JAVA-563: refactored queryopbuilder

Author: Steve Briskin

src/main/com/mongodb/DBCollection.java

@@ -676,12 +676,12 @@ public DBObject findOne( DBObject o, DBObject fields ) {
      * Returns a single obejct from this collection matching the query.
      * @param o the query object
      * @param fields fields to return
-     * @param orderby fields to order by
+     * @param orderBy fields to order by
      * @return the object found, or <code>null</code> if no such object exists
      * @dochub find
      */
-    public DBObject findOne( DBObject o, DBObject fields, DBObject orderby){
-    	return findOne(o, fields, orderby, getReadPreference());
+    public DBObject findOne( DBObject o, DBObject fields, DBObject orderBy){
+    	return findOne(o, fields, orderBy, getReadPreference());
     }
 
     /**
@@ -699,15 +699,15 @@ public DBObject findOne( DBObject o, DBObject fields, ReadPreference readPref )
      * Returns a single object from this collection matching the query.
      * @param o the query object
      * @param fields fields to return
-     * @param orderby fields to order by
+     * @param orderBy fields to order by
      * @return the object found, or <code>null</code> if no such object exists
      * @dochub find
      */
-    public DBObject findOne( DBObject o, DBObject fields, DBObject orderby, ReadPreference readPref ) {
+    public DBObject findOne( DBObject o, DBObject fields, DBObject orderBy, ReadPreference readPref ) {
 
     	DBObject queryop = new QueryOpBuilder()
     								.addQuery(o)
-    								.addOrderBy(orderby)
+    								.addOrderBy(orderBy)
     								.get();
 
     	Iterator<DBObject> i = __find( queryop, fields , 0 , -1 , 0, getOptions(), readPref, getDecoder() );

src/main/com/mongodb/DBCursor.java

@@ -343,34 +343,17 @@ public int getOptions(){
 
     // ----  internal stuff ------
 
-    private void _check()
-        throws MongoException {
-        if ( _it != null )
-            return;
+	private void _check() throws MongoException {
+		if (_it != null)
+			return;
 
-        _lookForHints();
-
-        DBObject foo = _query;
-        if (hasSpecialQueryFields()) {
-            QueryOpBuilder opbuilder = (_specialFields == null ? new QueryOpBuilder() : new QueryOpBuilder(_specialFields));
-    
-            opbuilder.addQuery(_query)
-            	.addOrderBy(_orderBy)
-            	.addHint(_hint)
-            	.addHint(_hintDBObj);
-            
-            if(_explain)
-            		opbuilder.addExplain();
-            if(_snapshot)
-            		opbuilder.addSnapshot();
-            
-            foo = opbuilder.get();
-        }
-
-        _it = _collection.__find(foo, _keysWanted, _skip, _batchSize, _limit, _options, _readPref, getDecoder());
-    }
+		_lookForHints();
 
- 
+		DBObject queryOp = new QueryOpBuilder(_query, _orderBy, _hintDBObj, _hint, _explain, _snapshot, _specialFields).get();
+		
+		_it = _collection.__find(queryOp, _keysWanted, _skip, _batchSize, _limit,
+				_options, _readPref, getDecoder());
+	}
 
 	// Only create a new decoder if there is a decoder factory explicitly set on the collection.  Otherwise return null
     // so that the collection can use a cached decoder
@@ -403,19 +386,6 @@ private void _lookForHints(){
         }
     }
 
-    boolean hasSpecialQueryFields(){
-        if ( _specialFields != null )
-            return true;
-
-        if ( _orderBy != null && _orderBy.keySet().size() > 0 )
-            return true;
-        
-        if ( _hint != null || _hintDBObj != null || _snapshot )
-            return true;
-
-        return _explain;
-    }
-
     void _checkType( CursorType type ){
         if ( _cursorType == null ){
             _cursorType = type;

src/main/com/mongodb/QueryOpBuilder.java

@@ -5,42 +5,52 @@
 
 
 /**
- * Utility for constructing Query operation command with query, orderby, hint, explain, snapshot
+ * Utility for constructing Query operation command with query, orderby, hint, explain, snapshot.
  */
-public class QueryOpBuilder {
-	private DBObject queryop;
+class QueryOpBuilder {
+	
+	private DBObject query;
+	private DBObject orderBy;
+	private DBObject hintObj;
+	private String hintStr;
+	private boolean explain;
+	private boolean snapshot;
 
-	/**
-	 * Creates a builder with an empty query op
-	 */
+	private DBObject specialFields;
+	
 	public QueryOpBuilder(){
-		queryop = new BasicDBObject();
 	}
 
-	/**
-	 * Creates a new builder
-	 * @param queryop
-	 */
-	public QueryOpBuilder(DBObject queryop){
-		this.queryop = queryop;
+	public QueryOpBuilder(DBObject query, DBObject orderBy, DBObject hintObj, String hintStr, boolean explain, boolean snapshot,
+			DBObject specialFields) {
+		this.query = query;
+		this.orderBy = orderBy;
+		this.hintObj = hintObj;
+		this.hintStr = hintStr;
+		this.explain = explain;
+		this.snapshot = snapshot;
+		this.specialFields = specialFields;
 	}
-	
+
+
 	/**
 	 * Adds the query clause to the operation
 	 * @param query
 	 * @return
 	 */
 	public QueryOpBuilder addQuery(DBObject query){
-		return addToQueryObject("query", query, true);
+		this.query = query;
+		return this;
 	}
 
 	/**
-	 * Adds the groupby clause to the operation
+	 * Adds the orderby clause to the operation
 	 * @param orderBy
 	 * @return
 	 */
 	public QueryOpBuilder addOrderBy(DBObject orderBy){
-		return addToQueryObject("orderby", orderBy, false);	
+		this.orderBy = orderBy;
+		return this;	
 	}
 
 	/**
@@ -49,75 +59,124 @@ public QueryOpBuilder addOrderBy(DBObject orderBy){
 	 * @return
 	 */
 	public QueryOpBuilder addHint(String hint){
-		if(hint != null)
-			 addToQueryObject("$hint", hint);
-		
+		this.hintStr = hint;
 		return this;
 	}
 
+	/**
+	 * Adds hint clause to the operation
+	 * @param hint
+	 * @return
+	 */
 	public QueryOpBuilder addHint(DBObject hint){
-		if(hint != null)
-			addToQueryObject("$hint", hint, false);
-		
+		this.hintObj = hint;
+		return this;
+	}
+	
+	
+	/**
+	 * Adds special fields to the operation
+	 * @param specialFields
+	 * @return
+	 */
+	public QueryOpBuilder addSpecialFields(DBObject specialFields){
+		this.specialFields = specialFields;
 		return this;
 	}
 
 	/**
 	 * Adds the explain flag to the operation
+	 * @param explain
 	 * @return
 	 */
-	public QueryOpBuilder addExplain(){
-		return addToQueryObject("$explain", true);
+	public QueryOpBuilder addExplain(boolean explain){
+		this.explain = explain;
+		return this;
 	}
 
 	/**
 	 * Adds the snapshot flag to the operation
+	 * @param snapshot
 	 * @return
 	 */
-	public QueryOpBuilder addSnapshot(){
-		return addToQueryObject("$snapshot", true);
+	public QueryOpBuilder addSnapshot(boolean snapshot){
+		this.snapshot = snapshot;
+		return this;
+	}
+
+	
+	/**
+	 * Constructs the query operation DBObject
+	 * @return DBObject representing the query command to be sent to server
+	 */
+	public DBObject get(){
+		if(hasSpecialQueryFields()){
+			DBObject queryop = (specialFields == null ? new BasicDBObject() : specialFields);
+
+            addToQueryObject(queryop, "query", query, true);
+            addToQueryObject(queryop, "orderby", orderBy, false);
+            if (hintStr != null)
+                addToQueryObject(queryop, "$hint", hintStr);
+            if (hintObj != null)
+                addToQueryObject(queryop, "$hint", hintObj);
+
+            if (explain)
+                queryop.put("$explain", true);
+            if (snapshot)
+                queryop.put("$snapshot", true);
+
+            return queryop;
+		}
 
+		return query;
 	}
 
+    private boolean hasSpecialQueryFields(){
+        if ( specialFields != null )
+            return true;
+
+        if ( orderBy != null && orderBy.keySet().size() > 0 )
+            return true;
+        
+        if ( hintStr != null || hintObj != null || snapshot || explain)
+            return true;
+
+        return false;
+    }
+	
 	/**
 	 * Adds DBObject to the operation
+	 * @param dbobj DBObject to add field to
 	 * @param field name of the field
 	 * @param obj object to add to the operation.  Ignore if <code>null</code>.
 	 * @param sendEmpty if <code>true</code> adds obj even if it's empty.  Ignore if <code>false</code> and obj is empty.
 	 * @return
 	 */
-	public QueryOpBuilder addToQueryObject(String field, DBObject obj, boolean sendEmpty) {
+	private void addToQueryObject(DBObject dbobj, String field, DBObject obj, boolean sendEmpty) {
 		if (obj == null)
-			return this;
+			return;
 
 		if (!sendEmpty && obj.keySet().size() == 0)
-			return this;
+			return;
 
-		return addToQueryObject(field, obj);
+		addToQueryObject(dbobj, field, obj);
 	}
 
 	/**
 	 * Adds an Object to the operation
+	 * @param dbobj DBObject to add field to
 	 * @param field name of the field
 	 * @param obj Object to be added.  Ignore if <code>null</code>
 	 * @return
 	 */
-	public QueryOpBuilder addToQueryObject(String field, Object obj) {
+	private void addToQueryObject(DBObject dbobj, String field, Object obj) {
 
 		if (obj == null)
-			return this;
+			return;
 
-		queryop.put(field, obj);
-
-		return this;
+		dbobj.put(field, obj);
 	}
 
-	/**
-	 * gets the constructed query operation object
-	 * @return
-	 */
-	public DBObject get(){
-		return queryop;
-	}
+	
 
 }