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1
17 package org.apache.servicemix.components.util;
18
19 import java.util.Date  ;
20
21 import javax.jbi.JBIException;
22 import javax.resource.spi.work.Work ;
23 import javax.resource.spi.work.WorkManager ;
24
25 import org.apache.commons.logging.Log;
26 import org.apache.commons.logging.LogFactory;
27 import org.apache.servicemix.components.varscheduler.ScheduleIterator;
28 import org.apache.servicemix.components.varscheduler.Scheduler;
29 import org.apache.servicemix.components.varscheduler.SchedulerTask;
30 import org.apache.servicemix.jbi.framework.ComponentContextImpl;
31
32
38 public abstract class PollingComponentSupport extends ComponentSupport implements Work {
39 private static final Log log = LogFactory.getLog(PollingComponentSupport.class);
40 private WorkManager workManager;
41 private Scheduler scheduler;
42 private Date firstTime;
43 private long period = 5000;
44 private long delay;
45 private SchedulerTask schedulerTask;
46 private ScheduleIterator scheduleIterator;
47 private boolean started;
48 private boolean scheduleExecutedFlag;
49
50
55 public abstract void poll() throws Exception ;
56
57 public void release() {
58 }
59
60 public void run() {
61 try {
62 poll();
63 }
64 catch (Exception e) {
65 log.error("Caught exception while polling: " + e, e);
66 }
67 }
68
69 public WorkManager getWorkManager() {
72 return workManager;
73 }
74
75 public void setWorkManager(WorkManager workManager) {
76 this.workManager = workManager;
77 }
78
79 public long getDelay() {
80 return delay;
81 }
82
83 public void setDelay(long delay) {
84 this.delay = delay;
85 }
86
87 public Date getFirstTime() {
88 return firstTime;
89 }
90
91 public void setFirstTime(Date firstTime) {
92 this.firstTime = firstTime;
93 }
94
95 public long getPeriod() {
96 return period;
97 }
98
99 public void setPeriod(long period) {
100 this.period = period;
101 }
102
103 public Scheduler getScheduler() {
104 return scheduler;
105 }
106
107 public void setScheduler(Scheduler scheduler) {
108 this.scheduler = scheduler;
109 }
110
111 public synchronized void start() throws JBIException {
112 if (!started) {
113 started = true;
114 if (schedulerTask != null) {
115 schedulerTask.cancel();
116 }
117 schedulerTask = new PollSchedulerTask();
118 this.scheduler.schedule(schedulerTask,scheduleIterator);
119 }
120 super.start();
121 }
122
123 public synchronized void stop() throws JBIException {
124 if (schedulerTask != null) {
125 schedulerTask.cancel();
126 schedulerTask = null;
127 }
128 scheduleExecutedFlag = false;
129 started = false;
130 super.stop();
131 }
132
133 public synchronized void shutDown() throws JBIException {
134 stop();
135 scheduler.cancel();
136 scheduler = null;
137 scheduleIterator = null;
138 workManager = null;
139 super.shutDown();
140 }
141
142 protected void init() throws JBIException {
145 if (scheduler == null) {
146 scheduler = new Scheduler(true);
147 }
148 if (scheduleIterator == null) {
149 scheduleIterator = new PollScheduleIterator();
150 }
151 if (workManager == null) {
152 ComponentContextImpl context = (ComponentContextImpl) getContext();
153 workManager = context.getWorkManager();
154 }
155 super.init();
156
157 }
158
159 private class PollSchedulerTask extends SchedulerTask {
160 public void run() {
161 try {
162 getWorkManager().doWork(PollingComponentSupport.this);
165 }
166 catch (Throwable e) {
167 log.error("Failed to schedule work: " + e, e);
168 }
169 }
170 }
171
172 private class PollScheduleIterator implements ScheduleIterator {
173 public Date nextExecution() {
174 long nextTime = System.currentTimeMillis();
175 if (scheduleExecutedFlag) {
176 nextTime += period;
177 } else {
178 if (firstTime != null) {
179 nextTime = firstTime.getTime();
180 }
181 nextTime += delay;
182 scheduleExecutedFlag = true;
183 }
184 return (started) ? new Date (nextTime) : null;
185 }
186 }
187 } |
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