jdk/src/share/classes/java/lang/String.java
changeset 3617 422105639b62
parent 2497 903fd9d785ef
child 3964 cf913644be58
--- a/jdk/src/share/classes/java/lang/String.java	Tue Aug 11 20:06:52 2009 -0600
+++ b/jdk/src/share/classes/java/lang/String.java	Thu Aug 13 10:50:23 2009 -0700
@@ -2301,6 +2301,54 @@
      * @spec JSR-51
      */
     public String[] split(String regex, int limit) {
+        /* fastpath if the regex is a
+           (1)one-char String and this character is not one of the
+              RegEx's meta characters ".$|()[{^?*+\\", or
+           (2)two-char String and the first char is the backslash and
+              the second is not the ascii digit or ascii letter.
+        */
+        char ch = 0;
+        if (((regex.count == 1 &&
+             ".$|()[{^?*+\\".indexOf(ch = regex.charAt(0)) == -1) ||
+             (regex.length() == 2 &&
+              regex.charAt(0) == '\\' &&
+              (((ch = regex.charAt(1))-'0')|('9'-ch)) < 0 &&
+              ((ch-'a')|('z'-ch)) < 0 &&
+              ((ch-'A')|('Z'-ch)) < 0)) &&
+            (ch < Character.MIN_HIGH_SURROGATE ||
+             ch > Character.MAX_LOW_SURROGATE))
+        {
+            int off = 0;
+            int next = 0;
+            boolean limited = limit > 0;
+            ArrayList<String> list = new ArrayList<String>();
+            while ((next = indexOf(ch, off)) != -1) {
+                if (!limited || list.size() < limit - 1) {
+                    list.add(substring(off, next));
+                    off = next + 1;
+                } else {    // last one
+                    //assert (list.size() == limit - 1);
+                    list.add(substring(off, count));
+                    off = count;
+                    break;
+                }
+            }
+            // If no match was found, return this
+            if (off == 0)
+                return new String[] { this };
+
+            // Add remaining segment
+            if (!limited || list.size() < limit)
+                list.add(substring(off, count));
+
+            // Construct result
+            int resultSize = list.size();
+            if (limit == 0)
+                while (resultSize > 0 && list.get(resultSize-1).length() == 0)
+                    resultSize--;
+            String[] result = new String[resultSize];
+            return list.subList(0, resultSize).toArray(result);
+        }
         return Pattern.compile(regex).split(this, limit);
     }