OpenNMS API 1.2.3

org.opennms.web.graph
Class RRDAdHocGraphServlet

java.lang.Object
  extended byjavax.servlet.GenericServlet
      extended byjavax.servlet.http.HttpServlet
          extended byorg.opennms.web.graph.RRDAdHocGraphServlet
All Implemented Interfaces:
java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public class RRDAdHocGraphServlet
extends javax.servlet.http.HttpServlet

A servlet that creates a custom graph of network performance data using the RRDTool .

This servlet executes an rrdtool graph command in another process, piping its PNG file to standard out. The servlet then reads that PNG file and returns it on the ServletOutputStream.

Author:
Lawrence Karnowski , OpenNMS
See Also:
Serialized Form

Field Summary
protected  java.lang.String commandPrefix
          The prefix for the RRDtool command (including the executable's pathname) as specified in the rrdtool-graph properties file.
protected  java.lang.String mimeType
          The mime type of the image we will return.
protected  java.util.Properties properties
          Holds the information specified in the rrdtool-graph properties file.
protected  java.io.File workDir
          The working directory as specifed in the rrdtool-graph properties file.
 
Fields inherited from class javax.servlet.http.HttpServlet
 
Fields inherited from class javax.servlet.GenericServlet
 
Constructor Summary
RRDAdHocGraphServlet()
           
 
Method Summary
protected  java.lang.String createAdHocCommand(javax.servlet.http.HttpServletRequest request, java.lang.String rrdDir, java.lang.String start, java.lang.String end)
           
 void doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
          Checks the parameters passed to this servlet, and if all are okay, executes the RRDTool command in another process and pipes its PNG output to the ServletOutputStream back to the requesting web browser.
 void init()
          Initializes this servlet by reading the rrdtool-graph properties file.
 
Methods inherited from class javax.servlet.http.HttpServlet
doDelete, doHead, doOptions, doPost, 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

workDir

protected java.io.File workDir
The working directory as specifed in the rrdtool-graph properties file.


commandPrefix

protected java.lang.String commandPrefix
The prefix for the RRDtool command (including the executable's pathname) as specified in the rrdtool-graph properties file.


mimeType

protected java.lang.String mimeType
The mime type of the image we will return.


properties

protected java.util.Properties properties
Holds the information specified in the rrdtool-graph properties file.

Constructor Detail

RRDAdHocGraphServlet

public RRDAdHocGraphServlet()
Method Detail

init

public void init()
          throws javax.servlet.ServletException
Initializes this servlet by reading the rrdtool-graph properties file.

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
Checks the parameters passed to this servlet, and if all are okay, executes the RRDTool command in another process and pipes its PNG output to the ServletOutputStream back to the requesting web browser.

Throws:
javax.servlet.ServletException
java.io.IOException

createAdHocCommand

protected java.lang.String createAdHocCommand(javax.servlet.http.HttpServletRequest request,
                                              java.lang.String rrdDir,
                                              java.lang.String start,
                                              java.lang.String end)

OpenNMS API 1.2.3

Generated by eevans on May 29 2005 2015.