I want to get the changed key value from properties file at runtime.
test.properties file:
name = Hi
I have made Thread sleep with 5 sec and changed the key value as "Hello" but it is not getting changed.
<bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:test.properties</value>
</list>
</property>
<property name="ignoreResourceNotFound" value="true" />
<property name="ignoreUnresolvablePlaceholders" value="true" />
</bean>
<bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basenames">
<list>
<value>classpath:test</value>
</list>
</property>
<property name="cacheSeconds" value="1" />
</bean>
<bean id="tempBean" name="tempBean1" class="org.sri.spring.temp.Temp"
lazy-init="false" scope="prototype">
<constructor-arg type="String" value="${name}" />
</bean>
The ${name} placeholder inside the XML configuration is resolved using the PropertySourcesPlaceholderConfigurer which, as you may notice, has nothing in common with your reloadable messageSource.
It wouldn't work either way because Spring instantiates the tempBean only once: on application startup, by passing the value of ${name} to the constructor. The bean itself is not aware of where the value came from (and in particular, it doesn't care if the properties file gets edited).
If you really think it's a good idea to do it†, you can inject the entire messageSource into your tempBean, and get the current value in each call, e.g.:
public class Temp {
#Autowired // or wired in XML, constructor, etc.
private MessageSource messages;
public String sayHello() {
return messages.getMessage("name", null, Locale.getDefault());
}
}
† injecting a configuration-related object makes testing more difficult and is arguably bad design (mixing concerns). Have a look at the Spring Cloud Config project as it's likely that this is how the future is going to look like.
I do not think that Spring will update already existing beans when the properties change.
Try to create a new bean (prototype scope)
Related
I have the following definition in my configuration:
<bean class="com.project.TimerBean">
<property name="delay" value="30000" />
<property name="interval" value="60000" />
<property name="invokeThis" value="com.project.TargetClass" />
<property name="receiver" value="XYZ" />
<property name="args" value="#{interval}" />
</bean>
I would like to set the value of args to the same value as interval (in this case, 60000) without having to hard-code the value. However, the above snippet doesn't seem to work. How should I change this?
# syntax (Spel Expressions) are supposed to work the way you wrote it. You need to replace
#{interval} to #{beanId.interval}.
For example, if the id of the bean you are creating is timerBean, #{timerBean.interval} is supposed to work. You cannot refer to a property directly even if it is a part of the bean definition.
It only works if the property you are referring to is a part of another bean.
<bean id="beanA" class="org.BeanA">
<property name="prop1" value="1000" />
</bean>
<bean id="beanB" class="org.BeanB">
<property name="prop2" value = "#{beanA.prop1}" />
<property name="prop3" value = "#{beanB.prop2}" />
</bean>
In the above example, prop2 gets initialised from prop1 correctly. But prop3 gets initialised to null.
If you look at AbstractAutowireCapableBeanFactory class and method,
protected void applyPropertyValues(String beanName, BeanDefinition mbd, BeanWrapper bw, PropertyValues pvs)
you can see that all the property values in a single bean definition are looped over and values are parsed. After all the values have been successfully parsed, only then they are set on the bean instance. In the above beanA and beanB example when prop3's value is getting parsed, spring looks for the value of prop2 on beanB which is not yet set and hence returns null.
AFAIK, there is no way around this except the way suggested by #Alex
PS: I am using spring version 4.1.6.RELEASE
Move interval value "60000" to the property file
yourVariableName = 60000
and change to:
<property name="interval" value="${yourVariableName}" />
<property name="args" value="${yourVariableName}" />
I want to resolve a property and specify the name of the property using a Spel expression. If I do this
<property name="host" value="#{T(...Constants).SINK_PROP_HOST}" />
the value gets resolved correctly to sink.host which is the value of this constant. Taking it a step further
<property name="host" value="${#{T(...Constants).SINK_PROP_HOST}}" />
This doesn't works. Any ideas how I can make it work. Essentially it should function the same as
<property name="host" value="${sink.host}" />
You can't do that, because properties are resolved before SpEL (you can do it the other way around).
This works...
public class Foo {
public static final String FOO = "foo.prop";
}
<util:properties id="props">
<prop key="foo.prop">bar</prop>
</util:properties>
<bean id="xx" class="foo.Bar">
<property name="foo" value="#{props[T(foo.Foo).FOO]}"/>
</bean>
You can, of course, load your "props" bean from a file.
I am trying to inject the aspects in a service. For this service I am creating a proxied object using classic way.
I have written a bean- baseProxy of type (ProxyFactoryBean) which contains a list of all the required advices.
<bean id="baseProxy" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="interceptorNames">
<list>
<value>methodInvocationAdvice</value>
</list>
</property>
</bean>
I am creating a proxy for the service like this :
<bean id="singproxy" parent="baseProxy">
<property name="target" ref="singtarget" />
<property name="targetClass" value="com.spring.learning.SingingService"></property>
</bean>
Which doesn't work but when I revert these two properties and write like this :
<bean id="singproxy" parent="baseProxy">
<property name="targetClass" value="com.spring.learning.SingingService"></property>
<property name="target" ref="singtarget" />
</bean>
To my surprise it works fine. In spring does it matter on the order for bean ? Or its a special case with ProxyFactoryBean?
I tried with Spring 3.0 I am not sure same behavior exists with previous versions.
Concerning target and targetClass, It's one or the other, but not both. Here's the relevant source (from org.springframework.aop.framework.AdvisedSupport), a parent class of ProxyFactoryBean:
public void setTarget(Object target) {
setTargetSource(new SingletonTargetSource(target));
}
public void setTargetSource(TargetSource targetSource) {
this.targetSource = (targetSource != null ? targetSource : EMPTY_TARGET_SOURCE);
}
public void setTargetClass(Class targetClass) {
this.targetSource = EmptyTargetSource.forClass(targetClass);
}
As you can see, both setTarget() and setTargetClass() write to the same field, so the last assignment wins.
My messages.properties is really a big file.
So, I tried moving some of the properties in messages.properties to a new file, say newmessages.properties and updated spring bean configuration xml with both the files as follows:
<bean id="messageSource"
class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename" value="classpath:i18n/messages"/>
<property name="defaultEncoding" value="UTF-8"/>
</bean>
<bean id="anotherMessageSource"
class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename" value="classpath:i18n/newmessages"/>
<property name="defaultEncoding" value="UTF-8"/>
</bean>
But, I am not able access any properties defined in the new property file.
Is it really possible to specify multiple property files(for a single locale)?
The basenames (s at the end) property accept an array of basenames:
Set an array of basenames, each following the above-mentioned special convention. The associated resource bundles will be checked sequentially when resolving a message code.
#see java doc: ReloadableResourceBundleMessageSource.setBasenames
So you should have only one messages source, with a list files (try to seperatate them by comma).
<bean id="anotherMessageSource"
class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basenames" value="classpath:i18n/newmessages,classpath:i18n/messages"/>
<property name="defaultEncoding" value="UTF-8"/>
</bean>
Another clean way to doing same:
<bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basenames">
<list>
<value>classpath:messages1</value>
<value>classpath:messages2</value>
</list>
</property>
<property name="defaultEncoding" value="UTF-8"/>
</bean>
Alternative solution to those already mentioned would be using the property parentMessageSource that delegates the message lookup to the parent if it does not find it in the current instance.
In your case it is probably better to stay with the basenames array. Having the hierarchic message source could make more sense if the message sources were using different implementations. E.g. the second one reading messages from db.
Note that in this case, when Spring finds two instances of MessageSource, so the primary one will be the one with the id messageSource.
<bean id="messageSource"
class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="parentMessageSource"><ref bean="anotherMessageSource"/></property>
<property name="basename" value="classpath:i18n/messages"/>
<property name="defaultEncoding" value="UTF-8"/>
</bean>
<bean id="anotherMessageSource"
class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename" value="classpath:i18n/newmessages"/>
<property name="defaultEncoding" value="UTF-8"/>
</bean>
For those(like me), looking for java config solution :
#Bean
public MessageSource messageSource() {
ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
messageSource.setBasenames("i18n/messages", "i18n/newmessages");
return messageSource;
}
jdoc : http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/context/support/AbstractResourceBasedMessageSource.html#setBasenames-java.lang.String...-
I've successfully loaded multiple messages properties into a spring boot application with following bean configuration.
#Bean
public MessageSource messageSource() {
ReloadableResourceBundleMessageSource messageSource
= new ReloadableResourceBundleMessageSource();
messageSource.setBasenames("classpath:/messages/exception/messages",
"classpath:/messages/response/messages");
messageSource.setDefaultEncoding("UTF-8");
return messageSource;
}
I have a string property which looks similar to the following example:
<property name="mappingData">
<list>
<bean class="com.company.product.longNamingStandard.migration.extractor.FieldMapping">
<property name="elementName" value="entitlement.user"/>
<property name="mapping" value="DocUsers"/>
</bean>
<bean class="com.company.product.longNamingStandard.migration.extractor.FieldMapping">
<property name="elementName" value="entitlement.contributor"/>
<property name="mapping" value="DocContributors"/>
</bean>
</list>
</property>
The long class name(s) effect readability & also create a refactoring overhead.
Is it possible to alias the class name and use a short name to declare the beans? Or is there an alternate best practice I'm missing?
Probably a bit late for you, but hopefully useful for others:
You can use parent beans to accomplish this.
First declare a parent bean as a template:
<bean id="FieldMapping" class="com.company.product.longNamingStandard.migration.extractor.FieldMapping"/>
Then use it elsewhere, using the parent attribute.
<property name="mappingData">
<list>
<bean parent="FieldMapping">
<property name="elementName" value="entitlement.user"/>
<property name="mapping" value="DocUsers"/>
</bean>
<bean parent="FieldMapping">
<property name="elementName" value="entitlement.contributor"/>
<property name="mapping" value="DocContributors"/>
</bean>
</list>
</property>
Please note my convention here is to use upper case id's here for the parent template beans.
each <bean/> comes with an attribute of name and id to help you reference those beans later in your configuration.
I would suggest using the id for declaring the bean.
your config could look like:
<bean id="fooBean" class="com.example.foo"/>
<bean id="barBean" class="com.example.bar"/>
<list>
<ref>fooBean</ref>
<ref>barBean</ref>
</list>
You may try to represent your mapping in some short form, and then convert it to the list of FieldMappings. For example, mappings from your snippet may be represented as a map.
As a theoretic exercise in Spring 3 you can do this with Spring Expression Language (if FieldMapping has the apropriate constructor):
<util:map id = "m">
<entry name = "entitlement.user" value = "DocUsers" />
<entry name = "entitlement.contributor" value = "DocContributors" />
</util:map>
...
<property name = "mappingData"
value = "#{m.![new com.company.product.longNamingStandard.migration.extractor.FieldMapping(key, value)]}" />
If this expression is too obscure, you may implement a FactoryBean to take a short form of your mapping data (for example, a map, as in this example) and return a configured list of FieldMappings:
<property name = "mappingData">
<bean class = "FieldMappingListFactoryBean">
<property name = "mappings">
<map>
<entry name = "entitlement.user" value = "DocUsers" />
<entry name = "entitlement.contributor" value = "DocContributors" />
</map>
</property>
</bean>
</property>
However, if your field mappings are some kind of reusable DSL, you may try to think about implementing a namespace extension.
I found a way to simulate an effect similar to a "import com.Foo;" in java code. The best option I could find was to use a PropertyPlaceholderConfigurer with local properties defined. Using your example, here's the configuration that you would put at the top of your spring config file to define a "class_FieldMapping" property:
<bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<description>Define properties equivalent to "import foo;" in java source</description>
<property name="properties">
<props>
<prop key="class_FieldMapping">com.company.product.longNamingStandard.migration.extractor.FieldMapping</prop>
</props>
</property>
</bean>
Then, you can use that property within your beans:
<property name="mappingData">
<list>
<bean class="${class_FieldMapping}">
...
</bean>
<bean class="${class_FieldMapping}">
...
</bean>
</list>
</property>
This has the benefit that use can also use it for things where you actually need the class name, and can't reference an instance of an object:
<util:constant static-field="${class_FieldMapping}.MYSTATICVAR" />
Why not declare those inner beans as separate top-level beans with their own names, and then reference them in the list ?
If I use PropertyPlaceholderConfigurer it leads to several exceptions in debug log. It works, but it seems it doesn't work on the first try.