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

rev 12069 : [mq]: 8058779-Faster-implementation-of-String-replace-SB

@@ -2245,12 +2245,32 @@
      * @param  replacement The replacement sequence of char values
      * @return  The resulting string
      * @since 1.5
      */
     public String replace(CharSequence target, CharSequence replacement) {
-        return Pattern.compile(target.toString(), Pattern.LITERAL).matcher(
-                this).replaceAll(Matcher.quoteReplacement(replacement.toString()));
+        String starget = target.toString();
+        String srepl = replacement.toString();
+        int i = 0, j = indexOf(starget);
+        if (j < 0) {
+            return this;
+        }
+        int targLen = starget.length();
+        int targLen1 = Math.max(targLen, 1);
+        final char[] value = this.value;
+        final char[] replValue = srepl.value;
+        int newLenHint = value.length - targLen + replValue.length;
+        if (newLenHint < 0) {
+            throw new OutOfMemoryError();
+        }
+        StringBuilder sb = new StringBuilder(newLenHint);
+        do {
+            sb.append(value, i, j - i)
+                .append(replValue);
+            i = j + targLen;
+        } while (j < value.length && (j = indexOf(starget, j + targLen1)) > 0);
+
+        return sb.append(value, i, value.length - i).toString();
     }
 
     /**
      * Splits this string around matches of the given
      * <a href="../util/regex/Pattern.html#sum">regular expression</a>.