Tag Archives: Spring

java.lang.IllegalStateException: Web app root system property already set to different value: ‘webapp.root’ = [/ApplicationPath1] instead of [/ApplicationPath2] – Choose unique values for the ‘webAppRootKey’ context-param in your web.xml files!

Recently I have deployed two J2EE web application in tomcat web server. Both application uses the log4j. Tomcat server is up and running with no issues.

But at regular interval, one of the J2EE web application was going down. I was digging into the logs and google to find the solution. At regular times, it made us to enter into the tomcat manager page to start the application manually which was down.

Then I have identified the following exception message

java.lang.IllegalStateException: Web app root system property already set to different value: 'webapp.root' = [C:\Program Files\Apache Software Foundation\Tomcat7.0.57\webapps\application1\] instead of [C:\Program Files\Apache Software Foundation\Tomcat7.0.57\webapps\application2\] - Choose unique values for the 'webAppRootKey' context-param in your web.xml files!
at org.springframework.web.util.WebUtils.setWebAppRootSystemProperty(WebUtils.java:156)
at org.springframework.web.util.Log4jWebConfigurer.initLogging(Log4jWebConfigurer.java:117)
at org.springframework.web.util.Log4jConfigListener.contextInitialized(Log4jConfigListener.java:46)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4994)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5492)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:649)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1245)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1895)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

Root cause:

Due to the business requirement, we copied the application1’s code base and created the application2’s code base.
I gave unique names wherever necessary in the configuration files. But still I encountered the above error message. After spending long time, I got the below information about the spring framework

“WARNING: Some containers (like Tomcat) do not keep system properties separate per web app. You have to use unique “webAppRootKey” context-params per web app then, to avoid clashes. Other containers like Resin do isolate each web app’s system properties: Here you can use the default key (i.e. no “webAppRootKey” context-param at all) without worrying. ”

It turns out that the webAppRootKey is a Spring context parameter. It exposes the web application’s root directory as a system property. So, it is the value of the webAppRootKey that provides the name for the system property to use. That’s fine if you’ve just got one webapp in Tomcat. Spring will just choose a default value for this (app.root) and off you go. However, as the warning above notes, Tomcat does not keep system properties separate per webApp. This means that when we get to the second application, the same system property (app.root) is being set to a new value (our second application’s root directory, rather than the first!)

The reason this is occurring at all is that Log4JConfigListener is trying to set the webAppRootKey in both cases. This allows log4J to place log and config files in directories relative to the application root directory, rather than in a fixed path.

I decided the easiest thing was just to use a non-default name for the webAppRootKey for each of my applications.

That is, I fixed this by placing the following context-parameter into each of the web application’s web.xml files:

<code><context-param>
<param-name>webAppRootKey</param-name>
<param-value>uniqueAppRootNamee</param-value>
</context-param></code>

This fixed the problem

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org.hibernate.HibernateException: No Session found for current thread

I was integrating the Spring and Hibernate on a web application. While do so, I end up with the hibernate exception as follows,

org.hibernate.HibernateException: No Session found for current thread

Solution

First we need to understand that the getCurrentSession() only makes sense inside a scope of transaction. We need to declare an appropriate transaction manager, demarcate boundaries of transaction and perform data access inside it. For example, as follows:

<tx:annotation-driven transaction-manager="hibernateTransactionManager"></tx:annotation-driven>

<bean class="org.springframework.orm.hibernate4.HibernateTransactionManager" id="hibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"></property>
</bean>

<bean class="org.springframework.orm.hibernate4.LocalSessionFactoryBean" id="sessionFactory">
<property name="dataSource" ref="dataSource"></property>
<property name="annotatedClasses">
<list>
<value>com.saravanansivaji.model.Employee</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto} </prop>
</props>
</property>
</bean>

<bean class="org.springframework.jdbc.datasource.DriverManagerDataSource" id="dataSource">
<property name="driverClassName" value="${database.driver}"></property>
<property name="url" value="${database.url}"></property>
<property name="username" value="${database.user}"></property>
<property name="password" value="${database.password}"></property>
</bean>

At the service and DAO classes, the getSession() method only makes sense inside a scope of transaction, If you are trying to get sessionFactory.getCurrentSession() without defining your class in transactional scope then you will get above exception because getCurrentSession() can be use only in transactional scope. Please make your class transaction using @Transactional annnotation


@Service("employeeService")
@Transactional(propagation = Propagation.SUPPORTS, readOnly = true)
public class EmployeeServiceImpl implements EmployeeService {
@Autowired
private EmployeeDao employeeDao;

@Override
@Transactional(readOnly = false)
public List listEmployees() {
return employeeDao.listEmployees();
}
}

And from my DAO class EmployeeDao.java

public List listEmployees() {
try {
return (List) sessionFactory.getCurrentSession().createCriteria(Employee.class).list();
}catch(Exception e) {
System.out.println(e);
return null;
}
}

only looks for @Transactional on beans in the same application context it is defined in. This means that, if you put in a WebApplicationContext for a DispatcherServlet, it only checks for @Transactional beans in your controllers, and not your services.

Cannot find the declaration of element ‘beans’.


org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 11 in XML document from ServletContext resource [/WEB-INF/config/sdnext-servlet.xml] is invalid; nested exception is org.xml.sax.SAXParseException; lineNumber: 11; columnNumber: 64; cvc-elt.1: Cannot find the declaration of element 'beans'.
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:396)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:334)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:302)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:174)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:209)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:180)
at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:125)
at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:94)
at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:131)
at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:537)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:451)
at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:647)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:598)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:661)
at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:517)
at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:458)
at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:138)
at javax.servlet.GenericServlet.init(GenericServlet.java:158)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1284)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1197)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1087)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5229)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5516)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.xml.sax.SAXParseException; lineNumber: 11; columnNumber: 64; cvc-elt.1: Cannot find the declaration of element 'beans'.
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.handleStartElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.startElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl$NSContentDriver.scanRootElementHook(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(Unknown Source)
at org.springframework.beans.factory.xml.DefaultDocumentLoader.loadDocument(DefaultDocumentLoader.java:75)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:388)
... 29 more

Solution

First make sure that your spring library version matches with the XSD version.

For example, here I have used the spring version 3.2.0, so I have used spring XSD of 3.2 version as shown below


<beans xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.springframework.org/schema/beans"
xsi:schemalocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">

So now, the XSD version and the spring version both matches. Still the issue persist? Then, we need to open our eyes to find any typo error. So from the above ‘beans’ xsd definition, there is a typo error

The problem is with my definition of xsi:schemalocation the typo is with the L It is supposed to be capital, only then would it recognize the tag.

Change the xsi:schemalocation to xsi:schemaLocation

<beans xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.springframework.org/schema/beans"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.2.xsd" >

Happy Learning 🙂

Spring – Setter Dependency Injection

Here I show how spring container during run-time injects the value to a variable with reference from spring configuration file. We use setters and getters to be created for spring container to achieve that.

Setter Dependency Injection

Circle.java

public class Circle {

@Description("The value to this variable will be injected "
+ "by Spring container during runtime with reference from configuration file")
private String type;

public String getType() {
return type;
}

public void setType(String type) {
this.type = type;
}

public void draw() {
System.out.println(getType() + " circle drawn!!");
}
}

Spring.xml configuration file

<beans>
<!– Setter Dependency Injection Demo –>
<bean id=”circle” class=”com.saravanansivaji.spring.Circle”>
<property name=”typevalue=”Eclipse”></property>
</bean>
</beans>

Application class SpringDI.java

public class SpringDI {

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
@Description("Setter Dependency Injection Demo")
Circle circle = (Circle) context.getBean("circle");
circle.draw();
}
}

Output

Eclipse circle drawn!!

Thanks!!