send message to activemq in mvc spring give null pointer exception - spring-mvc

Question

I am try to execute sample send and recive message to/from activemq by mvc spring But when I Run the project I get this error :
java.lang.NullPointerException
com.sarf.jms.MessageProducerBean.sendMessage(MessageProducerBean.java:24)
com.sarf.testactimq.HomeController.home(HomeController.java:42)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:497)
org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:213)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:126)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:96)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:617)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:578)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
My source code :
MessageObject.java :
package com.sarf.data;
public class MessageObject {
private String mailId;
private String message;
public MessageObject(){};
public MessageObject(String mailId, String message) {
super();
this.mailId = mailId;
this.message = message;
}
public String getMailId() {
return mailId;
}
public void setMailId(String mailId) {
this.mailId = mailId;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
}
MessageConsumerBean.java :
package com.sarf.jms;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MapMessage;
import org.springframework.jms.core.JmsTemplate;
import org.springframework.jms.support.JmsUtils;
import com.sarf.data.MessageObject;
public class MessageConsumerBean{
private JmsTemplate jmsTemplate;
private Destination destination;
public void setJmsTemplate(JmsTemplate jmsTemplate) {
this.jmsTemplate = jmsTemplate;
}
public void setDestination(Destination destination) {
this.destination = destination;
}
public MessageObject receiveMessage() {
MapMessage message = (MapMessage) jmsTemplate.receive(destination);
try {
MessageObject messageObj = new MessageObject();
messageObj.setMailId(message.getString("mailId"));
messageObj.setMessage(message.getString("message"));
return messageObj;
} catch (JMSException e) {
throw JmsUtils.convertJmsAccessException(e);
}
}
}
MessageProducerBean.java :
package com.sarf.jms;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MapMessage;
import javax.jms.Message;
import javax.jms.Session;
import org.springframework.jms.core.JmsTemplate;
import org.springframework.jms.core.MessageCreator;
import com.sarf.data.MessageObject;
public class MessageProducerBean {
//JMS Template object
private JmsTemplate jmsTemplate;
private Destination destination;
public void setJmsTemplate(JmsTemplate jmsTemplate) {
this.jmsTemplate = jmsTemplate;
}
public void setDestination(Destination destination) {
this.destination = destination;
}
public void sendMessage(final MessageObject messageObj) {
jmsTemplate.send(destination, new MessageCreator() {
public Message createMessage(Session session) throws JMSException {
MapMessage message = session.createMapMessage();
message.setString("mailId", messageObj.getMailId());
message.setString("message", messageObj.getMessage());
return message;
}
}); //send method close here
}//method ends here
}
Homecontroller :
package com.sarf.testactimq;
import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.sarf.data.MessageObject;
import com.sarf.jms.MessageProducerBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.sarf.jms.*;
/**
* Handles requests for the application home page.
*/
#Controller
public class HomeController {
private static final Logger logger = LoggerFactory.getLogger(HomeController.class);
/**
* Simply selects the home view to render by returning its name.
*/
#RequestMapping(value = "/", method = RequestMethod.GET)
public String home(Locale locale, Model model) {
logger.info("Welcome home! The client locale is {}.", locale);
Date date = new Date();
DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, locale);
String formattedDate = dateFormat.format(date);
model.addAttribute("serverTime", formattedDate );
MessageProducerBean mp = new MessageProducerBean();
mp.sendMessage(new MessageObject("1234", "Test Message"));
/*
MessageConsumerBean mc = new MessageConsumerBean();
MessageObject messageObj = mc.receiveMessage();
System.out.println("Message from " +
messageObj.getMailId() + " received");
*/
return "home";
}
}
servlete_context.xml :
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->
<!-- Enables the Spring MVC #Controller programming model -->
<annotation-driven />
<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
<resources mapping="/resources/**" location="/resources/" />
<!-- Resolves views selected for rendering by #Controllers to .jsp resources in the /WEB-INF/views directory -->
<beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<beans:property name="prefix" value="/WEB-INF/views/" />
<beans:property name="suffix" value=".jsp" />
</beans:bean>
<beans:bean id="connectionFactory"
class="org.apache.activemq.ActiveMQConnectionFactory">
<beans:property name="brokerURL" value="tcp://localhost:61616" />
</beans:bean>
<beans:bean id="mailDestination"
class="org.apache.activemq.command.ActiveMQQueue">
<beans:constructor-arg value="mail.queue" />
</beans:bean>
<beans:bean id="jmsTemplate"
class="org.springframework.jms.core.JmsTemplate">
<beans:property name="connectionFactory" ref="connectionFactory" />
</beans:bean>
<beans:bean id="producer"
class="com.sarf.jms.MessageProducerBean">
<beans:property name="destination" ref="mailDestination" />
<beans:property name="jmsTemplate" ref="jmsTemplate" />
</beans:bean>
<beans:bean id="consumer"
class="com.sarf.jms.MessageConsumerBean">
<beans:property name="destination" ref="mailDestination" />
<beans:property name="jmsTemplate" ref="jmsTemplate" />
</beans:bean>
<context:component-scan base-package="com.sarf.testactimq" />
</beans:beans>
root_context.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"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<!-- Root Context: defines shared resources visible to all other web components -->
<bean id="connectionFactory"
class="org.apache.activemq.ActiveMQConnectionFactory">
<property name="brokerURL" value="tcp://localhost:61616" />
</bean>
<bean id="mailDestination"
class="org.apache.activemq.command.ActiveMQQueue">
<constructor-arg value="mail.queue" />
</bean>
<bean id="jmsTemplate"
class="org.springframework.jms.core.JmsTemplate">
<property name="connectionFactory" ref="connectionFactory" />
</bean>
<bean id="producer"
class="com.sarf.jms.MessageProducerBean">
<property name="destination" ref="mailDestination" />
<property name="jmsTemplate" ref="jmsTemplate" />
</bean>
<bean id="consumer"
class="com.sarf.jms.MessageConsumerBean">
<property name="destination" ref="mailDestination" />
<property name="jmsTemplate" ref="jmsTemplate" />
</bean>
</beans>
pom.xml :
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.sarf</groupId>
<artifactId>testactimq</artifactId>
<name>testmessage</name>
<packaging>war</packaging>
<version>1.0.0-BUILD-SNAPSHOT</version>
<properties>
<java-version>1.6</java-version>
<org.springframework-version>3.1.1.RELEASE</org.springframework-version>
<org.aspectj-version>1.6.10</org.aspectj-version>
<org.slf4j-version>1.6.6</org.slf4j-version>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.activemq</groupId>
<artifactId>activemq-all</artifactId>
<version>5.13.3</version>
</dependency>
<!-- Spring -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${org.springframework-version}</version>
<exclusions>
<!-- Exclude Commons Logging in favor of SLF4j -->
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${org.springframework-version}</version>
</dependency>
<!-- AspectJ -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>${org.aspectj-version}</version>
</dependency>
<!-- Logging -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${org.slf4j-version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
<version>${org.slf4j-version}</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${org.slf4j-version}</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.15</version>
<exclusions>
<exclusion>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
</exclusion>
<exclusion>
<groupId>javax.jms</groupId>
<artifactId>jms</artifactId>
</exclusion>
<exclusion>
<groupId>com.sun.jdmk</groupId>
<artifactId>jmxtools</artifactId>
</exclusion>
<exclusion>
<groupId>com.sun.jmx</groupId>
<artifactId>jmxri</artifactId>
</exclusion>
</exclusions>
<scope>runtime</scope>
</dependency>
<!-- #Inject -->
<dependency>
<groupId>javax.inject</groupId>
<artifactId>javax.inject</artifactId>
<version>1</version>
</dependency>
<!-- Servlet -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<!-- Test -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.7</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.9</version>
<configuration>
<additionalProjectnatures>
<projectnature>org.springframework.ide.eclipse.core.springnature</projectnature>
</additionalProjectnatures>
<additionalBuildcommands>
<buildcommand>org.springframework.ide.eclipse.core.springbuilder</buildcommand>
</additionalBuildcommands>
<downloadSources>true</downloadSources>
<downloadJavadocs>true</downloadJavadocs>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.5.1</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
<compilerArgument>-Xlint:all</compilerArgument>
<showWarnings>true</showWarnings>
<showDeprecation>true</showDeprecation>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.2.1</version>
<configuration>
<mainClass>org.test.int1.Main</mainClass>
</configuration>
</plugin>
</plugins>
</build>
</project>
the error in run time caused by call the methode sendMessage which define in MessageProducerBean called in my controller , I run my activemq as image shown below :
Note :I am using spring suite tool with tc server and activemq version 5.13.3
so what wrong I am doing any help ?

Answer 1

In HomeController you are creating the MessageProducerBean like so:
MessageProducerBean mp = new MessageProducerBean();
And then immediately using the MessageProducerBean to send a message:
mp.sendMessage(new MessageObject("1234", "Test Message"));
However, at this point MessageProducerBean is attempting to use the jmsTemplate variable which you haven't initialized so it's null. Hence you receive a java.lang.NullPointerException.