Fixed some warnings and added toString function in JSONObjectStream

src/zutil/db/bean/DBBeanSQLResultHandler.java

@@ -45,7 +45,7 @@ public class DBBeanSQLResultHandler<T> implements SQLResultHandler<T>{
 	public static final long CACHE_DATA_TTL = 1000*60*5; // 5 min in ms
 	/** A cache for detecting recursion **/
 	protected static Map<Class<?>, Map<Long,DBBeanCache>> cache =
-		new ConcurrentHashMap<Class<?>, Map<Long,DBBeanCache>>();
+		new ConcurrentHashMap<>();
 	private static Timer timer;
 
     static {
@@ -283,7 +283,7 @@ public class DBBeanSQLResultHandler<T> implements SQLResultHandler<T>{
 		} finally{
 			obj.processing_update = false;
 		}
-		
+
 		obj.postUpdateAction();
 	}
 

src/zutil/parser/json/JSONObjectOutputStream.java

@@ -25,6 +25,7 @@
 package zutil.parser.json;
 
 import zutil.ClassUtil;
+import zutil.io.StringOutputStream;
 import zutil.parser.Base64Encoder;
 import zutil.parser.DataNode;
 import zutil.parser.DataNode.DataType;
@@ -52,7 +53,7 @@ public class JSONObjectOutputStream extends OutputStream implements ObjectOutput
     private JSONWriter out;
 
     private JSONObjectOutputStream() {
-        this.objectCache = new HashMap<Object, Integer>();
+        this.objectCache = new HashMap<>();
     }
     public JSONObjectOutputStream(OutputStream out) {
         this();
@@ -64,6 +65,21 @@ public class JSONObjectOutputStream extends OutputStream implements ObjectOutput
     }
 
 
+    /**
+     * @return a String containing the JSON representation of the Object
+     */
+    public static String toString(Object obj){
+        try {
+            StringOutputStream out = new StringOutputStream();
+            JSONObjectOutputStream writer = new JSONObjectOutputStream(out);
+            writer.writeObject(obj);
+            writer.close();
+            return out.toString();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
 
     public synchronized void writeObject(Object obj) throws IOException{
         try{

src/zutil/parser/json/JSONWriter.java

@@ -132,7 +132,7 @@ public class JSONWriter{
     }
 
     /**
-     * @return JSON String that is generated from the input DataNode graph
+     * @return a String containing the JSON representation of the input DataNode graph
      */
     public static String toString(DataNode root){
         StringOutputStream out = new StringOutputStream();