Java tutorial
/* * Copyright (c) 2012, Codice Foundation. All rights reserved. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 3 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, * MA 02110-1301 USA */ package org.codice.ddf.status; import java.io.IOException; import java.io.PrintWriter; import java.util.Calendar; import java.util.LinkedHashMap; import java.util.Map; import java.util.logging.Level; import java.util.logging.Logger; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.hyperic.sigar.CpuPerc; import org.hyperic.sigar.Sigar; import org.hyperic.sigar.SigarException; import org.json.simple.JSONValue; public class CpuService extends HttpServlet { private static final long serialVersionUID = 1L; private static Logger logger = Logger.getLogger("org.codice.ddf.CpuService"); protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { PrintWriter writer = response.getWriter(); writer.append(toJSON()); } static Map<String, Object> getCpuStatus() { Map<String, Object> obj = new LinkedHashMap<String, Object>(); Sigar sigar = null; try { sigar = new Sigar(); // call it to make sure the library was loaded sigar.getPid(); org.hyperic.sigar.CpuInfo[] cpuinfo = null; try { cpuinfo = sigar.getCpuInfoList(); } catch (SigarException se) { se.printStackTrace(); } org.hyperic.sigar.CpuPerc[] cpuperc = null; try { cpuperc = sigar.getCpuPercList(); } catch (SigarException se) { se.printStackTrace(); } Map<String, Object> data = new LinkedHashMap<String, Object>(); for (int i = 0; i < cpuinfo.length; i++) { @SuppressWarnings("unchecked") Map<String, Object> cpu = cpuinfo[i].toMap(); cpu.put("User", cpuperc[i].getUser()); cpu.put("Sys", cpuperc[i].getSys()); data.put("CPU" + i, cpu); } obj.put("data", data); obj.put("type", "cpu"); obj.put("time", new java.sql.Timestamp(Calendar.getInstance().getTime().getTime()).toString()); sigar.close(); } catch (Throwable t) { t.fillInStackTrace(); logger.log(Level.SEVERE, "Failed to load sigar", t); if (sigar != null) { try { sigar.close(); } catch (Throwable t1) { // ignore } finally { sigar = null; } } } return obj; } static String toJSON() { return JSONValue.toJSONString(getCpuStatus()); } }