org.apache.catalina.servlets

Class CGIServlet.CGIEnvironment

java.lang.Object

org.apache.catalina.servlets.CGIServlet.CGIEnvironment

Enclosing class:

CGIServlet

protected class CGIServlet.CGIEnvironment
extends Object

Encapsulates the CGI environment and rules to derive that environment from the servlet container and request information.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	CGIEnvironment(HttpServletRequest req, ServletContext context) Creates a CGIEnvironment and derives the necessary environment, query parameters, working directory, cgi command, etc.

Method Summary

Modifier and Type	Method and Description
protected String	blanksToString(String couldBeBlank, String subForBlanks) Converts blank strings to another string
protected void	expandCGIScript() Extracts requested resource from web app archive to context work directory to enable CGI script to be executed.
protected String[]	findCGI(String pathInfo, String webAppRootDir, String contextPath, String servletPath, String cgiPathPrefix) Resolves core information about the cgi script.
protected String	getCommand() Gets derived command string
protected Hashtable<String,String>	getEnvironment() Gets derived CGI environment
protected ArrayList<String>	getParameters() Gets derived CGI query parameters
protected File	getWorkingDirectory() Gets derived CGI working directory
protected boolean	isValid() Gets validity status
protected String	nullsToBlanks(String s) Converts null strings to blank strings ("")
protected String	nullsToString(String couldBeNull, String subForNulls) Converts null strings to another string
protected boolean	setCGIEnvironment(HttpServletRequest req) Constructs the CGI environment to be supplied to the invoked CGI script; relies heavily on Servlet API methods and findCGI
protected void	setupFromContext(ServletContext context) Uses the ServletContext to set some CGI variables
protected void	setupFromRequest(HttpServletRequest req) Uses the HttpServletRequest to set most CGI variables
String	toString() Print important CGI environment information in a easy-to-read HTML table

Methods inherited from class java.lang.Object

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

Constructor Detail

CGIEnvironment

protected CGIEnvironment(HttpServletRequest req,
                         ServletContext context)
                  throws IOException

Creates a CGIEnvironment and derives the necessary environment, query parameters, working directory, cgi command, etc.

Parameters:

req - HttpServletRequest for information provided by the Servlet API

context - ServletContext for information provided by the Servlet API

Throws:

IOException - an IO error occurred

Method Detail

setupFromContext

protected void setupFromContext(ServletContext context)

Uses the ServletContext to set some CGI variables

Parameters:

context - ServletContext for information provided by the Servlet API

setupFromRequest

protected void setupFromRequest(HttpServletRequest req)
                         throws UnsupportedEncodingException

Uses the HttpServletRequest to set most CGI variables

Parameters:

req - HttpServletRequest for information provided by the Servlet API

Throws:

UnsupportedEncodingException - Unknown encoding

findCGI

protected String[] findCGI(String pathInfo,
                           String webAppRootDir,
                           String contextPath,
                           String servletPath,
                           String cgiPathPrefix)

Resolves core information about the cgi script.

Example URI:

 /servlet/cgigateway/dir1/realCGIscript/pathinfo1 

• path = $CATALINA_HOME/mywebapp/dir1/realCGIscript
• scriptName = /servlet/cgigateway/dir1/realCGIscript
• cgiName = /dir1/realCGIscript
• name = realCGIscript

CGI search algorithm: search the real path below <my-webapp-root> and find the first non-directory in the getPathTranslated("/"), reading/searching from left-to-right.

The CGI search path will start at webAppRootDir + File.separator + cgiPathPrefix (or webAppRootDir alone if cgiPathPrefix is null).

cgiPathPrefix is defined by setting this servlet's cgiPathPrefix init parameter

Parameters:

pathInfo - String from HttpServletRequest.getPathInfo()

webAppRootDir - String from context.getRealPath("/")

contextPath - String as from HttpServletRequest.getContextPath()

servletPath - String as from HttpServletRequest.getServletPath()

cgiPathPrefix - subdirectory of webAppRootDir below which the web app's CGIs may be stored; can be null. The CGI search path will start at webAppRootDir + File.separator + cgiPathPrefix (or webAppRootDir alone if cgiPathPrefix is null). cgiPathPrefix is defined by setting the servlet's cgiPathPrefix init parameter.

Returns:

• path - full file-system path to valid cgi script, or null if no cgi was found
• scriptName - CGI variable SCRIPT_NAME; the full URL path to valid cgi script or null if no cgi was found
• cgiName - servlet pathInfo fragment corresponding to the cgi script itself, or null if not found
• name - simple name (no directories) of the cgi script, or null if no cgi was found

setCGIEnvironment

protected boolean setCGIEnvironment(HttpServletRequest req)
                             throws IOException

Constructs the CGI environment to be supplied to the invoked CGI script; relies heavily on Servlet API methods and findCGI

Parameters:

req - request associated with the CGI Invocation

Returns:

true if environment was set OK, false if there was a problem and no environment was set

Throws:

IOException - an IO error occurred

expandCGIScript

protected void expandCGIScript()

Extracts requested resource from web app archive to context work directory to enable CGI script to be executed.

toString

public String toString()

Print important CGI environment information in a easy-to-read HTML table

Overrides:

toString in class Object

Returns:

HTML string containing CGI environment info

getCommand

protected String getCommand()

Gets derived command string

Returns:

command string

getWorkingDirectory

protected File getWorkingDirectory()

Gets derived CGI working directory

Returns:

working directory

getEnvironment

protected Hashtable<String,String> getEnvironment()

Gets derived CGI environment

Returns:

CGI environment

getParameters

protected ArrayList<String> getParameters()

Gets derived CGI query parameters

Returns:

CGI query parameters

isValid

protected boolean isValid()

Gets validity status

Returns:

true if this environment is valid, false otherwise

nullsToBlanks

protected String nullsToBlanks(String s)

Converts null strings to blank strings ("")

Parameters:

s - string to be converted if necessary

Returns:

a non-null string, either the original or the empty string ("") if the original was null

nullsToString

protected String nullsToString(String couldBeNull,
                               String subForNulls)

Converts null strings to another string

Parameters:

couldBeNull - string to be converted if necessary

subForNulls - string to return instead of a null string

Returns:

a non-null string, either the original or the substitute string if the original was null

blanksToString

protected String blanksToString(String couldBeBlank,
                                String subForBlanks)

Converts blank strings to another string

Parameters:

couldBeBlank - string to be converted if necessary

subForBlanks - string to return instead of a blank string

Returns:

a non-null string, either the original or the substitute string if the original was null or empty ("")