新增：ScheduledExecutorService的使用

Author: JeffLi1993

src/org/javacore/scheduler/SchedulerExecutorTest.java

@@ -0,0 +1,46 @@
+package org.javacore.scheduler; /*
+ * Copyright [2015] [Jeff Lee]
+ *
+ * Licensed 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.
+ */
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * ScheduledExecutorService的使用
+ * @author BYSocket
+ * @since 2016-01-10 14:20:00
+ */
+public class SchedulerExecutorTest implements
+        Runnable {
+    private final String jobName;
+
+    public SchedulerExecutorTest(String jobName) {
+        this.jobName = jobName;
+    }
+
+    @Override
+    public void run() {
+        System.out.println("running => " + jobName);
+    }
+
+    public static void main(String[] args) {
+        ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
+        // 一秒
+        executor.scheduleAtFixedRate(new SchedulerExecutorTest("job1"), 1, 1, TimeUnit.SECONDS);
+        // 两秒
+        executor.scheduleWithFixedDelay(new SchedulerExecutorTest("job2"),1,2,TimeUnit.SECONDS);
+    }
+}

src/org/javacore/scheduler/SchedulerExecutorTest2.java

@@ -0,0 +1,116 @@
+package org.javacore.scheduler; /*
+ * Copyright [2015] [Jeff Lee]
+ *
+ * Licensed 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.
+ */
+
+import java.util.Calendar;
+import java.util.Date;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * ScheduledExecutorService的使用
+ * @author BYSocket
+ * @since 2016-01-10 22:02:00
+ */
+public class SchedulerExecutorTest2 implements Runnable{
+
+    private final String jobName;
+
+    public SchedulerExecutorTest2(String jobName) {
+        this.jobName = jobName;
+    }
+
+    @Override
+    public void run() {
+        System.out.println("Date = " + new Date() + ", running => " + jobName);
+    }
+
+    /**
+     * 计算从当前时间currentDate开始，满足条件dayOfWeek, hourOfDay,
+     * minuteOfHour, secondOfMinite的最近时间
+     * @return
+     */
+    public Calendar getEarliestDate(Calendar currentDate, int dayOfWeek,
+                                    int hourOfDay, int minuteOfHour, int secondOfMinite) {
+        //计算当前时间的WEEK_OF_YEAR,DAY_OF_WEEK, HOUR_OF_DAY, MINUTE,SECOND等各个字段值
+        int currentWeekOfYear = currentDate.get(Calendar.WEEK_OF_YEAR);
+        int currentDayOfWeek = currentDate.get(Calendar.DAY_OF_WEEK);
+        int currentHour = currentDate.get(Calendar.HOUR_OF_DAY);
+        int currentMinute = currentDate.get(Calendar.MINUTE);
+        int currentSecond = currentDate.get(Calendar.SECOND);
+
+        //如果输入条件中的dayOfWeek小于当前日期的dayOfWeek,则WEEK_OF_YEAR需要推迟一周
+        boolean weekLater = false;
+        if (dayOfWeek < currentDayOfWeek) {
+            weekLater = true;
+        } else if (dayOfWeek == currentDayOfWeek) {
+            //当输入条件与当前日期的dayOfWeek相等时，如果输入条件中的
+            //hourOfDay小于当前日期的
+            //currentHour，则WEEK_OF_YEAR需要推迟一周
+            if (hourOfDay < currentHour) {
+                weekLater = true;
+            } else if (hourOfDay == currentHour) {
+                //当输入条件与当前日期的dayOfWeek, hourOfDay相等时，
+                //如果输入条件中的minuteOfHour小于当前日期的
+                //currentMinute，则WEEK_OF_YEAR需要推迟一周
+                if (minuteOfHour < currentMinute) {
+                    weekLater = true;
+                } else if (minuteOfHour == currentSecond) {
+                    //当输入条件与当前日期的dayOfWeek, hourOfDay，
+                    //minuteOfHour相等时，如果输入条件中的
+                    //secondOfMinite小于当前日期的currentSecond，
+                    //则WEEK_OF_YEAR需要推迟一周
+                    if (secondOfMinite < currentSecond) {
+                        weekLater = true;
+                    }
+                }
+            }
+        }
+        if (weekLater) {
+            //设置当前日期中的WEEK_OF_YEAR为当前周推迟一周
+            currentDate.set(Calendar.WEEK_OF_YEAR, currentWeekOfYear + 1);
+        }
+        // 设置当前日期中的DAY_OF_WEEK,HOUR_OF_DAY,MINUTE,SECOND为输入条件中的值。
+        currentDate.set(Calendar.DAY_OF_WEEK, dayOfWeek);
+        currentDate.set(Calendar.HOUR_OF_DAY, hourOfDay);
+        currentDate.set(Calendar.MINUTE, minuteOfHour);
+        currentDate.set(Calendar.SECOND, secondOfMinite);
+        return currentDate;
+
+    }
+
+    public static void main(String[] args) {
+        SchedulerExecutorTest2 executor = new SchedulerExecutorTest2("job1");
+        // 获取当前时间
+        Calendar currentDate = Calendar.getInstance();
+        long currentDateLong = currentDate.getTime().getTime();
+        System.out.println("Current Date = " + currentDate.getTime().toString());
+        // 计算满足条件的最近一次执行时间
+        Calendar earliestDate = executor.getEarliestDate(currentDate,3,16,38,10);
+        long earliestDateLong = earliestDate.getTime().getTime();
+        System.out.println("Earliest Date = " + earliestDate.getTime().toString());
+        // 计算从当前时间到最近一次执行时间的时间间隔
+        long delay = earliestDateLong - currentDateLong;
+        // 计算执行周期为一星期
+//        long period = 7 * 24 * 60 * 60 * 1000;
+        long period = 1000;
+        ScheduledExecutorService service = Executors.newScheduledThreadPool(10);
+        // 从现在开始delay毫秒之后，每隔一星期执行一次job1
+        service.scheduleAtFixedRate(executor, delay, period,
+                TimeUnit.MILLISECONDS);
+    }
+
+}