I am having circular dependency in my application. I did not get any circular dependency issue while server startup on my local setup or other 3 setups I was working on.
But, I was getting circular dependency error on server startup on production environment.
Below was the error :
Error creating bean with name 'someBean': Bean with name 'someBean' has been injected into other beans [someOtherBean] in its raw version as part of a circular reference, but has eventually been wrapped. This means that said other beans do not use the final version of the bean. This is often the result of over-eager type matching - consider using 'getBeanNamesOfType' with the 'allowEagerInit' flag turned off, for example.
when I added default-lazy-init = "true" in my application_context.xml file, error got resolved.
My question is, how come I wasn't getting any such error on my local or other setup even though I wasn't having default-lazy-init = "true" in my application_context.xml file. I came to know that the problem can be solved in several ways. But I would like to know the root cause of how spring differs in bean creation from one system to another. Or is it specific to OS or Tomcat server.
I am currently working with Heritrix and I have a standard installation (this one: http://builds.archive.org/maven2/org/archive/heritrix/heritrix/3.2.0/) and it works fine.
But now I want to write and add my own extensions e.g. change the priority of urls which should be crawled or just a simple extractor. I can inspect the java code of an existing extractor but how can I add it to the crawler?
I tried to export my java test project to a jar file and put this file in the lib folder of Heritrix (where the other libraries are). Furthermore I added a bean to my job's cxml file.
But after starting I got this error: 2014-11-07T19:51:40.296Z SEVERE Could not instantiate bean class [myModule.TestClass]: No default constructor found; nested exception is java.lang.NoSuchMethodException: myModule.TestClass.(); Can't create bean 'myModule.TestClass#0'
It is just the extractorHTML renamed and in a new project and exported to a jar file.
Any idea what is wrong? I read all the documentations but there are only explanations how to write extensions and not how to add it?
Greetings and thank you :-)
I think the issue is the class loader requires a default constructor (A constructor - which takes no arguments) Add a default constructor
public YourClass() { }
and the required getters and setters for setting the member variables.
I get this error :
Getting “Deadlock found when trying to get lock; try restarting transaction”
I'm trying to resolve it using annotation RetryTransaction with #Transactionnal.
But the annotation cannot be resolved to a type.
What is the config to set in spring-config.xml to make it work ? or maybe supplementary dependecies to install ?
Googling a bit reveals that the annotation you mentioned is not from spring, but someone else produced it.
You can get the maven artefact that contains it from here http://mvnrepository.com/artifact/org.dellroad/dellroad-stuff/1.0.659
I am confused on the usage of alias. I do understand what alias is and how it is being used but i don't see how it can be any different than using names on a bean definition.
<bean id="xyx" name="abc,def" .. />
<alias name="xyx" alias="pqr"/>
Why the alias when i can use abc or def?
In my mind bean aliasing can be helpful in large system, where you can not manipulate bean names. You have option to create your own name (alias) specific for your part of the system...
from Spring documentation (3.0.x)
http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/htmlsingle/
...it is sometimes desirable to give a single bean multiple names,
otherwise known as bean aliasing...
therefore creating multiple names or/and aliasing are the same thing.
A use case maybe when you want to customize some beans that are already defined somewhere in a modular application (each module is a spring project for example), the bean maybe defined by a third-party framework/API or even your team. In that case you want that only inside your spring project call the customized version without altering other modules (projects), to do that just add the alias in your spring configuration which is indeed a powerful feature:
<alias alias="globalBeanService" name="customizedBeanService" />
Hence, whenever spring find a call to the globalBeanService, it will inject customizedBeanService for you inside your specific module.
Without this feature, you should go through all classes and modify the bean manually!!
An aliased bean will always have higher priority over a non-aliased one, and in case of having different beans with the same alias then the last one declared will have the priority. In other words, the aliased bean will override the non-aliased beans.
This can be particularly useful when creating big projects or when you are building extensions to your project and don't want to touch the original bean definition.
Alias has a specific using scenario which multiple names don't have:
Imagine multiple config xml files in your project, most of which are authored by your colleagues, and you need to add your own config.xml file. Using you'll be able to refer to a bean defined in another config file with a different name that's maybe more meaningful to your config, without having to touch your colleagues' config files.
I recently found another use case where alias easily solved a problem.
When auto configuration is active, Spring Boot provides the bean serverProperties which can be used to access information about the server currently running the web app.
In integration tests (i.e. when #SpringBootTest annotation is present) the same bean is available under the name org.springframework.boot.autoconfigure.web.ServerProperties.
Of course it is possible to use a different profile for integration testing, but that would require manual change of configuration at multiple places. However, simply by adding
<alias name="serverProperties" alias="org.springframework.boot.autoconfigure.web.ServerProperties"/>
the same configuration files can be used for integration tests and in production.
This might be a bug in Spring Boot, however alias easily solve the problem without waiting for a new release. And most certainly I have no possibility to alter the Boot configuration myself.
I have a web-app, which loads a application-context files from many locations.
One of the application-context file is in a .jar file (this jar is present in WEB-INF/lib).
This application-context has an entry like this:
<context:property-placeholder location="classpath:META-INF/spring/default.app.properties" ignore-unresolvable="true" ignore-resource-not-found="true"/>
But the default.app.properties is never found. I keep getting errors about
Could not resolve placeholder 'db.driver' - something that is defined in default.app.properties and referred in application-context via ${db.driver}
It is almost as if property-placeholder is being ignored. I tried giving absolute path to my default.app.properties too.. even that wouldn't work.
Have you solved this problem? I've encoutered the same recently. My solution is simple and unlikely to be the case but... in my case there were two types of placeholders of different types. One type was configured using
<context:property-placeholder/>
the other type was configured as a bean of type ServletContextPropertyPlaceholderConfigurer. Removing one type of placeholder solved the problem.
Because Spring allow exist only one <context:property-placeholder/>, When Spring find a <context:property-placeholder/>,it will ignore the remains. So put all the properties conf in one place.
reference to :http://www.iteye.com/topic/1131688