Java tutorial
/** * 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.zookeeper.graph.servlets; import java.io.IOException; import java.io.BufferedOutputStream; import java.io.FileOutputStream; import java.io.DataOutputStream; import java.io.PrintStream; import java.util.HashSet; import java.util.LinkedHashMap; import org.apache.zookeeper.graph.*; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.json.simple.JSONArray; import org.json.simple.JSONObject; import org.json.simple.JSONValue; public class Throughput extends JsonServlet { private static final int MS_PER_SEC = 1000; private static final int MS_PER_MIN = MS_PER_SEC * 60; private static final int MS_PER_HOUR = MS_PER_MIN * 60; private LogSource source = null; public Throughput(LogSource src) throws Exception { this.source = src; } public String handleRequest(JsonRequest request) throws Exception { long starttime = 0; long endtime = 0; long period = 0; long scale = 0; starttime = request.getNumber("start", 0); endtime = request.getNumber("end", 0); period = request.getNumber("period", 0); if (starttime == 0) { starttime = source.getStartTime(); } if (endtime == 0) { if (period > 0) { endtime = starttime + period; } else { endtime = source.getEndTime(); } } String scalestr = request.getString("scale", "minutes"); if (scalestr.equals("seconds")) { scale = MS_PER_SEC; } else if (scalestr.equals("hours")) { scale = MS_PER_HOUR; } else { scale = MS_PER_MIN; } LogIterator iter = source.iterator(starttime, endtime); long current = 0; long currentms = 0; HashSet<Long> zxids_ms = new HashSet<Long>(); long zxidcount = 0; JSONArray events = new JSONArray(); while (iter.hasNext()) { LogEntry e = iter.next(); if (e.getType() != LogEntry.Type.TXN) { continue; } TransactionEntry cxn = (TransactionEntry) e; long ms = cxn.getTimestamp(); long inscale = ms / scale; if (currentms != ms && currentms != 0) { zxidcount += zxids_ms.size(); zxids_ms.clear(); } if (inscale != current && current != 0) { JSONObject o = new JSONObject(); o.put("time", current * scale); o.put("count", zxidcount); events.add(o); zxidcount = 0; } current = inscale; currentms = ms; zxids_ms.add(cxn.getZxid()); } JSONObject o = new JSONObject(); o.put("time", current * scale); o.put("count", zxidcount); events.add(o); iter.close(); return JSONValue.toJSONString(events); } };