REFACTORING, mainly extracting multiple try catch blocks to get the code more Readable.

src/main/java/com/ugsbo/matrixcalc/MatrixCalcController.java

@@ -15,6 +15,9 @@ public class MatrixCalcController {
     @FXML
     private TextArea matrixATextArea, matrixBTextArea;
 
+    private MatrixCalcMath math = new MatrixCalcMath();
+    private MatrixCalcIOUtils util = new MatrixCalcIOUtils();
+
     /**
      * Konstructor is called before initialize()
      */
@@ -32,16 +35,11 @@ public class MatrixCalcController {
          * Convert Strings to matricies, multiply them and output the result.
          */
         multiplyButton.setOnMouseClicked((event) -> {
-            MatrixCalcMath math = new MatrixCalcMath();
-            MatrixCalcIOUtils util = new MatrixCalcIOUtils();
-
             String stringMatrixA = matrixATextArea.getText();
             String stringMatrixB = matrixBTextArea.getText();
-            try {
+            String[] stringMatrix = { stringMatrixA, stringMatrixB };
 
-            } catch (Exception e) {
-                //TODO: handle exception
-            }
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 2);
 
             double[][] matrixA = util.stringToMatrix(stringMatrixA);
             double[][] matrixB = util.stringToMatrix(stringMatrixB);
@@ -55,15 +53,10 @@ public class MatrixCalcController {
         });
 
         transposeButton.setOnMouseClicked((event) -> {
-            MatrixCalcMath math = new MatrixCalcMath();
-            MatrixCalcIOUtils util = new MatrixCalcIOUtils();
-
             String stringMatrixA = matrixATextArea.getText();
-            try {
+            String[] stringMatrix = { stringMatrixA, "" };
 
-            } catch (Exception e) {
-                //TODO: handle exception
-            }
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 1);
 
             double[][] matrixA = util.stringToMatrix(stringMatrixA);
             double[][] result = math.matrixTransponation(matrixA);
@@ -75,16 +68,11 @@ public class MatrixCalcController {
         });
 
         addButton.setOnMouseClicked((event) -> {
-            MatrixCalcMath math = new MatrixCalcMath();
-            MatrixCalcIOUtils util = new MatrixCalcIOUtils();
-
             String stringMatrixA = matrixATextArea.getText();
             String stringMatrixB = matrixBTextArea.getText();
-            try {
+            String[] stringMatrix = { stringMatrixA, stringMatrixB };
 
-            } catch (Exception e) {
-                //TODO: handle exception
-            }
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 2);
 
             double[][] matrixA = util.stringToMatrix(stringMatrixA);
             double[][] matrixB = util.stringToMatrix(stringMatrixB);
@@ -97,25 +85,11 @@ public class MatrixCalcController {
         });
 
         substractButton.setOnMouseClicked((event) -> {
-            MatrixCalcMath math = new MatrixCalcMath();
-            MatrixCalcIOUtils util = new MatrixCalcIOUtils();
-
             String stringMatrixA = matrixATextArea.getText();
             String stringMatrixB = matrixBTextArea.getText();
+            String[] stringMatrix = { stringMatrixA, stringMatrixB };
             
-            try {
-                util.checkInput(stringMatrixA);
-            } catch (Exception e) {
-                outputText.setText(e.getMessage() + "A");
-                outputText.setTextAlignment(TextAlignment.CENTER);
-            }
-
-            try {
-                util.checkInput(stringMatrixB);
-            } catch (Exception e) {
-                outputText.setText(e.getMessage() + "B");
-                outputText.setTextAlignment(TextAlignment.CENTER);
-            }
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 2);
 
             double[][] matrixA = util.stringToMatrix(stringMatrixA);
             double[][] matrixB = util.stringToMatrix(stringMatrixB);
@@ -135,21 +109,13 @@ public class MatrixCalcController {
         });
 
         DetAButton.setOnMouseClicked((event) -> {
-            MatrixCalcMath math = new MatrixCalcMath();
-            MatrixCalcIOUtils util = new MatrixCalcIOUtils();
-
             String stringMatrixA = matrixATextArea.getText();
+            String[] stringMatrix = { stringMatrixA, "" };
 
-            try {
-
-                util.checkInput(stringMatrixA);
-
-            } catch (IllegalArgumentException e) {
-                outputText.setText(e.getMessage());
-                outputText.setTextAlignment(TextAlignment.CENTER);
-            }
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 1);
 
             double[][] matrixA = util.stringToMatrix(stringMatrixA);
+
             try {
                 double result = math.calcDeterminat(matrixA);
 
@@ -166,20 +132,13 @@ public class MatrixCalcController {
         });
 
         DetBButton.setOnMouseClicked((event) -> {
-            MatrixCalcMath math = new MatrixCalcMath();
-            MatrixCalcIOUtils util = new MatrixCalcIOUtils();
-
             String stringMatrixB = matrixBTextArea.getText();
-            try {
-
-                util.checkInput(stringMatrixB);
+            String[] stringMatrix = { "", stringMatrixB };
 
-            } catch (IllegalArgumentException e) {
-                outputText.setText(e.getMessage());
-                outputText.setTextAlignment(TextAlignment.CENTER);
-            }
+            checkInputAndDisplayIfInputIsNotValid(stringMatrix, 1);
 
             double[][] matrixB = util.stringToMatrix(stringMatrixB);
+
             try {
                 double result = math.calcDeterminat(matrixB);
 
@@ -195,4 +154,57 @@ public class MatrixCalcController {
             }
         });
     }
+
+    // TODO Wirte tests for the extracted Methode.
+    /**
+     * Checks the Input and Displays it if the Input is Valid.
+     * 
+     * @param stringMatrix            Contains both input matrices if
+     *                                numberOfMarriciesToMatch is 2. If the number
+     *                                is 1 than one of them has to be a empty String
+     * @param numberOfMatricesToMatch If the number is 1 onely one Marix will be
+     *                                verifyed and the otherone needs to be an empty
+     *                                String in the stringMatrix
+     */
+    private void checkInputAndDisplayIfInputIsNotValid(String[] stringMatrix, int numberOfMatricesToMatch) {
+        if (numberOfMatricesToMatch == 1 && !stringMatrix[0].equals("")) {
+            try {
+                util.checkInput(stringMatrix[0]);
+            } catch (Exception e) {
+                outputText.setText(e.getMessage() + "A");
+                outputText.setTextAlignment(TextAlignment.CENTER);
+            }
+        } else if (numberOfMatricesToMatch == 1 && !stringMatrix[1].equals("")) {
+            try {
+                util.checkInput(stringMatrix[1]);
+            } catch (Exception e) {
+                outputText.setText(e.getMessage() + "B");
+                outputText.setTextAlignment(TextAlignment.CENTER);
+            }
+        } else if (numberOfMatricesToMatch == 2 && !stringMatrix[0].equals("") && !stringMatrix[1].equals("")) {
+            try {
+                util.checkInput(stringMatrix[0]);
+            } catch (Exception e) {
+                outputText.setText(e.getMessage() + "A");
+                outputText.setTextAlignment(TextAlignment.CENTER);
+            }
+
+            try {
+                util.checkInput(stringMatrix[1]);
+            } catch (Exception e) {
+                outputText.setText(e.getMessage() + "B");
+                outputText.setTextAlignment(TextAlignment.CENTER);
+            }
+        } else if (stringMatrix[0].equals("")) {
+
+            outputText.setText("Pease insert MatrixA");
+            outputText.setTextAlignment(TextAlignment.CENTER);
+
+        } else if (stringMatrix[1].equals("")) {
+
+            outputText.setText("Pease insert MatrixB");
+            outputText.setTextAlignment(TextAlignment.CENTER);
+        }
+
+    }
 }