optimize parseInt for <img> tag attribute parsing

Performance better as using Numberformat.parse or parseInt(substring())

source/net/yacy/cora/util/NumberTools.java

@@ -27,7 +27,8 @@ public class NumberTools {
 
     /**
      * this method replaces Long.parseLong/2 where a substring of decimal numbers shall be parsed
-     * Strings are also auto-trimmed, that means parsing stops at spaces without throwing a NumberFormatException
+     * Strings are also auto-trimmed, that means parsing stops at trailing spaces without throwing a NumberFormatException
+     * leading spaces are skip'd and parse stops at first none digit character
      * @param s
      * @param startPos
      * @return the number
@@ -54,6 +55,7 @@ public class NumberTools {
         int digit;
         char c;
 
+        while (s.charAt(i) == ' ') i++; // skip leading blanks
         char firstChar = s.charAt(i);
         if (firstChar < '0') {
             if (firstChar == '-') {
@@ -66,7 +68,7 @@ public class NumberTools {
         multmin = limit / 10;
         while (i < endPos) {
             c = s.charAt(i++);
-            if (c == ' ') break;
+            if (c < '0' || c > '9') break; // stop at first non digit character
             digit = c - '0';
             if (digit < 0 || digit > 9 || result < multmin) throw new NumberFormatException(s);
             result *= 10;
@@ -97,6 +99,7 @@ public class NumberTools {
         int digit;
         char c;
 
+        while (s.charAt(i) == ' ') i++; // skip leading blanks
         char firstChar = s.charAt(i);
         if (firstChar < '0') {
             if (firstChar == '-') {
@@ -109,7 +112,7 @@ public class NumberTools {
         multmin = limit / 10;
         while (i < endPos) {
             c = s.charAt(i++);
-            if (c == ' ') break;
+            if (c < '0' || c > '9') break; // stop at first non digit character
             digit = c - '0';
             if (digit < 0  || digit > 9 || result < multmin) throw new NumberFormatException(s);
             result *= 10;

source/net/yacy/document/parser/html/ContentScraper.java

@@ -28,7 +28,6 @@ import java.io.Writer;
 import java.lang.reflect.Array;
 import java.net.MalformedURLException;
 import java.nio.charset.Charset;
-import java.text.NumberFormat;
 import java.text.ParseException;
 import java.util.ArrayList;
 import java.util.Date;
@@ -415,15 +414,14 @@ public class ContentScraper extends AbstractScraper implements Scraper {
                 if (src.length() > 0) {
                     final DigestURL url = absolutePath(src);
                     if (url != null) {
-                        // use Numberformat.parse to allow parse of "550px"
-                        NumberFormat intnum = NumberFormat.getIntegerInstance ();
-                        final int width = intnum.parse(tag.opts.getProperty("width", "-1")).intValue(); // Integer.parseInt fails on "200px"
-                        final int height = intnum.parse(tag.opts.getProperty("height", "-1")).intValue();
+                        // use to allow parse of "550px", with better performance as Numberformat.parse
+                        final int width = NumberTools.parseIntDecSubstring(tag.opts.getProperty("width", "-1")); // Integer.parseInt fails on "200px"
+                        final int height = NumberTools.parseIntDecSubstring(tag.opts.getProperty("height", "-1"));
                         final ImageEntry ie = new ImageEntry(url, tag.opts.getProperty("alt", EMPTY_STRING), width, height, -1);
                         this.images.add(ie);
                     }
                 }
-            } catch (final ParseException e) {}
+            } catch (final NumberFormatException e) {}
             this.evaluationScores.match(Element.imgpath, src);
         } else if(tag.name.equalsIgnoreCase("base")) {
             try {

test/net/yacy/cora/util/NumberToolsTest.java

@@ -0,0 +1,27 @@
+package net.yacy.cora.util;
+
+import static net.yacy.cora.util.NumberTools.parseIntDecSubstring;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class NumberToolsTest {
+
+    /**
+     * Test of parseLongDecSubstring method, of class NumberTools.
+     */
+    @Test
+    public void testParseIntDecSubstring() {
+        String[] TestNumbers = new String[]{
+            "101", " 102", " 103", " 104 ",
+            "+105", " -106", " +107 ", " -108 ",
+            "109px", " 110px"};
+
+        int i=101;
+        for (String s : TestNumbers) {
+            int result = parseIntDecSubstring(s);
+            assertEquals (s + " = " + Integer.toString(i),i,Math.abs(result));
+            i++;
+        }
+
+    }
+}