MATH-1688: Reject malformed grouping separators in ComplexFormat

commons-math-legacy/src/main/java/org/apache/commons/math4/legacy/util/ComplexFormat.java

@@ -37,7 +37,7 @@
  */
 public class ComplexFormat {
 
-     /** The default imaginary character. */
+    /** The default imaginary character. */
     private static final String DEFAULT_IMAGINARY_CHARACTER = "i";
     /** The notation used to signify the imaginary part of the complex number. */
     private final String imaginaryCharacter;
@@ -52,7 +52,7 @@ public class ComplexFormat {
      */
     public ComplexFormat() {
         this.imaginaryCharacter = DEFAULT_IMAGINARY_CHARACTER;
-        this.imaginaryFormat = CompositeFormat.getDefaultNumberFormat();
+        this.imaginaryFormat = getDefaultNumberFormat();
         this.realFormat = imaginaryFormat;
     }
 
@@ -93,6 +93,27 @@ public ComplexFormat(NumberFormat realFormat, NumberFormat imaginaryFormat)
         this.realFormat = realFormat;
     }
 
+    /**
+     * Creates the default number format used by complex values.
+     *
+     * @return a number format that does not accept grouping separators.
+     */
+    private static NumberFormat getDefaultNumberFormat() {
+        return getDefaultNumberFormat(Locale.getDefault());
+    }
+
+    /**
+     * Creates the default number format used by complex values.
+     *
+     * @param locale the locale used by the format.
+     * @return a number format that does not accept grouping separators.
+     */
+    private static NumberFormat getDefaultNumberFormat(final Locale locale) {
+        final NumberFormat format = CompositeFormat.getDefaultNumberFormat(locale);
+        format.setGroupingUsed(false);
+        return format;
+    }
+
     /**
      * Create an instance with a custom imaginary character, and the default
      * number format for both real and imaginary parts.
@@ -104,7 +125,7 @@ public ComplexFormat(NumberFormat realFormat, NumberFormat imaginaryFormat)
      */
     public ComplexFormat(String imaginaryCharacter)
         throws NullArgumentException, NoDataException {
-        this(imaginaryCharacter, CompositeFormat.getDefaultNumberFormat());
+        this(imaginaryCharacter, getDefaultNumberFormat());
     }
 
     /**
@@ -311,7 +332,7 @@ public static ComplexFormat getInstance() {
      * @return the complex format specific to the given locale.
      */
     public static ComplexFormat getInstance(Locale locale) {
-        NumberFormat f = CompositeFormat.getDefaultNumberFormat(locale);
+        NumberFormat f = getDefaultNumberFormat(locale);
         return new ComplexFormat(f);
     }
 
@@ -327,7 +348,7 @@ public static ComplexFormat getInstance(Locale locale) {
      */
     public static ComplexFormat getInstance(String imaginaryCharacter, Locale locale)
         throws NullArgumentException, NoDataException {
-        NumberFormat f = CompositeFormat.getDefaultNumberFormat(locale);
+        NumberFormat f = getDefaultNumberFormat(locale);
         return new ComplexFormat(imaginaryCharacter, f);
     }
 

commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/util/ComplexFormatAbstractTest.java

@@ -444,4 +444,19 @@ public void testParseMissingImaginaryCharacter() {
         String invalidComplex = "3 + 5";
         format.parse(invalidComplex);
     }
+
+    // MATH-1688.
+    @Test
+    public void testParseRejectsInvalidGroupingSeparators() {
+        final ComplexFormat format = new ComplexFormat();
+        final String[] invalid = {",,7+,,,2i", ",8+,,3i", ",7", "7,,8"};
+        for (final String source : invalid) {
+            try {
+                format.parse(source);
+                Assert.fail("Expected parsing to reject: " + source);
+            } catch (MathParseException expected) {
+                // Expected.
+            }
+        }
+    }
 }