lab for today: made edits to files

.classpath

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

README.md

@@ -1,2 +1,4 @@
 # lab_browser
 A simple GUI example: a web browser
+
+by David Zhou (dz54) and Kevin Wang (kw197)

src/BrowserException.java

@@ -0,0 +1,6 @@
+
+public class BrowserException extends RuntimeException  {
+	public BrowserException(String s){
+		super(s);
+	}
+}

src/BrowserModel.java

@@ -4,6 +4,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.ResourceBundle;
 
 
 /**
@@ -18,6 +19,8 @@ public class BrowserModel {
     // state
     private URL myHome;
     private URL myCurrentURL;
+    private static final String errorResources = "resources/error";
+    private ResourceBundle myErrorResource;
     private int myCurrentIndex;
     private List<URL> myHistory;
     private Map<String, URL> myFavorites;
@@ -32,6 +35,7 @@ public BrowserModel () {
         myCurrentIndex = -1;
         myHistory = new ArrayList<>();
         myFavorites = new HashMap<>();
+        myErrorResource = ResourceBundle.getBundle(errorResources);
     }
 
     /**
@@ -42,7 +46,8 @@ public URL next () {
             myCurrentIndex++;
             return myHistory.get(myCurrentIndex);
         }
-        return null;
+        throw new BrowserException(myErrorResource.getString("next"));
+
     }
 
     /**
@@ -53,7 +58,7 @@ public URL back () {
             myCurrentIndex--;
             return myHistory.get(myCurrentIndex);
         }
-        return null;
+        throw new BrowserException(myErrorResource.getString("back"));
     }
 
     /**
@@ -119,7 +124,7 @@ public URL getFavorite (String name) {
         if (name != null && !name.equals("") && myFavorites.containsKey(name)) {
             return myFavorites.get(name);
         }
-        return null;
+        throw new BrowserException(myErrorResource.getString("getFavorite"));
     }
 
     // deal with a potentially incomplete URL
@@ -137,7 +142,7 @@ private URL completeURL (String possible) {
                     // e.g., let user leave off initial protocol
                     return new URL(PROTOCOL_PREFIX + possible);
                 } catch (MalformedURLException eee) {
-                    return null;
+                    throw new BrowserException(myErrorResource.getString("completeURL"));
                 }
             }
         }