org.rhq.enterprise.gui.common.servlet
Class ChartServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.rhq.enterprise.gui.common.servlet.ParameterizedServlet
              org.rhq.enterprise.gui.common.servlet.ImageServlet
                  org.rhq.enterprise.gui.common.servlet.ChartServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

Direct Known Subclasses:

AvailabilityStoplightChartServlet, HighLowChartServlet, PerformanceChartServlet, VerticalChartServlet

public abstract class ChartServlet
extends ImageServlet

This servlet returns a response that contains the binary data of an image (JPEG or PNG) that can be viewed in a web browser.

The chart servlet takes the following parameters (any applicable defaults are in bold and required parameters are in italics):

key	value
measurementUnits	<MeasurementUnits.NONE>
showPeak	(false | true)
showHighRange	(false | true)
showValues	(false | true)
showAverage	(false | true)
showLowRange	(false | true)
showLow	(false | true)
showBaseline	(false | true)
baseline*	<double>
highRange*	<double>
lowRange*	<double>

* only used and required if corresponding showXXX parameter is true

See Also:

Serialized Form

Field Summary

static String	BASELINE_PARAM Request parameter for baseline.
static String	HIGHRANGE_PARAM Request parameter for baseline.
static int	IMAGE_HEIGHT_DEFAULT Default image height.
static int	IMAGE_WIDTH_DEFAULT Default image width.
static String	LOWRANGE_PARAM Request parameter for baseline.
static String	MEASUREMENT_UNITS_PARAM
static String	SHOW_AVERAGE_PARAM Request parameter for whether or not to show average.
static String	SHOW_BASELINE_PARAM Request parameter for whether or not to show baseline.
static String	SHOW_HIGHRANGE_PARAM Request parameter for whether or not to show high range.
static String	SHOW_LOW_PARAM Request parameter for whether or not to show the low.
static String	SHOW_LOWRANGE_PARAM Request parameter for whether or not to show low range.
static String	SHOW_PEAK_PARAM Request parameter for whether or not to show the peak.
static String	SHOW_VALUES_PARAM Request parameter for whether or not to show the actual values.
protected org.rhq.core.domain.measurement.MeasurementUnits	units

Fields inherited from class org.rhq.enterprise.gui.common.servlet.ImageServlet

IMAGE_FORMAT_JPEG, IMAGE_FORMAT_PARAM, IMAGE_FORMAT_PNG, IMAGE_HEIGHT_PARAM, IMAGE_WIDTH_PARAM

Constructor Summary

ChartServlet()

Method Summary

protected abstract Chart	createChart() Create and return the chart.
protected Object	createImage(javax.servlet.http.HttpServletRequest request) Create the image being rendered.
protected int	getDefaultImageHeight() Return the default imageHeight.
protected int	getDefaultImageWidth() Return the default imageWidth.
protected boolean	getDefaultShowAverage() Return the default showAverage.
protected boolean	getDefaultShowBaseline() Return the default showBaseline.
protected boolean	getDefaultShowHighRange() Return the default showHighRange.
protected boolean	getDefaultShowLow() Return the default showLow.
protected boolean	getDefaultShowLowRange() Return the default Range.
protected boolean	getDefaultShowPeak() Return the default showPeak.
protected boolean	getDefaultShowValues() Return the default showValues.
boolean	getShowAvg() Return the value of property showAverage.
boolean	getShowLow() Return the value of property showLow.
boolean	getShowPeak() Return the value of property showPeak.
protected void	initializeChart(Chart chart) Initialize the chart.
protected void	parseParameters(javax.servlet.http.HttpServletRequest request) This method will be called automatically by the ChartServlet.
protected abstract void	plotData(javax.servlet.http.HttpServletRequest request, Chart chart) This method will be called automatically by the ChartServlet.
protected void	renderJpegImage(javax.servlet.ServletOutputStream out, Object imgObj) Render a JPEG version of the image into the output stream.
protected void	renderPngImage(javax.servlet.ServletOutputStream out, Object imgObj) Render a PNG version of the image into the output stream.

Methods inherited from class org.rhq.enterprise.gui.common.servlet.ImageServlet

doGet, getDefaultImageFormat, getImageFormat, getImageHeight, getImageWidth, init

Methods inherited from class org.rhq.enterprise.gui.common.servlet.ParameterizedServlet

invalidParamErr, invalidParamErr, invalidParamWarn, invalidParamWarn, invalidParamWarn, invalidParamWarn, invalidParamWarn, parseBooleanParameter, parseDoubleParameter, parseEnumParameter, parseIntParameter, parseLongParameter, parseRequiredBooleanParameter, parseRequiredDoubleParameter, parseRequiredIntParameter, parseRequiredLongParameter, parseRequiredStringParameter, parseRequiredStringParameter, parseStringParameter, parseStringParameter, requiredParamErr

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

MEASUREMENT_UNITS_PARAM

public static final String MEASUREMENT_UNITS_PARAM

See Also:

Constant Field Values

IMAGE_WIDTH_DEFAULT

public static final int IMAGE_WIDTH_DEFAULT

Default image width.

See Also:

Constant Field Values

IMAGE_HEIGHT_DEFAULT

public static final int IMAGE_HEIGHT_DEFAULT

Default image height.

See Also:

Constant Field Values

SHOW_PEAK_PARAM

public static final String SHOW_PEAK_PARAM

Request parameter for whether or not to show the peak.

See Also:

Constant Field Values

SHOW_HIGHRANGE_PARAM

public static final String SHOW_HIGHRANGE_PARAM

Request parameter for whether or not to show high range.

See Also:

Constant Field Values

SHOW_VALUES_PARAM

public static final String SHOW_VALUES_PARAM

Request parameter for whether or not to show the actual values.

See Also:

Constant Field Values

SHOW_AVERAGE_PARAM

public static final String SHOW_AVERAGE_PARAM

Request parameter for whether or not to show average.

See Also:

Constant Field Values

SHOW_LOWRANGE_PARAM

public static final String SHOW_LOWRANGE_PARAM

Request parameter for whether or not to show low range.

See Also:

Constant Field Values

SHOW_LOW_PARAM

public static final String SHOW_LOW_PARAM

Request parameter for whether or not to show the low.

See Also:

Constant Field Values

SHOW_BASELINE_PARAM

public static final String SHOW_BASELINE_PARAM

Request parameter for whether or not to show baseline.

See Also:

Constant Field Values

BASELINE_PARAM

public static final String BASELINE_PARAM

Request parameter for baseline.

See Also:

Constant Field Values

HIGHRANGE_PARAM

public static final String HIGHRANGE_PARAM

Request parameter for baseline.

See Also:

Constant Field Values

LOWRANGE_PARAM

public static final String LOWRANGE_PARAM

Request parameter for baseline.

See Also:

Constant Field Values

units

protected org.rhq.core.domain.measurement.MeasurementUnits units

Constructor Detail

ChartServlet

public ChartServlet()

Method Detail

createImage

protected Object createImage(javax.servlet.http.HttpServletRequest request)
                      throws javax.servlet.ServletException

Create the image being rendered.

Specified by:

createImage in class ImageServlet

Parameters:

request - the servlet request

Throws:

javax.servlet.ServletException

renderPngImage

protected void renderPngImage(javax.servlet.ServletOutputStream out,
                              Object imgObj)
                       throws IOException

Render a PNG version of the image into the output stream.

Specified by:

renderPngImage in class ImageServlet

Parameters:

out - the output stream

Throws:

IOException

renderJpegImage

protected void renderJpegImage(javax.servlet.ServletOutputStream out,
                               Object imgObj)
                        throws IOException

Render a JPEG version of the image into the output stream.

Specified by:

renderJpegImage in class ImageServlet

Parameters:

out - the output stream

Throws:

IOException

parseParameters

protected void parseParameters(javax.servlet.http.HttpServletRequest request)

This method will be called automatically by the ChartServlet. It should handle the parsing and error-checking of any specific parameters for the chart being rendered.

Overrides:

parseParameters in class ImageServlet

Parameters:

request - the HTTP request object

createChart

protected abstract Chart createChart()

Create and return the chart. This method will be called after the parameters have been parsed.

Returns:

the newly created chart

initializeChart

protected void initializeChart(Chart chart)

Initialize the chart. This method will be called after the parameters have been parsed and the chart has been created.

Parameters:

chart - the chart

plotData

protected abstract void plotData(javax.servlet.http.HttpServletRequest request,
                                 Chart chart)
                          throws javax.servlet.ServletException

This method will be called automatically by the ChartServlet. It should handle adding data to the chart, setting up the X and Y axis labels, etc.

Parameters:

request - the HTTP request

Throws:

javax.servlet.ServletException

getShowLow

public boolean getShowLow()

Return the value of property showLow.

getShowPeak

public boolean getShowPeak()

Return the value of property showPeak.

getShowAvg

public boolean getShowAvg()

Return the value of property showAverage.

getDefaultImageWidth

protected int getDefaultImageWidth()

Return the default imageWidth.

Overrides:

getDefaultImageWidth in class ImageServlet

getDefaultImageHeight

protected int getDefaultImageHeight()

Return the default imageHeight.

Overrides:

getDefaultImageHeight in class ImageServlet

getDefaultShowPeak

protected boolean getDefaultShowPeak()

Return the default showPeak.

getDefaultShowHighRange

protected boolean getDefaultShowHighRange()

Return the default showHighRange.

getDefaultShowValues

protected boolean getDefaultShowValues()

Return the default showValues.

getDefaultShowAverage

protected boolean getDefaultShowAverage()

Return the default showAverage.

getDefaultShowLowRange

protected boolean getDefaultShowLowRange()

Return the default Range.

getDefaultShowLow

protected boolean getDefaultShowLow()

Return the default showLow.

getDefaultShowBaseline

protected boolean getDefaultShowBaseline()

Return the default showBaseline.