/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied.
*
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.excalibur.instrument.manager.http;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import java.util.Map;
import org.apache.excalibur.instrument.manager.http.server.HTTPRedirect;
import org.apache.excalibur.instrument.manager.DefaultInstrumentManager;
import org.apache.excalibur.instrument.manager.InstrumentSampleDescriptor;
import org.apache.excalibur.instrument.manager.InstrumentSampleSnapshot;
import org.apache.excalibur.instrument.manager.NoSuchInstrumentSampleException;
/**
*
* @author <a href="mailto:dev@avalon.apache.org">Avalon Development Team</a>
* @version CVS $Revision: 1.9 $ $Date: 2004/03/09 14:33:06 $
* @since 4.1
*/
public class HTMLSampleHandler
extends AbstractHTMLHandler
{
/*---------------------------------------------------------------
* Constructors
*-------------------------------------------------------------*/
/**
* Creates a new HTMLSampleHandler.
*
* @param manager Reference to the DefaultInstrumentManager.
* @param connector The InstrumentManagerHTTPConnector.
*/
public HTMLSampleHandler( DefaultInstrumentManager manager,
InstrumentManagerHTTPConnector connector )
{
super( "/sample.html", manager, connector );
}
/*---------------------------------------------------------------
* AbstractHTTPURLHandler Methods
*-------------------------------------------------------------*/
/**
* Handles the specified request.
*
* @param The full path being handled.
* @param parameters A Map of the parameters in the request.
* @param os The PrintWriter to write the result to.
*/
public void doGet( String path, Map parameters, PrintWriter out )
throws IOException
{
String name = getParameter( parameters, "name" );
InstrumentSampleDescriptor desc;
try
{
desc = getInstrumentManager().locateInstrumentSampleDescriptor( name );
}
catch ( NoSuchInstrumentSampleException e )
{
// Sample no longer exists, go back to the parent instrument.
int pos = name.lastIndexOf( '.' );
if ( pos >= 0 )
{
throw new HTTPRedirect(
"instrument.html?name=" + urlEncode( name.substring( 0, pos ) ) );
}
else
{
throw new HTTPRedirect( "instrument-manager.html" );
}
}
String chart = getParameter( parameters, "chart", null );
InstrumentSampleSnapshot snapshot = desc.getSnapshot();
String type;
switch ( desc.getType() )
{
case DefaultInstrumentManager.INSTRUMENT_SAMPLE_TYPE_COUNTER:
type = "Counter";
break;
case DefaultInstrumentManager.INSTRUMENT_SAMPLE_TYPE_MAXIMUM:
type = "Max Value";
break;
case DefaultInstrumentManager.INSTRUMENT_SAMPLE_TYPE_MINIMUM:
type = "Min Value";
break;
case DefaultInstrumentManager.INSTRUMENT_SAMPLE_TYPE_MEAN:
type = "Mean Value";
break;
default:
type = "Unknown";
break;
}
out.println( "<html>" );
out.println( "<head><title>" + desc.getDescription() + "</title></head>" );
out.println( "<body>" );
breadCrumbs( out, desc, false );
out.println( "<h2>Instrument Sample</h2>" );
startTable( out );
tableRow( out, 0, "Name", desc.getName() );
tableRow( out, 0, "Description", desc.getDescription() );
tableRow( out, 0, "Type", type );
tableRow( out, 0, "Interval", desc.getInterval() + "ms." );
tableRow( out, 0, "Size", Integer.toString( desc.getSize() ) );
if ( desc.getLeaseExpirationTime() > 0 )
{
String renewUrl = "sample-lease.html?name=" + urlEncode( desc.getName() )
+ ( chart == null ? "" : "&chart=true" ) + "&lease=";
String value = new Date( desc.getLeaseExpirationTime() ).toString();
if ( !getConnector().isReadOnly() )
{
value = value + " (Renew <a href='" + renewUrl + "600000'>10min</a>, "
+ "<a href='" + renewUrl + "3600000'>1hr</a>, "
+ "<a href='" + renewUrl + "86400000'>1day</a>)";
}
// Make the text red if it is about to expire.
if ( desc.getLeaseExpirationTime() - System.currentTimeMillis() < 300000 )
{
value = "<font color='ff0000'>" + value + "</font>";
}
tableRow( out, 0, "Expiration", value );
}
else
{
tableRow( out, 0, "Expiration", "Permanent" );
}
endTable( out );
if ( chart == null )
{
out.println( "<h2>Data Samples (<a href='sample.html?name="
+ urlEncode( desc.getName() ) + "&chart=true'>Chart</a>)</h2>" );
startTable( out );
startTableHeaderRow( out );
tableHeaderCell( out, "Period" );
tableHeaderCell( out, "Value" );
endTableHeaderRow( out );
long time = snapshot.getTime();
int[] samples = snapshot.getSamples();
for ( int i = 0; i < samples.length; i++ )
{
startTableRow( out, i );
tableCell( out, new Date( time ).toString() );
tableCellRight( out, Integer.toString( samples[samples.length - i - 1] ) );
endTableRow( out );
time -= snapshot.getInterval();
}
endTable( out );
}
else
{
out.println( "<h2>Data Samples (<a href='sample.html?name="
+ urlEncode( desc.getName() ) + "'>Plain</a>)</h2>" );
// Originally, the JavaScript timer in the page made use of the setInterval
// function to build a simple timer. This worked fine under normal
// operation. But if a browser was suspended for 1 hour with a timer
// running at 1 second intervals, the timer would try to catch up when
// the machine was resumed. This would result in the timer firing 3600
// times over the course of a few seconds. The sudden burst of requests
// was swamping the server.
// The current scripts below now always reset the timer each time it is
// fired. If the timer ever falls behind it will recover smoothly
// without trying to catch up. While not quite as accurate it is
// sufficient for our purposes.
out.println( "<SCRIPT LANGUAGE=\"JavaScript\">" );
out.println( "var timerId = 0;" );
out.println( "var timerInterval = 5000;" );
out.println( "function refreshChart() {" );
//out.println( " alert(\"in refreshChart()\");" );
out.println( " document.chart.src=\"sample-chart.jpg?name=" + urlEncode( desc.getName() ) + "&time=\" + new Date().getTime();" );
out.println( "}" );
out.println( "function timerFired() {" );
//out.println( " alert(\"in timerFired()\");" );
out.println( " if (timerId) {" );
out.println( " clearTimeout(timerId);" );
out.println( " }" );
out.println( " timerId = setTimeout(\"timerFired()\", timerInterval)" );
out.println( " refreshChart();" );
out.println( "}" );
out.println( "function setRefresh(refresh) {" );
//out.println( " alert(\"in setRefresh(\" + refresh + \")\");" );
out.println( " timerInterval = refresh;" );
out.println( " timerFired();" );
out.println( "}" );
out.println( "function chartError() {" );
//out.println( " alert(\"in chartError()\");" );
out.println( " clearTimeout(timerId);" );
out.println( " document.location=\"instrument.html?name=" + urlEncode( desc.getInstrumentDescriptor().getName() ) + "\";" );
out.println( "}" );
out.println( "</SCRIPT>" );
out.println( "<form>" );
startTable( out );
// Add a time to the chart as is done in the Javascript. Some browsers ignore the
// do not cache headers in the image and display a cached version of the image
// anyway.
tableCell( out, "<img name='chart' src='sample-chart.jpg?name=" + urlEncode( desc.getName() )
+ "&time=" + System.currentTimeMillis() + "' onError='javascript:chartError()'>" );
endTable( out );
out.println( "Refresh rate:" );
out.println( "<input type='button' value='No Refresh' onClick='javascript:clearTimeout(timerId)'>" );
out.println( "<input type='button' value='1 Second' onClick='javascript:setRefresh(1000)'>" );
out.println( "<input type='button' value='5 Seconds' onClick='javascript:setRefresh(5000)'>" );
out.println( "<input type='button' value='10 Seconds' onClick='javascript:setRefresh(10000)'>" );
out.println( "<input type='button' value='1 Minute' onClick='javascript:setRefresh(60000)'>" );
out.println( "<input type='button' value='Refresh Now' onClick='javascript:refreshChart()'>" );
out.println( "</form>" );
}
footer( out );
out.println( "</body>" );
out.println( "</html>" );
}
/*---------------------------------------------------------------
* Methods
*-------------------------------------------------------------*/
}