public ProcessEnvironment(HttpServletRequest req,
    ServletContext context) 
{
                                                                                       
        this(req, context, 0);
}

Creates a ProcessEnvironment and derives the necessary environment, working directory, command, etc.

Parameters:

req - HttpServletRequest for information provided by the Servlet API

context - ServletContext for information provided by the Servlet API

 public ProcessEnvironment(HttpServletRequest req,
    ServletContext context,
    int debug) 
{
            this.debug = debug;
            setupFromContext(context);
            setupFromRequest(req);
            this.valid = deriveProcessEnvironment(req);
            if (log.isDebugEnabled()) 
                log.debug(this.getClass().getName() + "() ctor, debug level " + 
                          debug);
}

Creates a ProcessEnvironment and derives the necessary environment, working directory, command, etc.

Parameters:

req - HttpServletRequest for information provided by the Servlet API

context - ServletContext for information provided by the Servlet API

debug - int debug level (0 == none, 4 == medium, 6 == lots)

 protected String blanksToString(String couldBeBlank,
    String subForBlanks) 
{
            return (("".equals(couldBeBlank) || couldBeBlank == null) ?
                subForBlanks : couldBeBlank);
}

Converts blank strings to another string

 protected boolean deriveProcessEnvironment(HttpServletRequest req) 
{
        Hashtable envp = new Hashtable();
        command = getCommand();
        if (command != null) {
            workingDirectory = new
                File(command.substring(0,
                command.lastIndexOf(File.separator)));
                envp.put("X_TOMCAT_COMMAND_PATH", command); //for kicks
        }
        this.env = envp;
        return true;
}

Constructs the Process environment to be supplied to the invoked process. Defines an environment no environment variables.

Should be overriden by subclasses to perform useful setup.

 public String getCommand() 
{
        return command;
}

Gets derived command string

 public ServletContext getContext() 
{
            return context;
}

 public String getContextPath() 
{
            return contextPath;
}

 public Hashtable getEnvironment() 
{
        return env;
}

Gets process' environment

 public String getServletPath() 
{
            return servletPath;
}

 public String getWebAppRootDir() 
{
        return webAppRootDir;
}

Gets the root directory of the web application to which this process\ belongs

 public File getWorkingDirectory() 
{
        return workingDirectory;
}

Gets this process' derived working directory

 public boolean isValid() 
{
        return valid;
}

Gets validity status

 protected String nullsToBlanks(String s) 
{
        return nullsToString(s, "");
}

Converts null strings to blank strings ("")

 protected String nullsToString(String couldBeNull,
    String subForNulls) 
{
        return (couldBeNull == null ? subForNulls : couldBeNull);
}

Converts null strings to another string

 protected String setCommand(String command) 
{
        return command;
}

Sets the desired command string

 public Hashtable setEnvironment(Hashtable env) 
{
        this.env = env;
        return this.env;
}

Sets process' environment

 protected  void setupFromContext(ServletContext context) 
{
        this.context = context;
        this.webAppRootDir = context.getRealPath("/");
}

Uses the ServletContext to set some process variables

 protected  void setupFromRequest(HttpServletRequest req) 
{
        this.contextPath = req.getContextPath();
        this.pathInfo = req.getPathInfo();
        this.servletPath = req.getServletPath();
}

Uses the HttpServletRequest to set most process variables

 public String toString() 
{
        StringBuffer sb = new StringBuffer();
        sb.append("< TABLE border=2 >");
        sb.append("< tr >< th colspan=2 bgcolor=grey >");
        sb.append("ProcessEnvironment Info< /th >< /tr >");
        sb.append("< tr >< td >Debug Level< /td >< td >");
        sb.append(debug);
        sb.append("< /td >< /tr >");
        sb.append("< tr >< td >Validity:< /td >< td >");
        sb.append(isValid());
        sb.append("< /td >< /tr >");
        if (isValid()) {
            Enumeration envk = env.keys();
            while (envk.hasMoreElements()) {
                String s = (String)envk.nextElement();
                sb.append("< tr >< td >");
                sb.append(s);
                sb.append("< /td >< td >");
                sb.append(blanksToString((String)env.get(s),
                    "[will be set to blank]"));
                    sb.append("< /td >< /tr >");
            }
        }
        sb.append("< tr >< td colspan=2 >< HR >< /td >< /tr >");
        sb.append("< tr >< td >Derived Command< /td >< td >");
        sb.append(nullsToBlanks(command));
        sb.append("< /td >< /tr >");
        sb.append("< tr >< td >Working Directory< /td >< td >");
        if (workingDirectory != null) {
            sb.append(workingDirectory.toString());
        }
        sb.append("< /td >< /tr >");
        sb.append("< /TABLE >< p >end.");
        return sb.toString();
}

Print important process environment information in an easy-to-read HTML table