de.laures.cewolf
Class CewolfRenderer
java.lang.Object
javax.servlet.GenericServlet
javax.servlet.http.HttpServlet
de.laures.cewolf.CewolfRenderer
- All Implemented Interfaces:
- WebConstants, java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig
public class CewolfRenderer
- extends javax.servlet.http.HttpServlet
- implements WebConstants
The rendering servlet of Cewolf. It is resposible for writing an entire chart
img into the response stream of the client. Everything needed for this is
prepared already by the ChartImgTag resp. LegendTag. The ID of a chart image
is passed to this servlet as a request parameter. After that the image object
is retrieved from the server side session based image cache. This servlet
must be configured in web.xml of the web application in order to use Cewolf
services. The servlet's URL relative to the web apps root is used as the
renderer attribute of the ChartImgTag resp. LegendTag in the JSP page.
- Since:
- 0.1
- Author:
- Guido Laures
- See Also:
ChartImgTag
,
LegendTag
,
Serialized Form
Method Summary |
private void |
addHeaders(javax.servlet.http.HttpServletResponse response)
Method addHeaders. |
protected void |
doGet(javax.servlet.http.HttpServletRequest request,
javax.servlet.http.HttpServletResponse response)
|
void |
init(javax.servlet.ServletConfig servletCfg)
|
private void |
logAndRenderException(java.lang.Throwable ex,
javax.servlet.http.HttpServletResponse response,
int width,
int height)
|
private void |
logRequest(javax.servlet.http.HttpServletRequest request)
|
void |
printParameters(javax.servlet.http.HttpServletRequest request)
Processes HTTP GET request. |
private void |
renderImageExpiry(javax.servlet.http.HttpServletResponse response,
int width,
int height)
Method renderImageExpiry. |
private void |
requestState(javax.servlet.http.HttpServletResponse response)
Method requestState. |
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 |
INIT_CONFIG
public static final java.lang.String INIT_CONFIG
- See Also:
- Constant Field Values
STATE
private static final java.lang.String STATE
- See Also:
- Constant Field Values
debugged
private boolean debugged
requestCount
private int requestCount
lock
private java.lang.Byte lock
config
private Configuration config
CewolfRenderer
public CewolfRenderer()
init
public void init(javax.servlet.ServletConfig servletCfg)
throws javax.servlet.ServletException
- Specified by:
init
in interface javax.servlet.Servlet
- Overrides:
init
in class javax.servlet.GenericServlet
- Throws:
javax.servlet.ServletException
printParameters
public void printParameters(javax.servlet.http.HttpServletRequest request)
- Processes HTTP
GET
request. Renders the chart or the lengend
into the client's response stream.
- Parameters:
request
- servlet requestresponse
- servlet response
- Throws:
javax.servlet.ServletException
- when the production of data could not be handled by the
configured DatasetProcuder
doGet
protected void doGet(javax.servlet.http.HttpServletRequest request,
javax.servlet.http.HttpServletResponse response)
throws javax.servlet.ServletException,
java.io.IOException
- Overrides:
doGet
in class javax.servlet.http.HttpServlet
- Throws:
javax.servlet.ServletException
java.io.IOException
addHeaders
private void addHeaders(javax.servlet.http.HttpServletResponse response)
- Method addHeaders.
- Parameters:
response
-
requestState
private void requestState(javax.servlet.http.HttpServletResponse response)
throws java.io.IOException
- Method requestState.
- Parameters:
request
- response
-
- Throws:
java.io.IOException
logAndRenderException
private void logAndRenderException(java.lang.Throwable ex,
javax.servlet.http.HttpServletResponse response,
int width,
int height)
throws java.io.IOException
- Throws:
java.io.IOException
renderImageExpiry
private void renderImageExpiry(javax.servlet.http.HttpServletResponse response,
int width,
int height)
throws java.io.IOException
- Method renderImageExpiry.
- Parameters:
response
- width
- height
-
- Throws:
java.io.IOException
logRequest
private void logRequest(javax.servlet.http.HttpServletRequest request)
throws java.io.IOException
- Throws:
java.io.IOException