leverage null pointer handling,

exception classes can be built using null arguments arrays which
are automatically converted to zero-sized arrays to prevent null pointer exceptions

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/branches/MATH_2_0@712142 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/math/ConvergenceException.java

@@ -31,7 +31,7 @@ public class ConvergenceException extends MathException {
      * Default constructor.
      */
     public ConvergenceException() {
-        super("Convergence failed", new Object[0]);
+        super("Convergence failed", null);
     }
     
     /**

src/java/org/apache/commons/math/geometry/CardanEulerSingularityException.java

@@ -35,7 +35,7 @@ public class CardanEulerSingularityException
    * if false it is related to EulerAngles
    */
   public CardanEulerSingularityException(boolean isCardan) {
-    super(isCardan ? "Cardan angles singularity" : "Euler angles singularity", new Object[0]);
+    super(isCardan ? "Cardan angles singularity" : "Euler angles singularity", null);
   }
 
   /** Serializable version identifier */

src/java/org/apache/commons/math/linear/RankDeficientMatrixException.java

@@ -31,7 +31,7 @@ public class RankDeficientMatrixException extends InvalidMatrixException {
      * Construct an exception with a default message.
      */
     public RankDeficientMatrixException() {
-        super("matrix is rank-deficient", new Object[0]);
+        super("matrix is rank-deficient", null);
     }
 
 }

src/java/org/apache/commons/math/linear/SingularMatrixException.java

@@ -31,7 +31,7 @@ public class SingularMatrixException extends InvalidMatrixException {
      * Construct an exception with a default message.
      */
     public SingularMatrixException() {
-        super("matrix is singular", new Object[0]);
+        super("matrix is singular", null);
     }
 
 }

src/java/org/apache/commons/math/random/NotPositiveDefiniteMatrixException.java

@@ -36,7 +36,7 @@ public class NotPositiveDefiniteMatrixException extends MathException {
      * build an exception with a default message.
      */
     public NotPositiveDefiniteMatrixException() {
-        super("not positive definite matrix", new Object[0]);
+        super("not positive definite matrix", null);
     }
 
 }

src/test/org/apache/commons/math/MathConfigurationExceptionTest.java

@@ -30,7 +30,7 @@ public class MathConfigurationExceptionTest extends TestCase {
         MathConfigurationException ex = new MathConfigurationException();
         assertNull(ex.getCause());
         assertNull(ex.getMessage());
-        assertNull(ex.getMessage(Locale.FRENCH));
+        assertEquals(0, ex.getMessage(Locale.FRENCH).length());
     }
     
     public void testConstructorPatternArguments(){

src/test/org/apache/commons/math/MathExceptionTest.java

@@ -33,7 +33,7 @@ public class MathExceptionTest extends TestCase {
         MathException ex = new MathException();
         assertNull(ex.getCause());
         assertNull(ex.getMessage());
-        assertNull(ex.getMessage(Locale.FRENCH));
+        assertEquals(0, ex.getMessage(Locale.FRENCH).length());
     }
     
     public void testConstructorPatternArguments(){
@@ -79,8 +79,8 @@ public class MathExceptionTest extends TestCase {
     public void testPrintStackTrace() {
         String outMsg = "outer message";
         String inMsg = "inner message";
-        MathException cause = new MathConfigurationException(inMsg, new Object[0]);
-        MathException ex = new MathException(outMsg, new Object[0], cause);
+        MathException cause = new MathConfigurationException(inMsg, null);
+        MathException ex = new MathException(outMsg, null, cause);
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         PrintStream ps = new PrintStream(baos);
         ex.printStackTrace(ps);
@@ -104,8 +104,8 @@ public class MathExceptionTest extends TestCase {
     public void testSerialization() {
         String outMsg = "outer message";
         String inMsg = "inner message";
-        MathException cause = new MathConfigurationException(inMsg, new Object[0]);
-        MathException ex = new MathException(outMsg, new Object[0], cause);
+        MathException cause = new MathConfigurationException(inMsg, null);
+        MathException ex = new MathException(outMsg, null, cause);
         MathException image = (MathException) TestUtils.serializeAndRecover(ex);
         
         ByteArrayOutputStream baos = new ByteArrayOutputStream();

src/test/org/apache/commons/math/linear/InvalidMatrixExceptionTest.java

@@ -29,7 +29,7 @@ public class InvalidMatrixExceptionTest extends TestCase {
      */
     public void testConstructorMessage(){
         String msg = "message";
-        InvalidMatrixException ex = new InvalidMatrixException(msg, new Object[0]);
+        InvalidMatrixException ex = new InvalidMatrixException(msg, null);
         assertEquals(msg, ex.getMessage());
     }
 }

src/test/org/apache/commons/math/linear/MatrixIndexExceptionTest.java

@@ -29,7 +29,7 @@ public class MatrixIndexExceptionTest extends TestCase {
      */
     public void testConstructorMessage(){
         String msg = "message";
-        MatrixIndexException ex = new MatrixIndexException(msg, new Object[0]);
+        MatrixIndexException ex = new MatrixIndexException(msg, null);
         assertEquals(msg, ex.getMessage());
     }
 }

src/test/org/apache/commons/math/linear/RealMatrixImplTest.java

@@ -659,7 +659,7 @@ public final class RealMatrixImplTest extends TestCase {
         if (!lu.isSquare() || lowerData.length != lowerData[0].length || upperData.length != upperData[0].length ||
                 lowerData.length != upperData.length
                 || lowerData.length != lu.getRowDimension()) {
-            throw new InvalidMatrixException("incorrect dimensions", new Object[0]);
+            throw new InvalidMatrixException("incorrect dimensions", null);
         }    
         int n = lu.getRowDimension();
         for (int i = 0; i < n; i++) {