/*
* 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.tools.ant.taskdefs;
import java.util.HashMap;
import java.util.Map;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.taskdefs.condition.Condition;
import org.apache.tools.ant.taskdefs.condition.ConditionBase;
import org.apache.tools.ant.types.EnumeratedAttribute;
/**
* Wait for an external event to occur.
*
* Wait for an external process to start or to complete some
* task. This is useful with the <code>parallel</code> task to
* synchronize the execution of tests with server startup.
*
* The following attributes can be specified on a waitfor task:
* <ul>
* <li>maxwait - maximum length of time to wait before giving up</li>
* <li>maxwaitunit - The unit to be used to interpret maxwait attribute</li>
* <li>checkevery - amount of time to sleep between each check</li>
* <li>checkeveryunit - The unit to be used to interpret checkevery attribute</li>
* <li>timeoutproperty - name of a property to set if maxwait has been exceeded.</li>
* </ul>
*
* The maxwaitunit and checkeveryunit are allowed to have the following values:
* millisecond, second, minute, hour, day and week. The default is millisecond.
*
* For programmatic use/subclassing, there are two methods that may be overrridden,
* <code>processSuccess</code> and <code>processTimeout</code>
* @since Ant 1.5
*
* @ant.task category="control"
*/
public class WaitFor extends ConditionBase {
/** default max wait time */
private long maxWaitMillis = 1000L * 60L * 3L;
private long maxWaitMultiplier = 1L;
private long checkEveryMillis = 500L;
private long checkEveryMultiplier = 1L;
private String timeoutProperty;
/**
* Constructor, names this task "waitfor".
*/
public WaitFor() {
super("waitfor");
}
/**
* Set the maximum length of time to wait.
* @param time a <code>long</code> value
*/
public void setMaxWait(long time) {
maxWaitMillis = time;
}
/**
* Set the max wait time unit
* @param unit an enumerated <code>Unit</code> value
*/
public void setMaxWaitUnit(Unit unit) {
maxWaitMultiplier = unit.getMultiplier();
}
/**
* Set the time between each check
* @param time a <code>long</code> value
*/
public void setCheckEvery(long time) {
checkEveryMillis = time;
}
/**
* Set the check every time unit
* @param unit an enumerated <code>Unit</code> value
*/
public void setCheckEveryUnit(Unit unit) {
checkEveryMultiplier = unit.getMultiplier();
}
/**
* Name the property to set after a timeout.
* @param p the property name
*/
public void setTimeoutProperty(String p) {
timeoutProperty = p;
}
/**
* Check repeatedly for the specified conditions until they become
* true or the timeout expires.
* @throws BuildException on error
*/
public void execute() throws BuildException {
if (countConditions() > 1) {
throw new BuildException("You must not nest more than one "
+ "condition into "
+ getTaskName());
}
if (countConditions() < 1) {
throw new BuildException("You must nest a condition into "
+ getTaskName());
}
Condition c = (Condition) getConditions().nextElement();
long savedMaxWaitMillis = maxWaitMillis;
long savedCheckEveryMillis = checkEveryMillis;
try {
maxWaitMillis *= maxWaitMultiplier;
checkEveryMillis *= checkEveryMultiplier;
long start = System.currentTimeMillis();
long end = start + maxWaitMillis;
while (System.currentTimeMillis() < end) {
if (c.eval()) {
processSuccess();
return;
}
try {
Thread.sleep(checkEveryMillis);
} catch (InterruptedException e) {
// ignore
}
}
processTimeout();
} finally {
maxWaitMillis = savedMaxWaitMillis;
checkEveryMillis = savedCheckEveryMillis;
}
}
/**
* Actions to be taken on a successful waitfor.
* This is an override point. The base implementation does nothing.
* @since Ant1.7
*/
protected void processSuccess() {
log(getTaskName() + ": condition was met", Project.MSG_VERBOSE);
}
/**
* Actions to be taken on an unsuccessful wait.
* This is an override point. It is where the timeout processing takes place.
* The base implementation sets the timeoutproperty if there was a timeout
* and the property was defined.
* @since Ant1.7
*/
protected void processTimeout() {
log(getTaskName() + ": timeout", Project.MSG_VERBOSE);
if (timeoutProperty != null) {
getProject().setNewProperty(timeoutProperty, "true");
}
}
/**
* The enumeration of units:
* millisecond, second, minute, hour, day, week
* @todo we use timestamps in many places, why not factor this out
*/
public static class Unit extends EnumeratedAttribute {
/** millisecond string */
public static final String MILLISECOND = "millisecond";
/** second string */
public static final String SECOND = "second";
/** minute string */
public static final String MINUTE = "minute";
/** hour string */
public static final String HOUR = "hour";
/** day string */
public static final String DAY = "day";
/** week string */
public static final String WEEK = "week";
private static final String[] UNITS = {
MILLISECOND, SECOND, MINUTE, HOUR, DAY, WEEK
};
private Map timeTable = new HashMap();
/** Constructor the Unit enumerated type. */
public Unit() {
timeTable.put(MILLISECOND, new Long(1L));
timeTable.put(SECOND, new Long(1000L));
timeTable.put(MINUTE, new Long(1000L * 60L));
timeTable.put(HOUR, new Long(1000L * 60L * 60L));
timeTable.put(DAY, new Long(1000L * 60L * 60L * 24L));
timeTable.put(WEEK, new Long(1000L * 60L * 60L * 24L * 7L));
}
/**
* Convert the value to a multipler (millisecond to unit).
* @return a multipler (a long value)
*/
public long getMultiplier() {
String key = getValue().toLowerCase();
Long l = (Long) timeTable.get(key);
return l.longValue();
}
/**
* @see EnumeratedAttribute#getValues()
*/
/** {@inheritDoc} */
public String[] getValues() {
return UNITS;
}
}
}
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