Get message in Java code ( Spring 3 ) - spring

<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"
p:basename="messages" />
bean and obviously in my velocity files I can use #springMessage() to get needed message. But what if I want to get that message in my *.java controller? Is there some annotation that I can use like ?
#Annotation('message')
private String message;
Or I need to do it in different way?
Thanks

As long as you don't need any internationalization, then you can use the messages.properties file with a PropertyPlaceHolderConfigurer (see the docs), along with the #Value annotation
In XML:
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations" value="classpath:messages.properties"/>
</bean>
And in Java:
#Value('message')
private String message;
You'll also need <context:annotation-config/> to make this work (see docs)

Related

How to define a PropertyPlaceholderConfigurer local to a specific bean?

I've been using org.springframework.beans.factory.config.PropertyPlaceholderConfigurer and in my experience ("citation needed" LOL) it sets the property values globally.
Is there a way to specify different PropertyPlaceholderConfigurer instances for different beans within the same application context xml?
My current code is similar to
<bean id="a" class="X">
<property name="foo" value="bar"/>
<property name="many" value="more"/>
</bean>
<bean id="b" class="X">
<property name="foo" value="baz"/>
<property name="number_of_properties" value="a zillion"/>
</bean>
I would like to do something like (pseudo-code below):
<bean id="a" class="X">
... parse the contents of "a.properties" here ...
</bean>
<bean id="b" class="X">
... parse the contents of "b.properties" here ...
</bean>
The above is non-working pseudo code to illustrate the concept; the point being, I want a different properties file to feed each bean.
WHY?
I want to have those specific properties in separate properties file and not in XML.
I think the following link can br helpful to you.
Reference Link
where #Value("${my.property.name}") annotation is used to bind the property file to a variable of type Properties which will reside in your bean class where you intend to use that properties file.
and you can define multiplte proprtiesplaceholder as below:
<bean id="myProperties"
class="org.springframework.beans.factory.config.PropertiesFactoryBean">
<property name="locations">
<list>
<value>classpath*:my.properties</value>
</list>
</property>
</bean>
and use the id as reference in your bean variable to initialize properties file to the bean.
And it will be handy to include with placeholder bean.
Kindly refer Importance of Unresolvable Placeholder link for detailed info regarding its usage.
Hope this was helpful.

How to use placeholder in Spring config without any properties files?

I want to have just a single property and I don't want to create a separate properties file for that. I want to inject it in a bean using the #Value annotation like this:
#Value("#{my.placeholder}") private String lol;
as well use in other bean configuration like:
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="maxUploadSize" value="${my.placeholder}"/>
</bean>
How can I achieve that without using property files?
You can use #Value("someValue") private String lol;
In this case you won't need any properties file.

Create a Guava TypeToken in Spring xml config?

I'd like to be able to inject Guava TypeToken objects by specifying them as a bean in a Spring xml configuration. Is there a good way to do this? Has anyone written any cade/library to make this easier?
TypeToken seems to work by using reflection to introspect its generic types and is thus constructed using an anonymous class like:
new TypeToken<List<String>>() {}
Spring's xml config syntax doesn't seem to accept generics at all, presumably because it's built at runtime and doesn't "need" them (since generics are compile time checks and technically erased at runtime).
So the only way I know to instantiate a TypeToken bean is to do it in java:
TokenConfig.java:
#Configuration
public class TokenConfig {
#Bean
public TypeToken<List<String>> listOfStringsToken() {
return new TypeToken<List<String>>() {};
}
}
system-test-config.xml:
<beans>
<context:annotation-config/>
<bean class="com.acme.TokenConfig"/>
<bean class="com.acme.Consumer">
<property name="typeToken" ref="listOfStringsToken"/>
</bean>
</beans>
Is there a way to do this with just an xml config?
Maybe you can use spring FactoryBeans: look for factory methods at http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/beans.html
To answer my own question:
It IS possible to create a non-generic TypeToken using the static constructor TypeToken.of(Class), but this wont work for deeper generic types.
Here's the Spring xml config:
<bean class="com.google.common.reflect.TypeToken" factory-method="of">
<constructor-arg type="java.lang.Class" value="java.lang.Integer" />
</bean>
Which is equivelent to:
TypeToken.of(Integer.class)
and
new TypeToken<Integer>() {}
I also found a way to use the TypeToken.of(Type) constructor with a ParameterizedType constructed using Google Guice's Types utility. Guava has one too, but it's not public. :'(
I'm not sure if this is quite as robust as using TypeToken/TypeCapture, but it seems to work. Unfortunately it's pretty ugly and long... (maybe someone can simplify it?)
<bean class="com.google.common.reflect.TypeToken" factory-method="of">
<constructor-arg index="0">
<bean class="com.google.inject.util.Types" factory-method="newParameterizedType">
<constructor-arg index="0">
<value type="java.lang.Class">java.util.List</value>
</constructor-arg>
<constructor-arg index="1">
<array><value type="java.lang.Class">java.lang.String</value></array>
</constructor-arg>
</bean>
</constructor-arg>
</bean>
Which is equivelent to:
new TypeToken<List<String>() {}

Spring Configuration Query

I have one spring configuration file with entry like below...
<bean id="beanId" class="a.b.c.d.MyBean">
<property name="firstProperty" value="report_{date}.xls"/>
</bean>
Somewhere in my java code, I am fetching this bean and then its property "firstProperty" later.
I am little curious, when I get the value of property "firstProperty" I get report_.xls i.e report_20130307.xls
I have searched all my code including bundles, xmls but not clear that where we are setting {date} with todays timestamp.
Do you have any clue where we can do this?
Thanks
Jai
It is the property-placeholder mechanism.
Read more on http://static.springsource.org/spring/docs/3.2.x/spring-framework-reference/html/xsd-config.html#xsd-config-body-schemas-context-pphc.
In most of the cases, the values to property are set from properties file using expression language. Like
<bean id="dataSource" class="a.b.c.d.DataSource">
<property name="databaseUrl" value="{db.url}"/>
</bean>
Or if the property is a ref to another bean, e.g. Object B is member variable of Object A.
<bean id="refA" class="a.b.c.d.A">
<property name="b" ref="refB"/>
</bean>
<bean id="refB" class="a.b.c.d.B">
</bean>
Its quite simple guys...as we know setter are called for each property. So same in my case,
In bean we are setting variable "firstProperty" + today timestamp like below.
public void setfirstProperty(String firstProperty) {
this.firstProperty = firstProperty + <methodToReplaceDateStringWithTimeStamp>;
}
Thanks
Jai

How to do spring request parameter conversion

In a Spring 3 based web (portlet) application I have a controller with a method like this:
#RenderMapping
public ModelAndView handleRenderRequest(...,#RequestParam MyClass myObject)
{
...
}
Now I wonder: How do I tell spring how to convert the request parameter to MyClass. I found information about property editors and about the Converter interface and there seem to be some implications that Converter is the successor of the property editor, but nobody seems to like being explicit about it.
I implemented the converter interface for String to MyClass conversion. But how do I tell Spring about it? I am using annotation based configuration wherever possible, so I checked whether spring will detect the Converter from my classpath automatically, but it does not.
So thought that the part Configuring a ConversionService from the manual wants to tell me that I've got to add the following to my applicationContext.xml which I did:
<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
<property name="converters">
<list>
<bean class="some.package.MyConverter"/>
</list>
</property>
</bean>
Bit still:
org.springframework.beans.ConversionNotSupportedException: Failed to
convert value [...]
So what am I missing? And is there a way, to just configure a package and let spring scan this package for converters and register them automatically? And say that in one certain method I want to use a different converter than in all other methods. For example I want an integer that has a Luhn-Checksum to be checked and the checksum removed, how can I do that? Something like #RequestParam(converter=some.package.MyConverter.class) would be great.
EDIT
Ok, I just caught in the documentation:
Use the Formatter SPI when you're working in a client environment,
such as a web application, and need to parse and print localized field
values
So I guess that means I should use the Formatter SPI, yet a third possibility next to property editors and converters (I think I could really to with a comparison table or the like). I did implement the Parser interface as well and tried to register my converter using:
<bean id="conversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
<property name="converters">
<set>
<bean class="some.package.SortOrderEnumConverterSpring"/>
</set>
</property>
</bean>
As you can see I used "set" instead of "list" for specifying the converters. I set a debugging breakpoint in the FormattingConversionServiceFactoryBean.setConverters method which did not fire upon using list, but it did fire on using set.
Additionally I added
<mvc:annotation-driven conversion-service="conversionService"/>
And the namespace for the mvc-prefix to my applicationContext. But still I get the conversion not supported exception.
I also tried going back to the converter approach and changed in my applicationContext.xml file the parameter list for converters from list to set, but that did not change anything either.
EDIT2
As digitaljoel pointed out it is possible to set different converters per controller using an initBinder method. I applied this to my controller:
#Autowired
private ConversionService conversionService;
#InitBinder
public void initBinder(WebDataBinder binder)
{
binder.setConversionService(conversionService);
}
And in my applicationContext.xml:
<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
<property name="converters">
<set>
<bean class="some.package.with.MyConverter"/>
</set>
</property>
</bean>
And all suddenly the conversion works just fine :-). But I am not quite happy about having to apply this to each and every of my controllers. There must be a way to just set it in my applicationContext for everyone, is there not? Good to know that I can override default if I need to (after all I asked for that), but I still want to set defaults.
And what about the Formatter stuff. Shouldn't I be using that instead of Converter?
Spring Portlet MVC 3.0 does not support
<mvc:annotation-driven conversion-service="conversionService"/>
Visit https://jira.springsource.org/browse/SPR-6817 for more info about this.
However you can add this to your common applicationContext
<bean
class="org.springframework.web.portlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="webBindingInitializer">
<bean
class="org.springframework.web.bind.support.ConfigurableWebBindingInitializer">
<property name="conversionService">
<list>
<ref bean="conversionService" />
</list>
</property>
</bean>
</property>
</bean>
This way you do not need add #InitBinder to every single controller
and of course
<bean id="conversionService"
class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
<property name="converters">
<list>
<!-- converter implementations here -->
</list>
</property>
</bean>
You are correct that Converter (and ConverterFactory) are the successors to property editors. Your problem may be that you are not accepting the appropriate type as a parameter to your converter, but that's hard to say without seeing the converter code. If you are expecting Long or Integer you may actually be getting a String from Spring and need to perform that key conversion yourself first.
As for configuration, I believe you need to list all of your converters in the bean configuration in your xml. If you annotate your converter implementation with #Component you might be able to reference it by the bean name instead of the fully qualified path, but I have only tried that for a ConverterFactory, not a Converter.
Finally, on specific converters, it looks like you may be able to configure the conversion service at the controller level (see Javi's answer on Setting up a mixed configuration for annotation-based Spring MVC controllers ) and then you could just place that method (and others that require that controller) into a controller that uses a secondary conversion service which you ought to be able to inject by name with the #Resource annotation.
Implement a WebArgumentResolver:
public class MyArgumentResolver implements WebArgumentResolver
{
#Override
public Object resolveArgument(MethodParameter methodParameter,
NativeWebRequest webRequest) throws Exception
{
Class<?> paramType = methodParameter.getParameterType();
if (paramType == MyClass.class)
{
String parameterName = methodParameter.getParameterName();
String stringParameter = webRequest.getParameter(parameterName);
return convert(stringParameter);
}
return UNRESOLVED;
}
}
And register it in your applicationContext.xml:
<bean class="org.springframework.web.portlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="customArgumentResolver">
<bean class="com.dshs.eakte.util.MyArgumentResolver" />
</property>
</bean>
This works and even has the advantage of allowing parameter conversion that is based on multiple method parameters.
To achieve something similar to what you're doing, I found this blog entry useful.
i think you need to use something like
public ModelAndView handleRenderRequest(...,#ModelAttribute("myObject") MyClass myObject)

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