bradleyross.j2ee.servlets

Class Servlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

bradleyross.j2ee.servlets.Servlet

All Implemented Interfaces:

Serializable, Servlet, ServletConfig

Direct Known Subclasses:

DownloadItem, EchoBack

public abstract class Servlet
extends HttpServlet

Superclass for servlets.

Author:

Bradley Ross

See Also:

ServletHelpers, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	Servlet.ThisPage This class is placed here so that the programmer can subclass either Servlet.ThisPage or bradleyross.library.servlets.ThisPage.

Field Summary

Fields

Modifier and Type	Field and Description
private ServletConfig	config Information on the configuration of the servlet.
private static long	serialVersionUID Added to satisfy Serializable interface.

Constructor Summary

Constructors

Constructor and Description
Servlet() Inserted for debugging;

Method Summary

Methods

Modifier and Type	Method and Description
protected Date	buildDate(int year, int month, int day) Construct an SQL date using the year, month, and day
protected Date	buildDate(String yearValue, String monthValue, String dayValue) Construct an SQL date using the year, month, and day
static String	buildEscapeDate(Date date) Generate an SQL escape date.
static String	buildEscapeDate(int year, int month, int day) Build a date in the java.sql.Date escape format.
static String	buildEscapeDate(int year, int month, int day, String defaultDate) Build a date in the java.sql.Date escape format.
static String	buildEscapeDate(String year, String month, String day) Build a date in the java.sql.Date escape format.
static String	buildEscapeDate(String year, String month, String day, String defaultDate) Build a date in the java.sql.Date escape format.
void	ender(Servlet.ThisPage thisPage) Processing after calling processor method.
ServletConfig	getConfig() Obtains servlet configuration information.
static String	getString(ResultSet rs, String name) Returns the string for a non-breaking space if a string column in a table is null or blank, otherwise returns an escaped string.
static String	getTextareaValue(ResultSet rs, String name) Obtains a value from a result set for use as the starting value of a Textarea element.
static String	getTextValue(ResultSet rs, String name) Obtains a value from a result set for use as the value attribute of a input element of type text.
void	init(ServletConfig configValue) Called when initializing the object for handling HTTP transactions.
protected static void	innerTest(String value) Internal debugging aid for checking parseEscapeDate.
protected void	loadChar(PreparedStatement stmt, int location, String value) Utility method for setting parameters in Prepared Statements.
protected void	loadVarchar(PreparedStatement stmt, int location, String value) Utility method for setting parameters in Prepared Statements.
static void	main(String[] args) This was inserted for testing of some of the internal static methods and is only for debugging purposes.
static String	matchValues(String value1, String value2) Utility to aid in creating option lists for pull-down menus.
static String[]	parseEscapeDate(String escapeDate) Break a java.sql.Date escape format date into a set of string objects for the year, month, and day portions.
protected abstract void	processor(Servlet.ThisPage thisPage) Class specific processing for this class.
void	service(HttpServletRequest requestValue, HttpServletResponse responseValue) Carries out processing for a HTTP transaction.
protected void	setDateRange(Servlet.ThisPage instance) Obtain date range from HTTP request.
void	starter(Servlet.ThisPage thisPage) Processing before calling processor method.

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, 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

serialVersionUID

private static final long serialVersionUID

Added to satisfy Serializable interface.

See Also:

Serializable, Constant Field Values

config

private ServletConfig config

Information on the configuration of the servlet.

This is used to pass information from the init(ServletConfig) method to the other methods in the class.

Constructor Detail

Servlet

public Servlet()

Inserted for debugging;

Method Detail

init

public void init(ServletConfig configValue)
          throws ServletException

Called when initializing the object for handling HTTP transactions.

Specified by:

init in interface Servlet

Overrides:

init in class GenericServlet

Parameters:

configValue - Servlet configuration object

Throws:

ServletException

getConfig

public ServletConfig getConfig()

Obtains servlet configuration information.

Returns:

servlet configuration object

service

public void service(HttpServletRequest requestValue,
           HttpServletResponse responseValue)
             throws IOException

Carries out processing for a HTTP transaction.

Overrides:

service in class HttpServlet

Parameters:

requestValue - Request object

responseValue - Response object

Throws:

IOException

See Also:

starter(ThisPage), processor(ThisPage), ender(ThisPage)

starter

public void starter(Servlet.ThisPage thisPage)
             throws IOException

Processing before calling processor method.

This method can be overridden in subclasses to provide a class that carries out the desired operation for a group of classes.

Parameters:

thisPage - Information on this HTTP transaction

Throws:

IOException

See Also:

processor(ThisPage)

ender

public void ender(Servlet.ThisPage thisPage)
           throws IOException

Processing after calling processor method.

This method can be overridden in subclasses to provide a class that carries out the desired operation for a group of classes.

Parameters:

thisPage - Information on this HTTP transaction

Throws:

IOException

See Also:

processor(ThisPage)

processor

protected abstract void processor(Servlet.ThisPage thisPage)
                           throws IOException

Class specific processing for this class.

Parameters:

thisPage - Information on this HTTP transaction

Throws:

IOException

buildDate

protected Date buildDate(String yearValue,
             String monthValue,
             String dayValue)

Construct an SQL date using the year, month, and day

Parameters:

yearValue - Year (4 digit)

monthValue - Number of Month (January = 1)

dayValue - Day of month

Returns:

SQL date

buildDate

protected Date buildDate(int year,
             int month,
             int day)

Construct an SQL date using the year, month, and day

Parameters:

year - Year (4 digit)

month - Number of month (January = 1)

day - Day of month

Returns:

SQL date

setDateRange

protected void setDateRange(Servlet.ThisPage instance)

Obtain date range from HTTP request.

Parameters:

instance - Object containing information for this HTTP request

See Also:

Date

buildEscapeDate

public static String buildEscapeDate(int year,
                     int month,
                     int day)
                              throws IOException

Build a date in the java.sql.Date escape format.

Parameters:

year - Year as an integer

month - Month as an integer from 1 to 12

day - Day of month as an integer from 1 to 31

Returns:

Date in escape format

Throws:

SQLException

IOException

See Also:

It appears that SQL Server is unable to handle dates before the year 1900.

buildEscapeDate

public static String buildEscapeDate(String year,
                     String month,
                     String day)
                              throws IOException

Build a date in the java.sql.Date escape format.

Parameters:

year - String containing the year as an integer

month - String containing the month as an integer from 1 to 12

day - String containing the day of month as an integer from 1 to 31

Returns:

Date in escape format

Throws:

IOException

See Also:

Date.toString()

buildEscapeDate

public static String buildEscapeDate(Date date)

Generate an SQL escape date.

Parameters:

date - SQL date

Returns:

SQL escape date

buildEscapeDate

public static String buildEscapeDate(int year,
                     int month,
                     int day,
                     String defaultDate)
                              throws IOException

Build a date in the java.sql.Date escape format.

Parameters:

year - Year as an integer

month - Month as an integer from 1 to 12

day - Day of month as an integer from 1 to 31

defaultDate - Date to use if error in processing

Returns:

Date in escape format

Throws:

SQLException

IOException

See Also:

It appears that SQL Server is unable to handle dates before the year 1900.

buildEscapeDate

public static String buildEscapeDate(String year,
                     String month,
                     String day,
                     String defaultDate)
                              throws IOException

Build a date in the java.sql.Date escape format.

Parameters:

year - String containing the year as an integer

month - String containing the month as an integer from 1 to 12

day - String containing the day of month as an integer from 1 to 31

defaultDate - Date to use if error in processing

Returns:

Date in escape format

Throws:

IOException

See Also:

Date.toString()

parseEscapeDate

public static String[] parseEscapeDate(String escapeDate)

Break a java.sql.Date escape format date into a set of string objects for the year, month, and day portions.

Parameters:

escapeDate - Date to be parsed

Returns:

Array of strings

See Also:

Date.toString()

loadChar

protected void loadChar(PreparedStatement stmt,
            int location,
            String value)
                 throws SQLException

Utility method for setting parameters in Prepared Statements.

For CHAR data types.

Parameters:

stmt - PreparedStatement object

location - Number of parameter

value - Value to be loaded in parameter

Throws:

SQLException

loadVarchar

protected void loadVarchar(PreparedStatement stmt,
               int location,
               String value)
                    throws SQLException

Utility method for setting parameters in Prepared Statements.

For VARCHAR data types.

Parameters:

stmt - PreparedStatement object

location - Number of parameter

value - Value to be loaded in parameter

Throws:

SQLException

matchValues

public static String matchValues(String value1,
                 String value2)

Utility to aid in creating option lists for pull-down menus.

Parameters:

value1 - First string to be compared

value2 - Second string to be compared

Returns:

The word SELECTED if the two strings match, otherwise a blank.

getTextValue

public static String getTextValue(ResultSet rs,
                  String name)

Obtains a value from a result set for use as the value attribute of a input element of type text.

Parameters:

rs - Result set

name - Name of column in result set

Returns:

Text string for value attribute.

getTextareaValue

public static String getTextareaValue(ResultSet rs,
                      String name)

Obtains a value from a result set for use as the starting value of a Textarea element.

Parameters:

rs - Result set

name - Name of column in result set

Returns:

Text string for Textarea tag.

See Also:

StringHelpers.escapeHTML(String, String)

getString

public static String getString(ResultSet rs,
               String name)

Returns the string for a non-breaking space if a string column in a table is null or blank, otherwise returns an escaped string.

Parameters:

rs - Result set containing value

name - Name of column

Returns:

Processed string for insertion in web page

innerTest

protected static void innerTest(String value)

Internal debugging aid for checking parseEscapeDate.

Parameters:

value - String to be parsed

See Also:

parseEscapeDate(String)

main

public static void main(String[] args)

This was inserted for testing of some of the internal static methods and is only for debugging purposes.

Parameters:

args - Not used