source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/ClientSideServlet.java@ 28218

package org.greenstone.gsdl3;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringUtils;
import org.greenstone.gsdl3.util.Dictionary;
import org.greenstone.gsdl3.util.XSLTUtil;

public class ClientSideServlet extends BaseGreenstoneServlet
{
    public void init(ServletConfig config) throws ServletException
    {
        super.init(config);
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
    {
        String query_string = request.getQueryString();
        PrintWriter w = response.getWriter();

        if (query_string == null)
            displayParamError(response);

        String[] parts = StringUtils.split(query_string, "&");

        String[] keys = null; // Array of keys to look up
        String lang = "";
        String interface_name = "";
        String command = "";
        String params = "";

        for (String part : parts)
        {

            String[] nameval = StringUtils.split(part, '=');

            if (nameval.length != 2)
            {
                displayParamError(response);
                return;
            }

            String name = nameval[0];
            String value = nameval[1];

            if (name.equals("k"))
                keys = StringUtils.split(value, ",");
            else if (name.equals("l"))
                lang = value;
            else if (name.equals("i"))
                interface_name = value;
            else if (name.equals("c"))
                // Alternative commands
                command = value;
            else if (name.equals("p"))
                params = value;
        }

        if (keys == null && command.equals("") && params.equals(""))
        {
            // Not satisfiable
            displayParamError(response);
            return;
        }

        String bundle = "<?xml version=\"1.0\" encoding=\"iso-8859-1\" ?>\r\n<textBundle>\r\n";

        if (!command.equals("") && !params.equals(""))
        {

            // Alternative commands other than dictionary lookup
            String[] parameters = StringUtils.split(params, "|");
            String result = null;

            if (command.equals("getNumberedItem") && parameters.length == 2)
            {
                result = XSLTUtil.getNumberedItem(parameters[0], Integer.parseInt(parameters[1]));
            }
            else if (command.equals("exists") && parameters.length == 2)
            {
                result = XSLTUtil.exists(parameters[0], parameters[1]) ? "true" : "false";
            }
            else if (command.equals("isImage") && parameters.length == 1)
            {
                result = (XSLTUtil.isImage(parameters[0])) ? "true" : "false";
            }

            if (result != null)
            {
                bundle += " <method name=\"" + command + "\" parameters=\"" + params + "\" return=\"" + result + "\" />\r\n";
            }
            else
            {
                displayParamError(response);
                return;
            }
        }
        else
        {

            for (String key : keys)
            {

                String original_key = key;
                String[] theParts = StringUtils.split(key, "|");
                String[] args = null;

                if (theParts.length > 1)
                    args = StringUtils.split(theParts[1], ";");

                key = theParts[0];

                // Straight from XSLTUtils.java (src), with some modifications
                if (key.equals("null"))
                {
                    bundle += " <item key=\"" + key + "\" value=\"\" />\r\n";
                    continue;
                }

                Dictionary dict = new Dictionary("interface_" + interface_name, lang);
                String result = dict.get(key, args);

                if (result == null)
                {
                    String sep_interface_dir = interface_name + File.separatorChar + lang + File.separatorChar + "interface";
                    dict = new Dictionary(sep_interface_dir, lang);
                    result = dict.get(key, args);
                }

                if (result == null && !interface_name.equals("default"))
                { // not found, try the default interface
                    dict = new Dictionary("interface_default", lang);
                    result = dict.get(key, args);
                }

                if (result == null)
                { // not found
                    result = "_" + original_key + "_";
                }

                bundle += " <item key=\"" + encode(original_key) + "\" value=\"" + encode(result) + "\" />\r\n";
            }
        }

        bundle += "</textBundle>";

        response.setContentType("text/xml");

        w.print(bundle);
        w.close();
    }

    private String encode(String s)
    {
        s = StringUtils.replace(s, "&", "&amp;");
        s = StringUtils.replace(s, "<", "&lt;");
        s = StringUtils.replace(s, ">", "&gt;");
        return s;
    }

    private void displayParamError(HttpServletResponse response)
    {

        try
        {
            PrintWriter w = response.getWriter();
            w.write("Invalid parameters supplied! Need key (k=), interface name (i=) and language (l=). If you specified a method call, it must be on the list of supported method calls, and you must specify a command (c=) and parameters (p=).");
            w.close();
        }
        catch (Exception ex)
        { /* Should log here */
        }

    }

}