Added minor error handling, fixed NullPointer

src/main/data/DataSource.java

@@ -5,6 +5,7 @@ import java.util.Map;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Objects;
+import java.io.IOException;
 
 public abstract class DataSource {
     protected HashMap<String, StockType> targets;
@@ -65,5 +66,5 @@ public abstract class DataSource {
         return Objects.hash(name);
     }
 
-    public abstract double[] update(String stype, String idstring);
+    public abstract double[] update(String stype, String idstring) throws IOException;
 }

src/main/data/StockEntry.java

@@ -1,6 +1,7 @@
 package data;
 
 import java.util.Objects;
+import java.io.IOException;
 
 public class StockEntry {
     private String identifier;
@@ -17,7 +18,14 @@ public class StockEntry {
     public boolean update() {
         boolean changed = false;
         updating = true;
-        double[] result = this.stype.update(this.identifier);
+        double[] result;
+        try {
+            result = this.stype.update(this.identifier);
+        } catch (IOException e) {
+            System.out.println("Error getting update");
+            e.printStackTrace();
+            return false;
+        }
         if ((result[0] != price) || (result[1] != change)) {
             changed = true;
         }

src/main/data/StockType.java

@@ -1,6 +1,7 @@
 package data;
 
 import java.util.*;
+import java.io.IOException;
 
 public abstract class StockType {
     protected String name;
@@ -14,7 +15,7 @@ public abstract class StockType {
     //Effects: return current price[0] and %change[1] 
     //				(2 element array)
     //Require: working sources
-    public double[] update(String idstring) {
+    public double[] update(String idstring) throws IOException {
         double[] result = {0.0, 0.0};
         for (DataSource source : sources) {
             double[] sourceRes = source.update(name, idstring);

src/main/data/WatchList.java

@@ -142,11 +142,9 @@ public class WatchList extends Observable implements Load,Save {
             }
             sentry.update();
         }
-        if (changed) {
         setChanged();
         notifyObservers(new Wevent(Etype.UPDATE));
     }
-    }
 
     public class Wevent {
         private Etype type;

src/main/network/AlphaVantage.java

@@ -13,7 +13,7 @@ public class AlphaVantage extends DataSource {
     }
 
     @Override
-    public double[] update(String stype, String idstring) {
+    public double[] update(String stype, String idstring) throws IOException {
         double[] result = {0.0, 0.0};
         try {
             String urlString = Net.urlStringBuilder(url, "function", "TIME_SERIES_INTRADAY", "symbol", idstring,
@@ -21,17 +21,20 @@ public class AlphaVantage extends DataSource {
                     "apikey", apiKey);
             JsonObject response = StockJson.urlToJson(urlString);
             JsonObject preJson = StockJson.jsonInJson(response, "Time Series (5min)");
+            if (preJson == null) {
+                throw new IOException("Error getting data from " + name);
+            }
             JsonObject mainJson = StockJson.timeSeriesElement(preJson, 0);
-            System.out.print(mainJson);
+            //System.out.print(mainJson);
             result[0] = Double.parseDouble(StockJson.stringGetter(mainJson, "4. close"));
             Double open = Double.parseDouble(StockJson.stringGetter(mainJson, "1. open"));
             result[1] = (result[0] - open) / open;
         } catch (ParaMismatchException e) {
             e.printStackTrace();
-        } catch (IOException e) {
-            System.out.println("Error getting data from: " + name);
+        } //catch (IOException e) {
+           // System.out.println("Error getting data from: " + name);
             //e.printStackTrace();
-        }
+        //}
         return result;
     }
 }

src/main/network/StockJson.java

@@ -47,6 +47,7 @@ public class StockJson {
     // From https://stackoverflow.com/questions/33531041/jsonobject-get-value-of-first-node-regardless-of-name
     public static JsonObject timeSeriesElement(JsonObject jobj, int index) {
         String name = (String) jobj.keySet().toArray()[index];
+	System.out.println(name);
         return jsonInJson(jobj, name);
     }
 }

src/main/ui/guicomp/AddButt.java

@@ -11,7 +11,10 @@ public class AddButt extends JButton {
 
     public AddButt(WatchList wlist) {
         super("Add Stock...");
+        //https://coderanch.com/t/580497/java/JButton-clicked-action
+        if (getActionListeners().length < 1) {
             addActionListener(new AddButtList());
+        }
         this.wlist = wlist;
     }
 
@@ -19,9 +22,9 @@ public class AddButt extends JButton {
         public void actionPerformed(ActionEvent e) {
             //https://docs.oracle.com/javase/tutorial/uiswing/components/dialog.html#input
             //https://docs.oracle.com/javase/7/docs/api/javax/swing/JOptionPane.html
+            System.out.println("Count of listeners: " + ((JButton) e.getSource()).getActionListeners().length);
             String userin = (String)JOptionPane.showInputDialog("Enter the identifier:");
             if ((userin != null) && (userin.length() > 0)) {
-                //https://stackoverflow.com/questions/12771500/best-way-of-creating-and-using-an-anonymous-runnable-class
                 new Thread(new Runnable() {
                     @Override
                     public void run() {

src/main/ui/guicomp/DelButt.java

@@ -12,7 +12,9 @@ public class DelButt extends JButton {
 
     public DelButt(WatchList wlist) {
         super("Remove Stock...");
+        if (getActionListeners().length < 1) {
             addActionListener(new DelButtList());
+        }
         this.wlist = wlist;
     }
 

src/main/ui/guicomp/UpButt.java

@@ -10,7 +10,9 @@ public class UpButt extends JButton {
 
     public UpButt(WatchList wlist) {
         super("Update");
+        if (getActionListeners().length < 1) {
             addActionListener(new UpButtList());
+        }
         this.wlist = wlist;
     }
 

src/test/data/NasdaqTest.java

@@ -8,6 +8,7 @@ import org.junit.jupiter.api.Test;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
 
 public class NasdaqTest {
     private StockType naasdaq;
@@ -24,6 +25,10 @@ public class NasdaqTest {
 
     @Test
     public void testUpdate() {
+        try {
             double[] farray = naasdaq.update("MSFT");
+        } catch (Exception e) {
+            fail();
+        }
     }
 }

src/test/data/NyseTest.java

@@ -8,6 +8,7 @@ import org.junit.jupiter.api.Test;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
 
 public class NyseTest {
     private StockType nyyyse;
@@ -24,7 +25,11 @@ public class NyseTest {
 
     @Test
     public void testUpdate() {
+        try {
             double[] farray = nyyyse.update("MSFT");
+        } catch (Exception e) {
+            fail();
+        }
     }
 
     @Test