Implemented suggestions from the code review of r436: throwing NoSuchElementException in case the stream hits EOF.

gson/src/main/java/com/google/gson/JsonStreamParser.java

@@ -19,6 +19,7 @@ import java.io.EOFException;
 import java.io.Reader;
 import java.io.StringReader;
 import java.util.Iterator;
+import java.util.NoSuchElementException;
 
 /**
  * A streaming parser that allows reading of multiple {@link JsonElement}s from the specified reader
@@ -31,7 +32,6 @@ import java.util.Iterator;
 public final class JsonStreamParser implements Iterator<JsonElement> {
 
   private final JsonParserJavacc parser;
-  private boolean eof;
   private JsonElement nextElement;
 
   /**
@@ -48,7 +48,6 @@ public final class JsonStreamParser implements Iterator<JsonElement> {
    */
   public JsonStreamParser(Reader reader) {
     parser = new JsonParserJavacc(reader);      
-    eof = false;
     nextElement = null;
   }
   
@@ -60,17 +59,13 @@ public final class JsonStreamParser implements Iterator<JsonElement> {
    * @since 1.4
    */
   public JsonElement next() throws JsonParseException {
-    if (eof) {
-      return null;
-    }
     if (nextElement != null) {
       JsonElement returnValue = nextElement;
       nextElement = null;
       return returnValue;
     }
     try {
-      JsonElement element = parser.parse();
-      return element;
+      return parser.parse();
     } catch (TokenMgrError e) {
       throw new JsonParseException("Failed parsing JSON source to Json", e);
     } catch (ParseException e) {
@@ -81,8 +76,7 @@ public final class JsonStreamParser implements Iterator<JsonElement> {
       throw new JsonParseException("Failed parsing JSON source to Json", e);
     } catch (JsonParseException e) {
       if (e.getCause() instanceof EOFException) {
-        eof = true;
-        return null;
+        throw new NoSuchElementException();
       } else {
         throw e;
       }
@@ -90,8 +84,13 @@ public final class JsonStreamParser implements Iterator<JsonElement> {
   }
 
   public boolean hasNext() {
-    nextElement = next();
-    return nextElement != null;
+    try {
+      nextElement = next();
+      return true;
+    } catch (NoSuchElementException e) {
+      nextElement = null;
+      return false;
+    }
   }
 
   public void remove() {

gson/src/test/java/com/google/gson/JsonStreamParserTest.java

@@ -1,9 +1,10 @@
 package com.google.gson;
 
-import java.util.Iterator;
-
 import junit.framework.TestCase;
 
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
 /**
  * Unit tests for {@link JsonStreamParser}
  *
@@ -27,4 +28,15 @@ public class JsonStreamParserTest extends TestCase {
     assertEquals("two", parser.next().getAsString());
     assertFalse(parser.hasNext());
   }
+  
+  public void testCallingNextBeyondAvailableInput() {
+    Iterator<JsonElement> parser = new JsonStreamParser("'one' 'two'");
+    parser.next();
+    parser.next();
+    try {
+      parser.next();
+      fail("Parser should not go beyond available input");
+    } catch (NoSuchElementException expected) {
+    }
+  }
 }

gson/src/test/java/com/google/gson/functional/ReadersWritersTest.java

@@ -17,7 +17,6 @@ package com.google.gson.functional;
 
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
-import com.google.gson.JsonElement;
 import com.google.gson.JsonStreamParser;
 import com.google.gson.common.TestTypes.BagOfPrimitives;
 
@@ -112,7 +111,6 @@ public class ReadersWritersTest extends TestCase {
     assertEquals("one", actualOne.stringValue);
     BagOfPrimitives actualTwo = gson.fromJson(parser.next(), BagOfPrimitives.class);
     assertEquals("two", actualTwo.stringValue);
-    JsonElement jsonElement = parser.next();
-    assertNull(jsonElement);
+    assertFalse(parser.hasNext());
   }
 }