You can use ResultSetMetaData to retrieve metadata about the results of a query.

The query can contain any of the following:

• Aliases
• Fully qualified names
• Generated columns

You can instantiate a ResultSetMetaData object by invoking the getMetaData method of the Statement class. A ResultSetMetaData instance is populated with data after the statement has been executed. The following query prints out the columns in the result of the query:

String connectionString = "jdbc:informix:Server=10.0.1.2;Port=50000;User=admin;Password=admin;Database=test";

Connection conn = DriverManager.getConnection(connectionString);
PreparedStatement pstmt = conn.prepareStatement("SELECT Id, Author AS My_Author, GETDATE() FROM [informix].Books WHERE Category = 'US'");
pstmt.executeQuery();
ResultSetMetaData rs = pstmt.getMetaData();
for(int i=1;i<=rs.getColumnCount();i++) {
  System.out.println(rs.getColumnName(i));
}