correct off-by-one mistake in RegexBasedLocationExtractionStrategy

add tests for RegexBasedLocationExtractionStrategy

DEVSIX-1816

Author: Joris Schellekens

kernel/src/main/java/com/itextpdf/kernel/pdf/canvas/parser/listener/RegexBasedLocationExtractionStrategy.java

@@ -87,7 +87,7 @@ public Collection<IPdfTextLocation> getResultantLocations() {
         Matcher mat = pattern.matcher(txt.text);
         while (mat.find()) {
             int startIndex = txt.indexMap.get(mat.start());
-            int endIndex = txt.indexMap.get(mat.end());
+            int endIndex = txt.indexMap.get(mat.end() - 1);
             for (Rectangle r : toRectangles(parseResult.subList(startIndex, endIndex))) {
                 retval.add(new DefaultPdfTextLocation(0, r, mat.group(0)));
             }

kernel/src/test/java/com/itextpdf/kernel/pdf/canvas/parser/listener/RegexBasedLocationExtractionStrategyTest.java

@@ -0,0 +1,56 @@
+package com.itextpdf.kernel.pdf.canvas.parser.listener;
+
+import com.itextpdf.kernel.pdf.PdfDocument;
+import com.itextpdf.kernel.pdf.PdfReader;
+import com.itextpdf.kernel.pdf.canvas.parser.PdfCanvasProcessor;
+import com.itextpdf.test.ExtendedITextTest;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+import java.util.regex.Pattern;
+
+public class RegexBasedLocationExtractionStrategyTest extends ExtendedITextTest {
+
+    private static final String sourceFolder = "./src/test/resources/com/itextpdf/kernel/parser/RegexBasedLocationExtractionStrategyTest/";
+
+    @Test
+    public void test01() throws IOException {
+        System.out.println(new File(sourceFolder).getAbsolutePath());
+
+        PdfDocument pdfDocument = new PdfDocument(new PdfReader(sourceFolder + "in01.pdf"));
+
+        // build strategy
+        RegexBasedLocationExtractionStrategy extractionStrategy = new RegexBasedLocationExtractionStrategy(Pattern.compile("\\{\\{Signature\\}\\}"));
+
+        // get locations
+        List<IPdfTextLocation> locationList = new ArrayList<>();
+        for (int x = 1; x <= pdfDocument.getNumberOfPages(); x++) {
+            new PdfCanvasProcessor(extractionStrategy).processPageContent(pdfDocument.getPage(x));
+            for(IPdfTextLocation location : extractionStrategy.getResultantLocations()) {
+                if(location != null) {
+                    locationList.add(location);
+                }
+            }
+        }
+
+        // compare
+        Assert.assertEquals(locationList.size(), 1);
+
+        IPdfTextLocation loc = locationList.get(0);
+
+        Assert.assertEquals(loc.getText(), "{{Signature}}");
+        Assert.assertEquals(23, (int) loc.getRectangle().getX());
+        Assert.assertEquals(375, (int) loc.getRectangle().getY());
+        Assert.assertEquals(52, (int) loc.getRectangle().getWidth());
+        Assert.assertEquals(11, (int) loc.getRectangle().getHeight());
+
+        // close
+        pdfDocument.close();
+    }
+}