import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.Date;
public class SystemMonitor extends HttpServlet
{
private String adjust(long val)
{
int mils = 0;
int thou = 0;
if(val > 1000000) //million
{
mils = (int) (val / 1000000);
val = val % 1000000;
}
if(val > 1000) //thousands
{
thou = (int) (val / 1000);
}
if(mils > 0)
{
String result = "" + thou;
while(result.length() < 3)
{
result = "0" + result;
}
return(mils + "." + result + "M");
}
else
{
return(thou + "k");
}
}
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("");
out.println("");
out.println("");
out.println("Hello World!");
out.println("");
out.println("");
Runtime runtime = Runtime.getRuntime();
int procs = runtime.availableProcessors();
String max = adjust(runtime.maxMemory());
String total = adjust(runtime.totalMemory());
String used = adjust(runtime.totalMemory() - runtime.freeMemory());
String free = adjust(runtime.freeMemory());
String hostName = request.getServerName();
String date = (new Date()).toString();
out.println("Current Performance Statistics
");
out.println("For " + hostName + "
");
out.println("As of " + date + "
");
out.println("
Available processors: " + procs);
out.println("
Maximum memory available (total expandable to): " + max);
out.println("
Total memory allocated to JVM (used and unused): " + total);
out.println("
Used memory (memory in use): " + used);
out.println("
Free memory (memory unused): " + free);
out.println("
Active Thread Count: " + Thread.activeCount());
out.println("");
out.println("");
}
public String getRequestURL(HttpServletRequest request)
{
return(request.getScheme() + "://" +
request.getServerName() + ":" +
request.getServerPort() +
request.getRequestURI());
}
}