spring task @Scheduled注解各参数的用法

目录

• 参数详解

• 1. cron
• 2. zone
• 3. fixedDelay
• 4. fixedDelayString
• 5. fixedRate
• 6. fixedRateString
• 7. initialDelay
• 8. initialDelayString

@Scheduled(fixedDelay = 5000) //上一次执行完毕时间点之后5秒再执行

    @Scheduled(fixedDelayString = "${time.fixedDelay}")
    void testFixedDelayString() {
        System.out.println("Execute at " + System.currentTimeMillis());
    }

@Scheduled(fixedRate = 5000) //上一次开始执行时间点之后5秒再执行

@Scheduled(initialDelay=1000, fixedRate=5000) //第一次延迟1秒后执行，之后按fixedRate的规则每5秒执行一次

/**
 * An annotation that marks a method to be scheduled. Exactly one of
 * the {@link #cron()}, {@link #fixedDelay()}, or {@link #fixedRate()}
 * attributes must be specified.
 *
 * <p>The annotated method must expect no arguments. It will typically have
 * a {@code void} return type; if not, the returned value will be ignored
 * when called through the scheduler.
 *
 * <p>Processing of {@code @Scheduled} annotations is performed by
 * registering a {@link ScheduledAnnotationBeanPostProcessor}. This can be
 * done manually or, more conveniently, through the {@code <task:annotation-driven/>}
 * element or @{@link EnableScheduling} annotation.
 *
 * <p>This annotation may be used as a <em>meta-annotation</em> to create custom
 * <em>composed annotations</em> with attribute overrides.
 *
 * @author Mark Fisher
 * @author Dave Syer
 * @author Chris Beams
 * @since 3.0
 * @see EnableScheduling
 * @see ScheduledAnnotationBeanPostProcessor
 * @see Schedules
 */
@Target({ElementType.METHOD, ElementType.ANNOTATION_TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Repeatable(Schedules.class)
public @interface Scheduled {
    /**
     * A cron-like expression, extending the usual UN*X definition to include
     * triggers on the second as well as minute, hour, day of month, month
     * and day of week.  e.g. {@code "0 * * * * MON-FRI"} means once per minute on
     * weekdays (at the top of the minute - the 0th second).
     * @return an expression that can be parsed to a cron schedule
     * @see org.springframework.scheduling.support.CronSequenceGenerator
     */
    String cron() default "";
    /**
     * A time zone for which the cron expression will be resolved. By default, this
     * attribute is the empty String (i.e. the server's local time zone will be used).
     * @return a zone id accepted by {@link java.util.TimeZone#getTimeZone(String)},
     * or an empty String to indicate the server's default time zone
     * @since 4.0
     * @see org.springframework.scheduling.support.CronTrigger#CronTrigger(String, java.util.TimeZone)
     * @see java.util.TimeZone
     */
    String zone() default "";
    /**
     * Execute the annotated method with a fixed period in milliseconds between the
     * end of the last invocation and the start of the next.
     * @return the delay in milliseconds
     */
    long fixedDelay() default -1;
    /**
     * Execute the annotated method with a fixed period in milliseconds between the
     * end of the last invocation and the start of the next.
     * @return the delay in milliseconds as a String value, e.g. a placeholder
     * @since 3.2.2
     */
    String fixedDelayString() default "";
    /**
     * Execute the annotated method with a fixed period in milliseconds between
     * invocations.
     * @return the period in milliseconds
     */
    long fixedRate() default -1;
    /**
     * Execute the annotated method with a fixed period in milliseconds between
     * invocations.
     * @return the period in milliseconds as a String value, e.g. a placeholder
     * @since 3.2.2
     */
    String fixedRateString() default "";
    /**
     * Number of milliseconds to delay before the first execution of a
     * {@link #fixedRate()} or {@link #fixedDelay()} task.
     * @return the initial delay in milliseconds
     * @since 3.2
     */
    long initialDelay() default -1;
    String initialDelayString() default "";
}

<context:annotation-config />  
<!--spring扫描注解的配置   -->  
<context:component-scan base-package="com.baodian.bdweb.timer" /> 
<!--  开启这个配置，spring才能识别@Scheduled注解     -->
<task:annotation-driven scheduler="qbScheduler" mode="proxy"/>  
<task:scheduler id="qbScheduler" pool-size="10"/>

@Component("Taskaa")
public class Taskaa{
 @Scheduled(cron = "01 50 15 * * ?")
 public void show(){
  SimpleDateFormat s = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  System.out.println("Taskaa:"+s.format(new Date()));  
 }
}<pre name="code" class="java">@Component("Taskbb")
public class Taskbb{
 @Scheduled(cron = "01 49 15 * * ?")
 public void show(){
  SimpleDateFormat s = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  System.out.println("Taskbb:"+s.format(new Date()));  
 }
}

<context:annotation-config />  
<!--spring扫描注解的配置   -->  
<context:component-scan base-package="com.baodian.bdweb.timer" /> 
<bean id="Taskaa" class="com.baodian.bdweb.timer.Taskaa" />  
<bean id="Taskbb" class="com.baodian.bdweb.timer.Taskbb" />  
<task:scheduled-tasks>  
     <task:scheduled ref="Taskaa" method="show" cron="01 38 15 * * ?" />  
     <task:scheduled ref="Taskbb" method="show" cron="01 39 15 * * ?" /> 
</task:scheduled-tasks>

@Component("Taskaa")
public class Taskaa{
 @Scheduled
 public void show(){
  SimpleDateFormat s = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  System.out.println("Taskaa:"+s.format(new Date()));  
 }
}

@Component("Taskbb")
public class Taskbb{
 @Scheduled
 public void show(){
  SimpleDateFormat s = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  System.out.println("Taskbb:"+s.format(new Date()));  
 }
}