completed lab

src/main/java/rocks/zipcode/NumericCharDocument.java

@@ -12,9 +12,16 @@ public class NumericCharDocument extends Document {
 
     @Override
     public void write(String contentToBeWritten) {
+        try {
+            isNumeric(contentToBeWritten);
+            super.write(contentToBeWritten);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
     }
 
-    private Boolean isNumeric(String s) {
-        return null;
+    private void isNumeric(String s) throws IOException{
+        if(!s.matches("[0-9\\s]*"))
+            throw new IllegalArgumentException();
     }
 }

src/main/java/rocks/zipcode/SpecialCharDocument.java

@@ -12,9 +12,16 @@ public class SpecialCharDocument extends Document {
 
     @Override
     public void write(String contentToBeWritten) {
+        try {
+            isSpecialCharacters(contentToBeWritten);
+            super.write(contentToBeWritten);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
     }
 
-    private Boolean isSpecialCharacters(String s) {
-        return null;
+    private void isSpecialCharacters(String s) throws IOException {
+        if(!s.matches("[\\W_]*"))
+            throw new IllegalArgumentException();
     }
 }