scheduled method invoked twice in spring 3.0.2 - spring

Question

I am using spring 3.0.2
My scheduled method is invoked twice..
am i making some mistake..?
please help me to figure it out..
#Component("happySundayGreetTask")
public class HappySundayGreetTask {
#Autowired
private JavaMailSender mailSender;
public void setMailSender(JavaMailSender mailSender) {
this.mailSender = mailSender;
}
#Value("${mail.sender}")
private String fromAddress;
public void setFromAddress(String fromAddress) {
this.fromAddress = fromAddress;
}
#Autowired
private VelocityEngine velocityEngine;
public void setVelocityEngine(VelocityEngine velocityEngine) {
this.velocityEngine = velocityEngine;
}
#Autowired
private SpitterDAO spitterDAO;
public void setSpitterDAO(SpitterDAO spitterDAO) {
this.spitterDAO = spitterDAO;
}
#Scheduled(cron="0 58 18 ? * SUN")
public void greetSundayToSpitters(){
try {
System.out.println("task started..");
MimeMessage message = mailSender.createMimeMessage();
MimeMessageHelper mimeHelper = new MimeMessageHelper(message, true);
List<String> spittersEmail = spitterDAO.getSpittersEmail(true);
String toAddress[] = spittersEmail.toArray(new String[spittersEmail.size()]);
String templateLoc = "com/spitter/task/sundayGreetEmailTemplate.vm";
String emailText = VelocityEngineUtils.mergeTemplateIntoString(velocityEngine, templateLoc, null);
mimeHelper.setFrom(fromAddress);
mimeHelper.setTo(toAddress);
mimeHelper.setSubject("Sunday Greeting from Spitter");
mimeHelper.setText(emailText, true);
mailSender.send(message);
}
catch (MessagingException ex) {
Logger.getLogger(HappySundayGreetTask.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
// spitter-servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:security="http://www.springframework.org/schema/security"
xmlns:jms="http://www.springframework.org/schema/jms"
xmlns:task="http://www.springframework.org/schema/task"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.0.xsd
http://www.springframework.org/schema/jms http://www.springframework.org/schema/jms/spring-jms-3.0.xsd
http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd
">
<!-- Defining a PropertyPlaceholderConfigurer -->
<context:property-placeholder
location="classpath:/com/spitter/dao/db.properties,
classpath:/com/spitter/service/alerts/mailserver.properties"/>
<!-- Declaring security aspects to those beans annotated with #PreAutorize -->
<security:global-method-security pre-post-annotations="enabled" />
<!-- Support for annotation driven validation, message conversion -->
<mvc:annotation-driven/>
<!-- Automatically registering controllers & service objects as beans -->
<context:component-scan base-package="com.spitter"/>
<!-- Autowiring enabled using annotations -->
<context:annotation-config/>
<!-- Using annotation driven transaction facility -->
<tx:annotation-driven transaction-manager="transactionManager"/>
<!-- Configuring a mail sender -->
<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
<!-- Configuring mail server properties -->
<property name="host" value="${mailserver.host}"/>
<property name="port" value="${mailserver.port}"/>
<property name="username" value="${mailserver.username}"/>
<property name="password" value="${mailserver.password}"/>
<!-- Other mail properties -->
<property name="javaMailProperties">
<props>
<prop key="mail.transport.protocol">${mail.transport.protocol}</prop>
<prop key="mail.smtp.auth">${mail.smtp.auth}</prop>
<prop key="mail.smtp.starttls.enable">${mail.smtp.starttls.enable}</prop>
<prop key="mail.debug">${mail.debug}</prop>
</props>
</property>
</bean>
<!-- Velocity email template used for sending email alerts -->
<bean id="velocityEngine" class="org.springframework.ui.velocity.VelocityEngineFactoryBean">
<property name="velocityProperties">
<props>
<prop key="resource.loader">class</prop>
<prop key="class.resource.loader.class">org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader</prop>
</props>
</property>
</bean>
<!-- support for scheduled and asynchronous backgorund jobs -->
<task:annotation-driven/>
</beans>
//spitter-security.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:security="http://www.springframework.org/schema/security"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.0.xsd
">
<import resource="spitter-servlet.xml"/>
<security:http auto-config="true" use-expressions="true">
<security:remember-me key="spitterKey" token-validity-seconds="86400"/>
<security:form-login login-page="/login" authentication-failure-url="/login?login_error=t"
login-processing-url="/static/j_spring_security_check"
default-target-url="/home"/>
<security:logout logout-url="/logout" logout-success-url="/login?logout=success"/>
<security:intercept-url pattern="/login" access="isAnonymous()"/>
<security:intercept-url pattern="/spitters" access="isAnonymous()"/>
<security:intercept-url pattern="/logout" access="isAuhenticated()"/>
<security:intercept-url pattern="/admin/**" access="hasRole('ROLE_ADMIN')"/>
</security:http>
<security:authentication-manager>
<security:authentication-provider user-service-ref="spitterServiceImpl">
<security:password-encoder hash="md5"/>
</security:authentication-provider>
</security:authentication-manager>
</beans>
//web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>
/WEB-INF/spitter-security.xml
</param-value>
</context-param>
<filter>
<description>Filter used to identify requests for PUT & DELETE requests as the case with RESTFul verbs</description>
<filter-name>httpMethodFilter</filter-name>
<filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>httpMethodFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter>
<description>Spring security servlet filter delegates to spring managed security filter(Spring security filter)</description>
<filter-name>springSecurityFilterChain</filter-name>
<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
<filter-name>springSecurityFilterChain</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<listener>
<listener-class>com.sun.xml.ws.transport.http.servlet.WSServletContextListener</listener-class>
</listener>
<servlet>
<servlet-name>spitter</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>2</load-on-startup>
</servlet>
<servlet>
<description>Handles static content</description>
<servlet-name>staticHandler</servlet-name>
<servlet-class>com.spitter.servlet.StaticServlet</servlet-class>
<load-on-startup>5</load-on-startup>
</servlet>
<servlet>
<servlet-name>SpitterServiceEndPoint</servlet-name>
<servlet-class>com.sun.xml.ws.transport.http.servlet.WSServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>spitter</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>staticHandler</servlet-name>
<url-pattern>/resources/*</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>SpitterServiceEndPoint</servlet-name>
<url-pattern>/SpitterServiceEndPoint</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
</web-app>
I am using spring 3.0.2
My scheduled method is invoked twice..
am i making some mistake..?
please help me to figure it out..

Answer 1

Found in the documentation of spring :
Make sure that you are not initializing multiple instances of the same #Scheduled annotation class at runtime, unless you do want to schedule callbacks to each such instance. Related to this, make sure that you do not use #Configurable on bean classes which are annotated with #Scheduled and registered as regular Spring beans with the container: You would get double initialization otherwise, once through the container and once through the #Configurable aspect, with the consequence of each #Scheduled method being invoked twice.
Maybe this is the reason

Answer 2

It looks like your cron syntax is wrong - My guess is that you have typed in ? and * accidentally. You should change it to:
#Scheduled(cron="0 58 18 * SUN")
If you specify 6 parameters (like you had in your original syntax), cron expects the 6th element to be the year. SUN is a 'day of the week' parameter, and should be specified in 5th position, so cron is getting confused.