Zayin Krige

Create XML output with RESTful webservices in JAVA

14 Dec 2009 @ 5:05 PM

In this article I would like to describe how to get your RESTful webservice to output XML. RESTful doesnt output as much detail as the SOAP specification, but it gives you enough data to work with, assuming you know what the data types are.

Firstly, create a class that represents your output. Remember the import!

^?View Code JAVA

import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement
public class userData {
    public String firstname;
    public String lastname;
    public String idnumber;
    public String pin;
    public int status;
}

Then we can start coding the webservice. I’m not going to go into detail, but am just going to put in the specifics that are relevant for this article

^?View Code JAVA

import java.util.ArrayList;
import java.util.List;
 
@Path("airtime_functions")
public class airtime {
    @GET
    @Path("get_users")
    @Produces("application/xml")
    public List<userData> get_users(@QueryParam("user_id") String user_id)
    {
        List<userData> retUser = new ArrayList<userData>();
        try
        {
            errorMsg = "";
            con = getJNDIConnection();
            stmt = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
            String sql = "SELECT * from users where user_id = ?";
            PreparedStatement prest = con.prepareStatement(sql);
            prest.setString(1, user_id);
            prest.execute();
            rs = prest.getResultSet();
            while (rs.next())
            {
                userData toReturn = new userData();
                toReturn.firstname = rs.getString("firstname");
                toReturn.idnumber = rs.getString("idnumber");
                toReturn.lastname = rs.getString("surname");
                toReturn.pin = rs.getString("pin");
                toReturn.status = rs.getInt("status");
                retUser.add(toReturn);
            }
            con.close();
            return retUser;
        } catch (Exception e)
        {
            userData toReturn = new userData();
            toReturn.firstname = "Error: " + e;
            toReturn.idnumber = "";
            toReturn.lastname = "";
            toReturn.pin = "";
            toReturn.status = 0;
            retUser.add(toReturn);
            return retUser;
        }
    }