new char[32];
!         int charPos = 32;
          int radix = 1 << shift;
          int mask = radix - 1;
          do {
              buf[--charPos] = digits[i & mask];
              i >>>= shift;
          } while (i != 0);
  
!         return new String(buf, charPos, (32 - charPos));
      }
  
  
      final static char [] DigitTens = {
          '0', '0', '0', '0', '0', '0', '0', '0', '0', '0',
--- 305,328 ----
  
      /**
       * Convert the integer to an unsigned number.
       */
      private static String toUnsignedString0(int i, int shift) {
!         // assert shift > 0 && shift <=5 : "Illegal shift value";
!         int mag = Integer.SIZE - Integer.numberOfLeadingZeros(i);
!         int chars = Math.max(((mag + (shift - 1)) / shift), 1);
!         char[] buf = new char[chars];
!         int charPos = chars;
          int radix = 1 << shift;
          int mask = radix - 1;
          do {
              buf[--charPos] = digits[i & mask];
              i >>>= shift;
          } while (i != 0);
  
!         // Use special constructor which takes over "buf".
!         return new String(buf, true);
      }
  
  
      final static char [] DigitTens = {
          '0', '0', '0', '0', '0', '0', '0', '0', '0', '0',
*** 873,882 ****
--- 876,886 ----
  
      /**
       * Returns the value of this {@code Integer} as a {@code long}
       * after a widening primitive conversion.
       * @jls 5.1.2 Widening Primitive Conversions
+      * @see Integer#toUnsignedLong(int)
       */
      public long longValue() {
          return (long)value;
      }