Obtener el último ID de un INSERT en Java

public int ejecuta_query(String Query) {  
 
  PreparedStatement pstmt;  
  int key = 0;  
 
 
  try {  
 	pstmt = conn.prepareStatement(Query, 
                                Statement.RETURN_GENERATED_KEYS);  
 
 	pstmt.executeUpdate();  
 	ResultSet keys = pstmt.getGeneratedKeys();  
 
 	keys.next();  
 	key = keys.getInt(1);  
 	keys.close();  
 	pstmt.close();  
 	conn.close();  
      } catch (Exception e) { e.printStackTrace(); }  
 
 	return key;  
 }

public int ejecuta_query(String Query) { PreparedStatement pstmt; int key = 0; try { pstmt = conn.prepareStatement(Query, Statement.RETURN_GENERATED_KEYS); pstmt.executeUpdate(); ResultSet keys = pstmt.getGeneratedKeys(); keys.next(); key = keys.getInt(1); keys.close(); pstmt.close(); conn.close(); } catch (Exception e) { e.printStackTrace(); } return key; }