I have 2 classes
public class Abcd{
private String username;
private String password;
public Abcd(#Value("${username}") String userName, #Value("${password}") String password) {
...
}
public String retrieveValues(){
......
return "someString";
}
}
public class SomeClass{
#Autowired
private Abcd obj;
public String method1(){
obj.retrieveValues();
}
I have a Xml as below.
<context:annotation-config />
<context:property-placeholder location="classpath:applNew.properties" />
<bean id="abcd" class="com.somecompany.Abcd">
<constructor-arg type="java.lang.String" value="${prop.user}" />
<constructor-arg type="java.lang.String" value="${prop.password}" />
</bean>
<bean id="someclass"
class="com.differentcompany.SomeClass">
</bean>
When I build the project and start the server, i see the below exceptions.
SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'abcd' defined in URL []: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class []: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: Superclass has no null constructors but no arguments were given
Caused by: java.lang.IllegalArgumentException: Superclass has no null constructors but no arguments were given
I dont understand what could be the issue to do a constructor injecting this way. Is there any solution for this?
Classes to be proxied by CGLIB (for AOP support) must have no-args constructors.
These no-args constructors don't have to be public and it doesn't affect anything else - you can use other constructors as usually:
public class Abcd{
// Dummy constructor for AOP
Abcd() {}
public Abcd(#Value("${username}") String userName, #Value("${password}") String password) { ... }
...
}
See also:
7.6 Proxying mechanisms
Related
I am trying to introduce a new bean to existing project
Current bean is
package w.x.y.z.pkgA
#Component
public class BeanA implements InterfaceA {
}
And I am trying to add new Bean to w.x.y.z.pkgB
package w.x.y.z.pkgB
public class BeanB implements InterfaceB {
#Autowired
private BeanA beanA
#PostConstruct
public void postConstructMethod() {
//Call some method in BeanA
}
}
From BeanB I want to access BeanA data and in BeanB post construct I want to register BeanB with BeanA. So I want to call BeanA method
And All these packages are packaged as jar
and spring context xml is
<context:annotation-config />
<context:component-scan base-package="w.x.y.z.pkgA,w.x.y.z.pkgB" />
<bean id="beanb" clas="w.x.y.z.pkgB.BeanB"></bean>
But during deployment I get exception about bean in create state
Caused by: org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'context': Requested bean is currently in creation: Is there an unresolvable circular reference?
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.beforeSingletonCreation(DefaultSingletonBeanRegistry.java:347)
at w.x.y.z.BeanA<init>(BeanA.java:25)
at w.x.y.z.BeanB.<init>(BeanB.java:35)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:147)
I have also tried removed #Autowired and getting the BeanA object using getBeanFactory().getBean(BeanA.class). But I get same error.
If I remove bean entry from xml file them it gets deployed properly but post construct is never called as it is no longer a bean.
BeanA is not dependent on BeanB at all. No references?
Is there a way to get this #Autowired and #PostConstruct to work when 2 beans are in same jar?
You declare the bean as <bean id="beanb" clas="w.x.y.z.BeanB"> from w.x.y.z package.
Try with
package w.x.y.z
#Component
public class BeanA implements InterfaceA {
}
package w.x.y.z
public class BeanB implements InterfaceB {
private BeanA beanA
#PostConstruct
public void postConstructMethod() {
//Call some method in BeanA
}
// Getters and Setters
}
and
<context:annotation-config />
<context:component-scan base-package="w.x.y.z" />
<bean id="beanb" clas="w.x.y.z.BeanB">
<property name="beanA" value="beanA"/> <!-- Spring will create beanA as it is annotated with #Component -->
</bean>
I'm currently using Spring 3 annotations along with hibernate 3 for the database connectivity. I also have to be using spring tiles.
My spring-servlet.xml is:
<context:annotation-config />
<context:component-scan base-package="com.xxx.controller,com.xxx.dao,com.xxx.service" />
<mvc:annotation-driven />
<bean class="org.springframework.web.servlet.view.UrlBasedViewResolver"
id="viewResolver">
<property name="viewClass">
<value>
org.springframework.web.servlet.view.tiles2.TilesView
</value>
</property>
</bean>
<bean class="org.springframework.web.servlet.view.tiles2.TilesConfigurer"
id="tilesConfigurer">
<property name="definitions">
<list>
<value>/WEB-INF/plugin/impl/tiles/springtiles-defs.xml</value>
</list>
</property>
</bean>
//Is this required????
<!-- <bean id="MyDAO" class="com.xxxx.MyDAOImpl"></bean>
<bean id="MyService" class="com.xxxx.MyServiceImpl"></bean> -->
My controller class :
#Controller
public class myController {
#Autowired
private MyService myService;
public myController() {
}
#RequestMapping(value="/index.do", method = RequestMethod.GET)
protected ModelAndView Submit(HttpServletRequest request, HttpServletResponse response) throws Exception {
// TODO Auto-generated method stubs
System.out.println(" Inside the controller ");
</beans>
And my serviceImpl class:
#Service("MyService")
public class MyServiceImpl implements MyService{
#Autowired
MyDAO myDAO;
And my DaoImpl class :
#Repository/*("myDAO")*/
public class MyDAOImpl implements MyDAO{
List<String> clientList;
#Autowired
private SessionFactory sessionFactory;
private Session session;
private Session currentSession() {
return this.sessionFactory.getCurrentSession();
}
#Override
public List<ClientInfoBean> getClientList(String currentQrt) throws DataStoreException {
// TODO Auto-generated method stub
return (List<ClientInfoBean>) this.currentSession().
createCriteria("Select * from myTable);
}
It still gives the below exceptions.
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'MyController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.xxx.service.MyService com.xxx.controller.MyController.MyService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.xxx.service.MyService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:288)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1116)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.xxx.service.MyService com.xxx.controller.MyController.MyService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.xxx.service.MyService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:514)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:285)
... 97 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.xxx.service.MyService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:988)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:858)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:770)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:486)
... 99 more
So the problem is your packages:
You have definition of services and daos in: com.xxx.service and com.xxx.dao
and your implementation in: com.xxx.serviceImpl and com.xxx.daoImpl.
Add in also <context:component-scan base-package="com.xxx.serviceImpl,com.xxx.daoImpl"/>
Next problem you are facing is transactional management:
You havent defined it in spring configuration. This is an example how to do this:
<!-- Hibernate 3 Annotation SessionFactory Bean definition-->
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
<prop key="hibernate.show_sql">false</prop>
<prop key="hibernate.jdbc.batch_size">${batchSize}</prop>
</props>
</property>
</bean>
<bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
And after this you need to mark a method or your service implementation as #Transactional to make spring care of this.
The exception is clearly telling you that the bean is not configured
NoSuchBeanDefinitionException: No qualifying bean of type [com.xxx.service.MyService]
Can you check the case of the bean names that you given in annotations are matching with the parameter name. myService vs MyService.
Also adding a setter might be a good idea as spring can call setter to inject the dependency instead of using Reflection to inject it.
When you define
#Service("MyService")
public class MyServiceImpl implements MyService{
}
or
#Repository("MyDAO")
public class MyDAOImpl implements MyDAO{
}
you are actually telling spring to create bean with the name "MyService" & "MyDAO"
when you define like
#Autowired
private MyService myService;
#Autowired
private MyDAO myDAO;
you are asking from spring to give bean(s) with the name "myService" & "myDAO".
Since spring creates bean with the name which is different from what are you asking, it is giving the error.
You have to keep name of the bean in the #Service & #Repository annotation same as the variable name for the Interface.
#Service("myService")
public class MyServiceImpl implements MyService{
}
private MyService myService;
As you qualified your service as "MyService" , you can add qualifier as below to find it. By default spring should autowire by type , so component scan should load your service. If you are defining beans partially in xml and expecting other services to be autowired, you have to add in your spring-servlet.xml
#Autowired
#Qualifier("MyService")
private MyService myService;
Also change your controller class as MyController instead of myController.
And remove the constructor myController(), spring will construct for you controller bean. Try to remove all your constructors in all your spring bean classes, spring will construct for you. For the beginning you can avoid qualifying the beans, remove the names in brackets( "MyService", "MyDao" etc....)
Use
#Service
public class MyServiceImpl implements MyService
Instead of
#Service("MyService")
public class MyServiceImpl implements MyService{
I have a singleton service class like the below.
#Service
public class SingletonClass{
#Autowired
private ContextProvider provider;
public Context run(){
context = provider.createContext();
updateContext(context)
}
ContextProvider class:
public abstract class ContextProvider implements MyInterface{
public abstract Context createContext();
}
configuration:
<bean name="provider"
class="xyz.s.s.ContextProvider" >
<lookup-method name="createContext"
bean="someBean" />
</bean>
<bean id="somebean" class="com.x.y.someclass" />
<bean id="singletonService" class="com.x.y.SingletonClass" />
When i try to run the above using Junit ->instead of creating the lookup bean on demand, I am getting the below error
org.springframework.beans.factory.BeanCreationException:
aused by: java.lang.AbstractMethodError
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeAwareMethods(AbstractAutowireCapableBeanFactory.java:1585)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1553)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
It seems, the lookup method injection is not working in my case
I found the issue and fixed it.
I was having the abstract class implemented an interface. So at run time,
CGLIB unable to create a proxy class since there are unimplemented methods.
Compiler also did not complain, because this is abstract class and it did not expect us to add all implementations of the interface.
I removed the 'implements ' and it just works fine.
So the contextprovider will become,
public abstract class ContextProvider {
public abstract Context createContext();
}
Posting this message, since people might face same situation.
I'm trying to inject a constructor that takes some arguments. After compiling Spring complains it couldn't find a default constructor (I haven't defined it) and throws BeanInstatiationException and NoSuchMethodException.
After defining a default constructor the exceptions don't appear anymore, however my object is never initialized with the argument constructor, only the default one is called. Does Spring really require a default constructor in this case? And if yes, how can I make it use the argument constructor instead of the default one?
This is how I wire everything:
public class Servlet {
#Autowired
private Module module;
(code that uses module...)
}
#Component
public class Module {
public Module(String arg) {}
...
}
Bean configuration:
<beans>
<bean id="module" class="com.client.Module">
<constructor-arg type="java.lang.String" index="0">
<value>Text</value>
</constructor-arg>
</bean>
...
</beans>
Stack trace:
WARNING: Could not get url for /javax/servlet/resources/j2ee_web_services_1_1.xsd
ERROR initWebApplicationContext, Context initialization failed
[tomcat:launch] org.springframework.beans.factory.BeanCreationException: Error
creating bean with name 'module' defined in URL [...]: Instantiation of bean failed;
nested exception is org.springframework.beans.BeanInstantiationException: Could not
instantiate bean class [com.client.Module]: No default constructor found; nested
exception is java.lang.NoSuchMethodException: com.client.Module.<init>()
Spring only "requires" a default constructor if you plan on instantiating it without any arguments.
for example, if your class is like this;
public class MyClass {
private String something;
public MyClass(String something) {
this.something = something;
}
public void setSomething(String something) {
this.something = something;
}
}
and you set it up in Spring like this;
<bean id="myClass" class="foo.bar.MyClass">
<property name="something" value="hello"/>
</bean>
you're going to get an error. the reason is that Spring instantiates your class new MyClass() then tries to set call setSomething(..).
so instead, the Spring xml should look like this;
<bean id="myClass" class="foo.bar.MyClass">
<constructor-arg value="hello"/>
</bean>
so have a look at your com.client.Module and see how its configured in your Spring xml
Most probably you are using component-scanning and since you define annotation #Component for class Module it tries to instantiate the bean. You do not need #Component annotation if You are using XML for bean definition.
Just faced the same problem, i guess till now you might have solved the problem.
Below is what you could have changed your bean configuration to,
<bean id="module" class="com.client.Module">
<constructor-arg value="Text"/>
</bean>
Session object's autowired properties do not autowire if the session object is declared
<bean id="user" class="org.User" scope="session">
<aop:scoped-proxy/>
</bean>
The user objects proerty is #autowired but the property doesn't get autowired.
public class User
{
TemplateService templateService;
#Autowired
public void setTemplateService(TemplateService templateService) {
this.templateService = templateService;
}
}
I wonder why this is so.
Is replacing the autowire annotations with xml declarations the only solution. Are there any other solutions?
Thanks