in Spring MVC we can configure handler mapping as bean.but how spring examine what is the handler mapping we mentioned in xml?
simpliy
<bean id="simplehandler" class="" />
do we need to specify "simplehandler" bean id to somewhere for spring to identify bean handler?
First thing that must be clear is that: Spring has several handler mappings.
And the "DefaulAnnotationHandlerMapping" is activated by default (See DispatcherServlet.properties in the Spring distribution or just google for it. All default handlers are listed there). Spring will choose "DefaulAnnotationHandlerMapping" by default.
If you want Spring to use another handler mapping strategy, you have to tell him explicitly
e.g.:
<bean class="org.blablabla......ControllerClassNameHandlerMapping" />
Note that this cancels the use of the default handler mapping strategy
You can also tell Spring to use several handler mapping strategy and prioritized them by using the order property in the mappers declaration
something like
<bean class="org.blabla....DefaulAnnotationHandlerMapping" >
<property name="order" value="0"/>
</bean>
<bean class="org.blablabla......ControllerClassNameHandlerMapping">
<property name="order" value="1"/>
</bean>
Hope this helps. And sorry if the syntax of my bean declaration is not 100% correct. I had to write quickly ;-)
Related
As I am planning to update from "hibernate3" to "hibernate4" & "spring 3.0.5" to "spring 3.1.4".
I have configured OpenSessionInViewInterceptor in spring 3.0.5 so want to configure same in 3.1.4.
But I am not able to configure flushMode in OpenSessionInViewInterceptor of Spring 3.1.4;
My Previous setting for spring 3.0.5 was:
<bean name="openSessionInViewInterceptor"
class="org.springframework.orm.hibernate3.support.OpenSessionInViewInterceptor">
<property name="sessionFactory">
<ref bean="sessionFactory" />
</property>
<property name="flushMode">
<bean
id="org.springframework.orm.hibernate3.HibernateAccessor.FLUSH_NEVER"
class="org.springframework.beans.factory.config.FieldRetrievingFactoryBean" />
</property>
</bean>
Now tried to configure same for spring 3.1.4 as below:
<bean name="openSessionInViewInterceptor"
class="org.springframework.orm.hibernate4.support.OpenSessionInViewInterceptor">
<property name="sessionFactory">
<ref bean="sessionFactory" />
</property>
<property name="flushMode">
<bean
id="org.springframework.orm.hibernate3.HibernateAccessor.FLUSH_NEVER"
class="org.springframework.beans.factory.config.FieldRetrievingFactoryBean" />
</property>
</bean>
then it throws below exception:
org.springframework.beans.NotWritablePropertyException: Invalid property 'flushMode' of bean class [org.springframework.orm.hibernate4.support.OpenSessionInViewInterceptor]: Bean property 'flushMode' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?
And there is no similar class found in alternate to org.springframework.orm.hibernate3.HibernateAccessor in spring 3.1.4
So my question is how to set flushMode property of OpenSessionInViewInterceptor of spring 3.1.4 ?
It looks like a mess, with unbound links to property accessors. I'd guess that a copy-paste job was done without much thinking about cleaning things up given the different inheritance hierarchies. I hate it when that happens…
Can you use the Hibernate 3 version instead? Yes, it really does appear to be there; here's the link: org.springframework.orm.hibernate3.support.OpenSessionInViewInterceptor
Longer term, look more carefully whether the Hibernate 4 code does what you want without specifying the flag at all. Unfortunately, you'll have to ignore the documentation (at least for now) and study the source itself.
I have next applicationContext.xml file on the root of classpath:
<context:annotation-config />
<context:property-placeholder location="classpath:props/datasource.properties" />
<bean id="datasource" class="org.apache.commons.dbcp.BasicDataSource"
p:username="${jdbc.username}"
p:password="${jdbc.password}"
p:url="${jdbc.url}"
p:driverClassName="${jdbc.driverclass}"
p:validationQuery="SELECT sysdate FROM dual" />
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"
p:dataSource-ref="datasource"
p:mapperLocations="classpath:mappers/*-mapper.xml" />
<tx:annotation-driven transaction-manager="txManager" />
<bean id="txManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
p:dataSource-ref="datasource" />
<bean id="mappeScannerConfigurere" class="org.mybatis.spring.mapper.MapperScannerConfigurer"
p:sqlSessionFactory-ref="sqlSessionFactory"
p:basePackage="com.mypackage" />
props/datasource.properties also exists on the root of classpath with such content:
jdbc.url=myjdbcurl
jdbc.driverclass=myClass
jdbc.username=myUserName
jdbc.password=myPassword
I have a spring managed test where I declare to use previously mentioned applicationContext.xml via next annotations:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations = {"classpath:applicationContext.xml"})
When I invoke test method i get next error from spring:
org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class '${jdbc.driverclass}'
As I understand sping didn't resolve reference to jdbc.driverclass.
What have I done wrong?
PS: I'm using spring 3.2.3.RELEASE
**
EDIT
**
Perhaps the problem may be in MapperScannerConfigurer. It is a BeanDefinitionRegistryPostProcessor and as Javadoc says:
Extension to the standard BeanFactoryPostProcessor SPI,
allowing for the registration of further bean definitions
before regular BeanFactoryPostProcessor detection kicks in
So MapperScannerConfigurer instantiates datasource object via sqlSessionFactory with BeanFacoryPostProcessor(which is responsible for <context:property-placeholder/>) have not been utilized.
So my question transforms to how to reorder BeanFacoryPostProcessor from <context:property-placeholder/> and BeanDefinitionRegistryPostProcessor(MapperScannerConfigurer)?
Resolved
After a couple hours of investigation I found the solution:
As I said earlier MapperScannerConfigurer is a BeanDefinitionRegistryPostProcessor which fires before BeanFactoryPostProcessor which is responsible for <context:property-placeholder/>. So, during the creation of MapperScannerConfigurer references to external properties will not be resolved. In this case we have to defer the creation of datasource to the time after BeanFactoryPostProcessorhave been applied. We can do that in several ways:
remove p:sqlSessionFactory-ref="sqlSessionFactory" from MapperScannerConfigurer. In this case datasource object will not be created before MapperScannerConfigurer, but after BeanFactoryPostProcessor which is responsible for <context:property-placeholder/>. If you have more than one sqlSessionFactory in applicationContext, than can be some troubles
In versions of mybatis-spring module higher than 1.0.2 there is a possibility to set sqlSessionFactoryBeanName instead of sqlSessionFactory. It helps to resolve PropertyPlaceHolder issue with BeanFactoryPostProcessor. It is a recommended way to solve this issue described in mybatis-spring doc
I was having the same issue and came across this post but I was unable to resolve it the same way maks did. What ended up working for me was to set the ignoreUnresolvablePlaceholders property value to true.
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location">
<value>classpath:database.properties</value>
</property>
<property name="ignoreUnresolvablePlaceholders" value="true"/>
</bean>
I am using Spring 3.2.3.RELEASE as well. I realize this post is over 4 months old but I figured someone might find it useful.
Short form: What is the proper way to load an implementation of: BeanDefinitionRegistryPostProcessor?
Expanded form: Is there a way to load BeanDefinitionRegistryPostProcessor before any beans have been created. If you look at the javadoc:
Extension to the standard {#link BeanFactoryPostProcessor} SPI, allowing for
the registration of further bean definitions before regular
BeanFactoryPostProcessor detection kicks in.
So it's meant to be loaded when bean definitions have been created but before any beans have been created. If we just create it as a regular bean in the application xml then it defeats the purpose of having this bean in the first place.
Spring web flow provides additional bean scopes like flow, conversation, flash etc. I can define flow scope beans in flow.xml using var or i can set values to new scoped variables. How i can define it in spring application context xml file. I tried to use this pattern:
<bean id="abc" class="abc" scope="flow"/>
I got error that no scope defined. I searched on google and found this thing
http://blog.springsource.org/2007/05/08/spring-web-flow-bean-scopes-and-jsf/
but don't know how to enable it in spring web flow 2.3
try to define it in your application context:
<bean class="org.springframework.beans.factory.config.CustomScopeConfigurer">
<property name="scopes">
<map>
<entry key="flow">
<bean class="org.springframework.webflow.config.scope.FlowScope"/>
</entry>
</map>
</property>
</bean>
Why is autowiring required? What is the explanation for the concept of autowiring?
#autowired annotation in Spring Framework.
Autowiring is not required, just convenient.
It means that if you have a property that requires an InterfaceA and a single bean has been declared in Spring that is of type InterfaceA, instead of using XML to manually "wire up" the relationship (setting a bean reference as a property of another), you can let Spring do the wiring for you.
This is a common question for the beginners. As the beans are injected using DI (setter injections, constructor injections), why do we need auto-wiring? Auto-wiring also doing the same thing, right?
The answer is, it saves you from writing more code.
If using an XML file, using autowire attribute saves you from writing the wiring code in the bean definition.
Please look at code below.
Configuration code without Auto-wiring:
<bean id="employee" class="com.Employee">
<property name="name" value="Dexter"></property>
</bean>
<bean id="employeeService" class="com.EmployeeService">
<property name="employee" ref="employee"></property>
</bean>
Configuration code with Auto-wiring:
<bean id="employee" class="com.Employee">
<property name="name" value="Dexter"></property>
</bean>
<bean id="employeeService" class="com.EmployeeService" autowire="byName" />
Note that we did not have to write anything to refer property of EmployeeService, i.e., Employee. But still it was injected. Autowiring makes the container to search the bean configurations and do the collaboration among beans, without the developer specifically mentioning these.
If we use annotation, even we don’t have to write anything in XML files, including this autoware="byName", etc. Simply #Autowired on bean's setter/field/constructor is sufficient.
I'm switching from faces-config to Spring and wanted to know how you can pass a property from one bean to another:
e.g.
<bean id="myBean" class="Bean1">
</bean>
<bean id="myBean2" class="Bean2">
<constructor-arg ref="#{myBean1.value}"/>
</bean>
Upgraded to Spring 3.0 which has spring el support
First things first, the purpose of the D.I container is to fully initialize your system prior to execution; that is, all dependencies being set, the app is ready to run.
There are both #property and #value annotations in Spring for similar purposes, but since you want to use and specific bean property value for other bean the best solution would be:
<bean id="myBean" class="Bean1">
</bean>
<bean id="myBean2" class="Bean2">
<constructor-arg ref="myBean"/>
</bean>
If you argue that you just want to set the value at instantiation time, and not establish a dependency, then skip the D.I part and set the value directly.