guestbookapp.java

java 写的一个新闻发布系统

package components.guestbook;

import java.io.*;						// IOException
import java.util.*;                     // Hashtable
import javax.servlet.*;                 // ServletConfig
import javax.servlet.http.*;            // HttpServletRequest, HttpServletResponse

import org.jahia.services.applications.*;    // JahiaApplication
import org.jahia.params.*;          // ParamBean
import org.jahia.utils.*;
import org.jahia.exceptions.*;


public class GuestBookApp extends HttpServlet {


    private String version = "1.5";

    private static final String ENTRIES_PATH    = File.separator + "guestbook" + File.separator + "data" + File.separator;
    private static final String ENTRIES_FILE    = "entries.txt";
    private static final String TEMPLATE_PATH   = File.separator + "guestbook" + File.separator + "templates" + File.separator;
    private static final String TEMPLATE_FILE   = "std.html";

    /***
        * doGet
        * EV    10.12.2000
        *
        */
    public void doGet( HttpServletRequest request, HttpServletResponse response ) throws IOException
    {
        PrintWriter out = response.getWriter();


        //System.out.println( "GuestBook App ver" + version + " responding to " + request.getRemoteAddr() + " GET METHOD ");
        ParamBean jParams = (ParamBean) request.getAttribute( "org.jahia.params" );
        if (jParams == null)
        return;
        checkEntriesFile( jParams );
        if (request.getParameter("gb_flush") != null) {
            //System.out.println("Guestbook. Flushing entries...");
            flushEntries( request, jParams );
        }
        out.println(drawForm( request, response, jParams ) );
    } // end doGet



    /***
        * doPost
        * EV    10.12.2000
        *
        */
    public void doPost( HttpServletRequest request, HttpServletResponse response ) throws IOException
    {
        //System.out.println( "GuestBook App ver" + version + " responding to " + request.getRemoteAddr() + " POST METHOD ");
        BufferedReader requestReader = null;

        try {
            requestReader = request.getReader();
        } catch (IOException ioe) {
        //System.out.println("Guestbook : IOException while trying to recuperate input stream");
        } catch (IllegalStateException ise) {
            //System.out.println("Guestbook : IllegalStateException means InputStream has already been called on the request body");
        }

            if (requestReader == null) {
            //System.out.println("Guestbook : ERROR RETRIEVING INPUT STREAM !");
        } else {
            try {
                requestReader.reset();
        } catch (IOException ioe) {
            //System.out.println("Guestbook : IOException while resetting input stream");
        }
        try {
                //System.out.println("Guestbook : REQUEST BODY START ----- ");
            int nc = requestReader.read();
            while (nc != -1) {
                    //System.out.print((char)nc);
                nc = requestReader.read();
            }
                //System.out.println("Guestbook : REQUEST BODY END ----- ");
        } catch (IOException ioe) {
            //System.out.println("Guestbook : IOException while reading body of request");
        }

        }

        ParamBean jParams = (ParamBean) request.getAttribute( "org.jahia.params" );
        if (jParams == null)
        return;
        saveEntry( request, jParams );
        doGet( request, response );
    } // end doPost



    /***
        * flushEntries
        * EV    11.12.2000
        *
        */
    public void flushEntries( HttpServletRequest request, ParamBean jParams )
    {
        if (request.getParameter("gb_flush").equals("true")) {
            //System.out.println( "Flushing !!!! \n" ) ;
            String fileName = jParams.settings().getComponentsDiskPath() + ENTRIES_PATH + ENTRIES_FILE;
            try {
                FileUtils.getInstance().writeFile( fileName, " " );
            } catch (Exception e) {
                //System.out.println( "GuestBook App > Error in trying to flush data file : " + e );
            }
        }
    } // end flushEntries



    /***
        * checkEntriesFile
        * EV    11.12.2000
        *
        */
    public void checkEntriesFile( ParamBean jParams )
    {
        String filePath = jParams.settings().getComponentsDiskPath() + ENTRIES_PATH;
        String fileName = jParams.settings().getComponentsDiskPath() + ENTRIES_PATH + ENTRIES_FILE;
        File entriesPath = new File( filePath );
        if (!entriesPath.exists()) {
            entriesPath.mkdirs();
        }
        File entriesFile = new File( fileName );
        if (!entriesFile.exists()) {
            try {
                FileUtils.getInstance().writeFile( fileName, " " );
            } catch (Exception e) {
                //System.out.println( "GuestBook App > Error in trying to create data file : " + e );
            }
        }
    } // end



    /***
        * saveEntry
        * EV    10.12.2000
        *
        */
    public void saveEntry( HttpServletRequest request, ParamBean jParams )
    {
        String contents = "";
        String filePath = jParams.settings().getComponentsDiskPath() + ENTRIES_PATH + ENTRIES_FILE;
        try {
            contents = FileUtils.getInstance().readFile( filePath );
        } catch (Exception e) {
            //System.out.println( "GuestBook App > Error occured : " + e );
        }
        String comment = request.getParameter( "gb_comment" );
        String author  = request.getParameter( "gb_author" );
        String line = "<table border=\"0\" width=\"100%\">\n";
        line += "<tr><td width=\"100%\"><font face=\"arial\" size=\"2\" color=\"white\">\n";
        line += comment + "\n";
        line += "</font></td></tr>\n";
        line += "<tr><td align=\"right\">\n";
        line += "<font face=\"arial\" size=\"1\" color=\"white\"><i>" + author + "</i></font>\n";
        line += "</td></tr>\n";
        line += "<tr><td><hr noshade></td></tr></table>\n";
        contents += line;
        try {
            FileUtils.getInstance().writeFile( filePath, contents );
        } catch (Exception e) {
            //System.out.println( "GuestBook App > Error occured : " + e );
        }
    } // end saveEntry



    /***
        * loadEntries
        * EV    10.12.2000
        *
        */
    public String loadEntries( HttpServletRequest request, ParamBean jParams )
    {
        String contents = "";
        String filePath = jParams.settings().getComponentsDiskPath() + ENTRIES_PATH + ENTRIES_FILE;
        try {
            contents = FileUtils.getInstance().readFile( filePath );
        } catch (Exception e) {
            //System.out.println( "GuestBook App > Error occured : " + e );
            contents = "- Error in reading data file -";
        }
        return contents;
    } // end loadEntries



    /***
        * drawForm
        * EV    10.12.2000
        *
        */
    public String drawForm( HttpServletRequest request,
                    HttpServletResponse response,
                    ParamBean jParams )
    {
            String html = "";
            String entries = loadEntries( request, jParams );
            String commentField = "<textarea name=\"gb_comment\" rows=\"3\" cols=\"25\" wrap=\"soft\"></textarea>\n";
            String authorField = "<input type=\"text\" name=\"gb_author\" size=\"20\" maxlength=\"200\">\n";
            String submitField = "<input type=\"submit\" value=\"Add Entry\">\n";
            String filePath = jParams.settings().getComponentsDiskPath() + TEMPLATE_PATH + TEMPLATE_FILE;

            String actionURL;
            if (request.getContextPath().equals("/")) {
                actionURL = request.getServletPath();
            } else {
            actionURL = request.getContextPath() + request.getServletPath();
            }

            String flushField = "";
            if (jParams.getOperationMode() == jParams.EDIT) {
                int matrix = (int)(Math.random() * 10000);
                flushField += "<input type=\"button\" name=\"flush\" value=\"Flush Entries\" ";
                flushField += "onClick=\"location.href='" + response.encodeURL(actionURL + "?gb_flush=true&matrix=" + matrix ) + "'\">\n";
            }

            Hashtable tokens = new Hashtable();
            tokens.put( "entries", entries );
            tokens.put( "commentField", commentField );
            tokens.put( "authorField", authorField );
            tokens.put( "submitField", submitField );
            tokens.put( "flushField", flushField );

            html = "<form method=\"POST\" action=\"" + response.encodeURL(actionURL) + "\">\n";
            html += composeSource(  filePath, tokens );
            html += "</form>\n";
            return html;
    } // end drawForm



    /***
        * composeSource
        * EV    10.12.2000
        *
        */
    public String composeSource( String filePath, Hashtable tokens )
    {
        String contents = "";
        try {
            contents = FileUtils.getInstance().readFile( filePath );
        } catch (Exception e) {
            //System.out.println( "GuestBookApp > Error occured : " + e );
            contents = "- Error in reading template file - ";
            return contents;
        }

        int pos = 0;
        String theKey = "";
        Enumeration keys = tokens.keys();
        while (keys.hasMoreElements()) {
            theKey = (String) keys.nextElement();
            pos = contents.indexOf( "<!--" + theKey + "-->" );
            if (pos > -1) {
                contents = contents.substring( 0, pos )
                            + tokens.get(theKey)
                            + contents.substring( pos, contents.length() );
            }
        }

        return contents;
    } // end composeSource



} // end GuestBookApp