As of Java 1.7 implementations of JDBC interfaces Connection, Statement, PreparedStatement, CallableStatement and ResulSet must implement the AutoCloseable interface with method close(). This method is invoked automatically on objects managed by the try-with-resources statement. See http://docs.oracle.com/javase/7/docs/technotes/guides/language/try-with-resources.html http://docs.oracle.com/javase/7/docs/api/java/lang/AutoCloseable.html http://docs.oracle.com/javase/7/docs/api/java/sql/Connection.html http://docs.oracle.com/javase/7/docs/api/java/sql/Statement.html http://docs.oracle.com/javase/7/docs/api/java/sql/PreparedStatement.html http://docs.oracle.com/javase/7/docs/api/java/sql/CallableStatement.html http://docs.oracle.com/javase/7/docs/api/java/sql/ResultSet.html

--- a/src/main/java/nl/cwi/monetdb/jdbc/MonetPreparedStatement.java
+++ b/src/main/java/nl/cwi/monetdb/jdbc/MonetPreparedStatement.java
@@ -66,7 +66,7 @@ import java.util.Map;
  */
 public class MonetPreparedStatement
 	extends MonetStatement
-	implements PreparedStatement
+	implements PreparedStatement, AutoCloseable
 {
 	private final String[] monetdbType;
 	private final int[] javaType;