Check if characters are digits for EAN_13, EAN_8, ITF and UPC_EAN_EXTENSION (#1039)

* Check if characters are digits

* Use regex to check if input is valid. Added tests

* Create checkNumeric method

* Remove unused locals, moved attributes to top of class.

* Simplify testcase

* Reduce repeated code

* Fixed indentation

core/src/main/java/com/google/zxing/oned/EAN13Writer.java

@@ -78,6 +78,7 @@ public final class EAN13Writer extends UPCEANWriter {
             "Requested contents should be 12 or 13 digits long, but got " + length);
     }
 
+    checkNumeric(contents);
 
     int firstDigit = Character.digit(contents.charAt(0), 10);
     int parities = EAN13Reader.FIRST_DIGIT_ENCODINGS[firstDigit];

core/src/main/java/com/google/zxing/oned/EAN8Writer.java

@@ -82,6 +82,8 @@ public final class EAN8Writer extends UPCEANWriter {
             "Requested contents should be 8 digits long, but got " + length);
     }
 
+    checkNumeric(contents);
+
     boolean[] result = new boolean[CODE_WIDTH];
     int pos = 0;
 

core/src/main/java/com/google/zxing/oned/ITFWriter.java

@@ -74,6 +74,9 @@ public final class ITFWriter extends OneDimensionalCodeWriter {
       throw new IllegalArgumentException(
           "Requested contents should be less than 80 digits long, but got " + length);
     }
+
+    checkNumeric(contents);
+
     boolean[] result = new boolean[9 + 9 * length];
     int pos = appendPattern(result, 0, START_PATTERN, true);
     for (int i = 0; i < length; i += 2) {

core/src/main/java/com/google/zxing/oned/OneDimensionalCodeWriter.java

@@ -23,6 +23,7 @@ import com.google.zxing.WriterException;
 import com.google.zxing.common.BitMatrix;
 
 import java.util.Map;
+import java.util.regex.Pattern;
 
 /**
  * <p>Encapsulates functionality and implementation that is common to one-dimensional barcodes.</p>
@@ -30,6 +31,7 @@ import java.util.Map;
  * @author dsbnatut@gmail.com (Kazuki Nishiura)
  */
 public abstract class OneDimensionalCodeWriter implements Writer {
+  private static final Pattern NUMERIC = Pattern.compile("[0-9]+");
 
   @Override
   public final BitMatrix encode(String contents, BarcodeFormat format, int width, int height)
@@ -90,6 +92,14 @@ public abstract class OneDimensionalCodeWriter implements Writer {
     return output;
   }
 
+  /**
+   * Throw IllegalArgumentException if input contains characters other than digits 0-9.
+   */
+  protected static final void checkNumeric(String contents) throws IllegalArgumentException {
+    if (!NUMERIC.matcher(contents).matches()) {
+      throw new IllegalArgumentException("Input should only contain digits 0-9");
+    }
+  }
 
   /**
    * @param target encode black/white pattern into this array

core/src/main/java/com/google/zxing/oned/UPCEWriter.java

@@ -76,6 +76,8 @@ public final class UPCEWriter extends UPCEANWriter {
             "Requested contents should be 8 digits long, but got " + length);
     }
 
+    checkNumeric(contents);
+
     int firstDigit = Character.digit(contents.charAt(0), 10);
     if (firstDigit != 0 && firstDigit != 1) {
       throw new IllegalArgumentException("Number system must be 0 or 1");

core/src/test/java/com/google/zxing/oned/EAN13WriterTestCase.java

@@ -42,4 +42,8 @@ public final class EAN13WriterTestCase extends Assert {
     assertEquals(testStr, BitMatrixTestCase.matrixToString(result));
   }
 
+  @Test(expected = IllegalArgumentException.class)
+  public void testEncodeIllegalCharacters() throws WriterException {
+    new EAN13Writer().encode("5901234123abc", BarcodeFormat.EAN_13, 0, 0);
+  }
 }

core/src/test/java/com/google/zxing/oned/EAN8WriterTestCase.java

@@ -42,4 +42,8 @@ public final class EAN8WriterTestCase extends Assert {
     assertEquals(testStr, BitMatrixTestCase.matrixToString(result));
   }
 
+  @Test(expected = IllegalArgumentException.class)
+  public void testEncodeIllegalCharacters() throws WriterException {
+    new EAN8Writer().encode("96385abc", BarcodeFormat.EAN_8, 0, 0);
+  }
 }

core/src/test/java/com/google/zxing/oned/ITFWriterTestCase.java

@@ -40,4 +40,9 @@ public final class ITFWriterTestCase extends Assert {
     assertEquals(expected, BitMatrixTestCase.matrixToString(result));
   }
 
+  @Test(expected = IllegalArgumentException.class)
+  public void testEncodeIllegalCharacters() throws WriterException {
+    new ITFWriter().encode("00123456789abc", BarcodeFormat.ITF, 0, 0);
+  }
+
 }

core/src/test/java/com/google/zxing/oned/UPCEWriterTestCase.java

@@ -51,4 +51,8 @@ public final class UPCEWriterTestCase extends Assert {
     assertEquals(encoding, BitMatrixTestCase.matrixToString(result));
   }
 
+  @Test(expected = IllegalArgumentException.class)
+  public void testEncodeIllegalCharacters() throws WriterException {
+    new UPCEWriter().encode("05096abc", BarcodeFormat.UPC_E, 0, 0);
+  }
 }