zipdbservlet.java

ajax修炼之道源代码。很难下到的。现在奉献给大家。

/***
 * Excerpted from "Pragmatic Ajax"
 * We make no guarantees that this code is fit for any purpose. 
 * Visit http://www.pragmaticprogrammer.com/titles/ajax for more book information.
***/
package ajaxian.book.crm.servlet;

import ajaxian.book.crm.model.ZipCityState;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletConfig;
import java.io.PrintWriter;
import java.io.IOException;
import java.sql.*;

public class ZipDbServlet extends HttpServlet {
    private boolean debug = false;

    public void init(ServletConfig servletConfig) {
        if ("true".equals(servletConfig.getInitParameter("DEBUG"))) {
            debug = true;
        }
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        String zip = request.getParameter("zip");

        ZipCityState zcs = null;
        if (zip != null) {
            try {
                zcs = getZipCityState(zip);
            } catch (SQLException e) {
                debug(e.toString());
                zcs = new ZipCityState(zip, "Durham", "NC");
            }
        } else {
            zcs = new ZipCityState(zip, "No City", "XX");
        }

        String type = request.getParameter("type");
        if ("html".equalsIgnoreCase(type)) {
            debug("Returning HTML result for zip: " + zip);
            out.println("<th>City:</th><td><input id='city' type='text' name='city' value='" + zcs.getCity() + "'/></td><th>State:</th><td><input id='state' type='text' name='state' size='2' maxlength='2' value='" + zcs.getState() + "'/></td>");
            /*

<tr id="rewrite">
    <th>City:</th>
    <td><input id="city" type="text" name="city"/></td>
    <th>State:</th>
    <td><input id="state" type="text" name="state"/></td>
</tr>

            */
        } else if ("eval".equalsIgnoreCase(type)) {
            debug("Returning eval result for zip: " + zip);
            out.println("document.getElementById('city').value = '" + zcs.getCity() + "';document.getElementById('state').value = '" + zcs.getState() + "';document.getElementById('zipError').innerHTML = '';");
            /*
document.getElementById('city').value = 'Boulder';
document.getElementById('state').value = 'CO';
document.getElementById('zipError').innerHTML = '';
            */
        } else if ("evalproto".equalsIgnoreCase(type)) {
            debug("Returning prototype style eval result for zip: " + zip);
            out.println("$('city').value = '" + zcs.getCity() + "';$('state').value = '" + zcs.getState() + "';$('zipError').innerHTML = '';");
            /*
$('city').value = 'Boulder';
$('state').value = 'CO';
$('zipError').innerHTML = '';
            */
        } else {
            debug("Returning 'City,State' result for zip: " + zip);
            if(zcs != null) {
               out.println(zcs.getCity() + "," + zcs.getState());
            } else {
               out.println("Durham,NC");
            }

        }
    }

    private static ZipCityState getZipCityState(String zip) throws SQLException {
        PreparedStatement ps = getConnection().prepareStatement("SELECT city, state FROM zips WHERE zip=?");
        ps.setString(1, zip);
        ResultSet rs = ps.executeQuery();
        rs.next();
        return new ZipCityState(zip, rs.getString("city"), rs.getString("state"));
    }
    
    private static Connection getConnection() throws SQLException {
        try {
            Class.forName("org.hsqldb.jdbcDriver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }
        return DriverManager.getConnection("jdbc:hsqldb:hsql://localhost:8585/crm", "sa", "");
    }

    /**
     * Cheesy logging
     * @param info
     */
    private void debug(String info) {
        if (debug) System.out.println(info);
    }

}