org.apache.derby.drda
Class NetServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.apache.derby.drda.NetServlet

All Implemented Interfaces:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public class NetServlet
extends javax.servlet.http.HttpServlet

This servlet can be used to start Derby Network Server from a remote location.

These servlet configuration parameters are understood by this servlet.

• portNumber

  - Port number to use. The default is 1527.

• startNetworkServerOnInit

  - Starts the Derby Network Server at servlet initialization if 'true'.

• tracingDirectory

  - Directory for trace files

See Also:

Serialized Form

Field Summary

private java.lang.String	host
private static int	INVALID
private static java.lang.String[]	knownLang
private boolean	logStatus
private static int	MAX_CONNECT_TRYS
private static int	NOT_GIVEN
private int	portNumber
private NetworkServerControl	server
private static java.lang.String	SERVLET_ADDRESS
private static java.lang.String	SERVLET_PROP_MESSAGES
private boolean	traceStatus
private java.lang.String	tracingDirectory

Constructor Summary

NetServlet()

Method Summary

private void	displayCurrentStatus(LocalizedResource localUtil, java.lang.String returnMessage, java.io.PrintWriter out) Display the current Network server status
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Get the form of NetServlet.
void	doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Get the form of NetServlet.
private java.lang.String	escapeHTML(java.lang.String str) Escapes potentially dangerous characters in data written to the browser.
private java.lang.String	escapeSingleQuotes(java.lang.String str) If the received string has one or more single quotes in it, replace each one with the HTML escape-code for a single quote (apostrophe) so that the string can be properly displayed on a submit button.
private java.lang.String	fixLanguageCode(java.lang.String lang) Fix the language code, as some browsers send then in a bad format (for instance, Firefox sends en-us instead of en_US).
private java.lang.String	fixLanguageCode(java.lang.String lang, int index)
private LocalizedResource	getCurrentAppUI(javax.servlet.http.HttpServletRequest request, java.lang.String[] locale) Determine the locale file needed for this browsers preferences Defaults to the settings for derby.locale and derby.codeset if set English otherwise if browsers preferences can't be found
private java.lang.String	getDoAction(javax.servlet.http.HttpServletRequest request)
private java.lang.String	getForm(javax.servlet.http.HttpServletRequest request)
private java.lang.String	getHtmlLabelledMessageInstance(LocalizedResource localUtil, java.lang.String key, java.lang.String id) get an HTML labelled message from the resource bundle file, according to the given key.
private int	getIntParameter(javax.servlet.http.HttpServletRequest request, java.lang.String name, java.lang.String fieldKey, LocalizedResource localUtil, java.lang.String returnMessage, java.io.PrintWriter out) Get an integer parameter
private java.lang.String	getLocStringFromLanguage(java.lang.String lang) Get locale string from language which may have qvalue set
private java.lang.String	getLogging(javax.servlet.http.HttpServletRequest request)
private java.lang.String	getParam(javax.servlet.http.HttpServletRequest request, java.lang.String paramName) get UTF8 parameter value and decode international characters
private boolean	getServerStatus() Get the currrent server status by using test connection
private java.lang.String	getTrace(javax.servlet.http.HttpServletRequest request)
void	init(javax.servlet.ServletConfig config) Initialize the servlet.
private static boolean	isServerStarted(NetworkServerControl server, int ntries)
private boolean	logging(LocalizedResource localUtil, boolean val, java.lang.String returnMessage, java.io.PrintWriter out) Turn logging of connections on
private void	printAsContentHeader(java.lang.String str, java.io.PrintWriter out) Print the received string as a header.
private void	printBanner(LocalizedResource localUtil, java.io.PrintWriter out) Print Derby Network Server banner
private void	printErrorForm(LocalizedResource localUtil, java.lang.Exception e, java.lang.String returnMessage, java.io.PrintWriter out) Display an error form
private void	printErrorForm(LocalizedResource localUtil, java.lang.String msg, java.lang.String returnMessage, java.io.PrintWriter out) Display an error form
private void	runServer(LocalizedResource localUtil, java.lang.String returnMessage, java.io.PrintWriter out) Start the network server and attempt to connect to it before returning
private void	setDefaults() Set defaults for logging and tracing (both off)
private boolean	setNetParam(LocalizedResource localUtil, int max, int slice, java.lang.String returnMessage, java.io.PrintWriter out) Set Network server parameters
private boolean	shutdownServer(LocalizedResource localUtil, java.lang.String returnMessage, java.io.PrintWriter out) Shutdown the network server
private boolean	traceAll(LocalizedResource localUtil, boolean val, java.lang.String returnMessage, java.io.PrintWriter out) Change tracing for all sessions
private boolean	traceDirectory(LocalizedResource localUtil, java.lang.String traceDirectory, java.lang.String returnMessage, java.io.PrintWriter out) Set trace directory
private boolean	traceSession(LocalizedResource localUtil, boolean val, int session, java.lang.String returnMessage, java.io.PrintWriter out) Change tracing for a given session
private int	translationAvailable(java.lang.String lang) Check if the required translation is available

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAX_CONNECT_TRYS

private static final int MAX_CONNECT_TRYS

See Also:

Constant Field Values

SERVLET_PROP_MESSAGES

private static final java.lang.String SERVLET_PROP_MESSAGES

See Also:

Constant Field Values

SERVLET_ADDRESS

private static final java.lang.String SERVLET_ADDRESS

See Also:

Constant Field Values

knownLang

private static final java.lang.String[] knownLang

host

private java.lang.String host

portNumber

private int portNumber

tracingDirectory

private volatile java.lang.String tracingDirectory

logStatus

private volatile boolean logStatus

traceStatus

private volatile boolean traceStatus

NOT_GIVEN

private static final int NOT_GIVEN

See Also:

Constant Field Values

INVALID

private static final int INVALID

See Also:

Constant Field Values

server

private NetworkServerControl server

Constructor Detail

NetServlet

public NetServlet()

Method Detail

init

public void init(javax.servlet.ServletConfig config)
          throws javax.servlet.ServletException

Initialize the servlet. Configuration parameters:

• portNumber

  - Port number

• host

  - Host name

• traceDirectory

  - location of trace directory

• startNetworkServerOnInit

  - start the server on initialization

Specified by:

init in interface javax.servlet.Servlet

Overrides:

init in class javax.servlet.GenericServlet

Throws:

javax.servlet.ServletException

doGet

public void doGet(javax.servlet.http.HttpServletRequest request,
                  javax.servlet.http.HttpServletResponse response)
           throws javax.servlet.ServletException,
                  java.io.IOException

Get the form of NetServlet. Provides buttons and forms to control the Network server.

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

java.io.IOException

doPost

public void doPost(javax.servlet.http.HttpServletRequest request,
                   javax.servlet.http.HttpServletResponse response)
            throws javax.servlet.ServletException,
                   java.io.IOException

Get the form of NetServlet. Provides a buttons and form to control the Network server

Overrides:

doPost in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

java.io.IOException

getForm

private java.lang.String getForm(javax.servlet.http.HttpServletRequest request)
                          throws java.io.IOException

Throws:

java.io.IOException

getDoAction

private java.lang.String getDoAction(javax.servlet.http.HttpServletRequest request)
                              throws java.io.IOException

Throws:

java.io.IOException

getLogging

private java.lang.String getLogging(javax.servlet.http.HttpServletRequest request)
                             throws java.io.IOException

Throws:

java.io.IOException

getTrace

private java.lang.String getTrace(javax.servlet.http.HttpServletRequest request)
                           throws java.io.IOException

Throws:

java.io.IOException

getParam

private java.lang.String getParam(javax.servlet.http.HttpServletRequest request,
                                  java.lang.String paramName)
                           throws java.io.IOException

get UTF8 parameter value and decode international characters

Parameters:

request - HttpServletRequest

paramName - Parameter name

Returns:

decoded String

Throws:

java.io.IOException

runServer

private void runServer(LocalizedResource localUtil,
                       java.lang.String returnMessage,
                       java.io.PrintWriter out)
                throws javax.servlet.ServletException

Start the network server and attempt to connect to it before returning

Parameters:

localUtil - LocalizedResource to use to translate messages

returnMessage - localized continue message for continue button on error form

out - Form PrintWriter

Throws:

javax.servlet.ServletException - throws an exception if error in starting the Network Server during initialization

printErrorForm

private void printErrorForm(LocalizedResource localUtil,
                            java.lang.Exception e,
                            java.lang.String returnMessage,
                            java.io.PrintWriter out)

Display an error form

Parameters:

localUtil - LocalizedResource to use to translate messages

e - Exception to be displayed

returnMessage - localized continue message for continue button on error form

out - Form PrintWriter

printErrorForm

private void printErrorForm(LocalizedResource localUtil,
                            java.lang.String msg,
                            java.lang.String returnMessage,
                            java.io.PrintWriter out)

Display an error form

Parameters:

localUtil - LocalizedResource to use to translate messages

msg - String to be displayed

out - Form PrintWriter

returnMessage - localized continue message for continue button on error form

displayCurrentStatus

private void displayCurrentStatus(LocalizedResource localUtil,
                                  java.lang.String returnMessage,
                                  java.io.PrintWriter out)

Display the current Network server status

Parameters:

localUtil - LocalizedResource to use for localizing messages

returnMessage - localized continue message for continue button on error form

out - Form PrintWriter

getServerStatus

private boolean getServerStatus()

Get the currrent server status by using test connection

Returns:

true if server is up and reachable; false; otherwise

shutdownServer

private boolean shutdownServer(LocalizedResource localUtil,
                               java.lang.String returnMessage,
                               java.io.PrintWriter out)

Shutdown the network server

Parameters:

localUtil - LocalizedResource to use to translate messages

returnMessage - localized continue message for continue button on error form

out - Form PrintWriter

Returns:

true if succeeded; false; otherwise

logging

private boolean logging(LocalizedResource localUtil,
                        boolean val,
                        java.lang.String returnMessage,
                        java.io.PrintWriter out)

Turn logging of connections on

Parameters:

localUtil - LocalizedResource to use to translate messages

returnMessage - localized continue message for continue button on error form

out - Form PrintWriter

Returns:

true if succeeded; false; otherwise

traceAll

private boolean traceAll(LocalizedResource localUtil,
                         boolean val,
                         java.lang.String returnMessage,
                         java.io.PrintWriter out)

Change tracing for all sessions

Parameters:

localUtil - LocalizedResource to use to translate messages

val - if true, turn tracing on, if false turn it off

returnMessage - localized continue message for continue button on error form

out - Form PrintWriter

Returns:

true if succeeded; false; otherwise

traceSession

private boolean traceSession(LocalizedResource localUtil,
                             boolean val,
                             int session,
                             java.lang.String returnMessage,
                             java.io.PrintWriter out)

Change tracing for a given session

Parameters:

localUtil - LocalizedResource to use to translate messages

val - if true, turn tracing on, if false turn it off

session - session to trace

returnMessage - localized continue message for continue button on error form

out - Form PrintWriter

Returns:

true if succeeded; false; otherwise

traceDirectory

private boolean traceDirectory(LocalizedResource localUtil,
                               java.lang.String traceDirectory,
                               java.lang.String returnMessage,
                               java.io.PrintWriter out)

Set trace directory

Parameters:

localUtil - LocalizedResource to use to translate messages

traceDirectory - directory for trace files

returnMessage - localized continue message for continue button on error form

out - Form PrintWriter

Returns:

true if succeeded; false; otherwise

setNetParam

private boolean setNetParam(LocalizedResource localUtil,
                            int max,
                            int slice,
                            java.lang.String returnMessage,
                            java.io.PrintWriter out)

Set Network server parameters

Parameters:

localUtil - LocalizedResource to use to translate messages

max - maximum number of threads

slice - time slice for each connection

returnMessage - localized continue message for continue button on error form

out - Form PrintWriter

Returns:

true if succeeded; false; otherwise

setDefaults

private void setDefaults()

Set defaults for logging and tracing (both off)

getIntParameter

private int getIntParameter(javax.servlet.http.HttpServletRequest request,
                            java.lang.String name,
                            java.lang.String fieldKey,
                            LocalizedResource localUtil,
                            java.lang.String returnMessage,
                            java.io.PrintWriter out)

Get an integer parameter

Parameters:

request - HttpServetRequest for forms

name - parameter name

fieldKey - Key for the name of the field we're reading.

localUtil - LocalizedResource to use in localizing messages

returnMessage - localized continue message for continue button on error form

out - Form PrintWriter

printBanner

private void printBanner(LocalizedResource localUtil,
                         java.io.PrintWriter out)

Print Derby Network Server banner

getCurrentAppUI

private LocalizedResource getCurrentAppUI(javax.servlet.http.HttpServletRequest request,
                                          java.lang.String[] locale)

Determine the locale file needed for this browsers preferences Defaults to the settings for derby.locale and derby.codeset if set English otherwise if browsers preferences can't be found

Parameters:

request - HttpServetRequest for forms

locale - Name of locale (return arg)

Returns:

the appUI which fits the browsers preferences

getLocStringFromLanguage

private java.lang.String getLocStringFromLanguage(java.lang.String lang)

Get locale string from language which may have qvalue set

Parameters:

lang - language string to parse

Returns:

stripped language string to use in matching

translationAvailable

private int translationAvailable(java.lang.String lang)

Check if the required translation is available

Parameters:

lang - language we are looking for

Returns:

index into language array if found, -1 otherwise;

fixLanguageCode

private java.lang.String fixLanguageCode(java.lang.String lang)

Fix the language code, as some browsers send then in a bad format (for instance, Firefox sends en-us instead of en_US).

Parameters:

lang - language to be fixed

Returns:

fixed version of the language, with _ separating parts and country in upper case

fixLanguageCode

private java.lang.String fixLanguageCode(java.lang.String lang,
                                         int index)

getHtmlLabelledMessageInstance

private java.lang.String getHtmlLabelledMessageInstance(LocalizedResource localUtil,
                                                        java.lang.String key,
                                                        java.lang.String id)

get an HTML labelled message from the resource bundle file, according to the given key.

printAsContentHeader

private void printAsContentHeader(java.lang.String str,
                                  java.io.PrintWriter out)

Print the received string as a header.

Parameters:

str - The string to be printed as a header.

out - Form PrintWriter

escapeSingleQuotes

private java.lang.String escapeSingleQuotes(java.lang.String str)

If the received string has one or more single quotes in it, replace each one with the HTML escape-code for a single quote (apostrophe) so that the string can be properly displayed on a submit button.

Parameters:

str - The string in which we want to escape single quotes.

escapeHTML

private java.lang.String escapeHTML(java.lang.String str)

Escapes potentially dangerous characters in data written to the browser.

NOTE: This is a poor mans implementation - it doesn't protect against all kinds of attacks, and it cannot be used in all contexts.

Parameters:

str - the string to escape

Returns:

A sanitized string.

isServerStarted

private static boolean isServerStarted(NetworkServerControl server,
                                       int ntries)