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
Related
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.
I want to create a spring bean as below.
<bean id="qNameString" class="javax.xml.xpath.XPathConstants.STRING"/>
Here I want the reference to return type which is a QName but I understand the way I referred is wrong. Can someone please help on this.
That won't work, because class="javax.xml.xpath.XPathConstants.STRING" makes no sense, since what you're referring to isn't a class.
You can refer to static fields using <util:constant>, as documented here:
<property name="...">
<util:constant static-field="javax.xml.xpath.XPathConstants.STRING"/>
</property>
Spring can create a QName for you like this:
<bean id="qName" class="java.xml.namespace.QName">
<constructor index="0" value="localpart"/>
<constructor index="1" value="namespaceURI"/>
</bean>
Replace localpart and namespaceURI with the local name and namespace.
To reference a constant in a class, like javax.xml.xpath.XPathConstants.STRING
<bean id="qNameString" class="org.springframework.beans.factory.config.FieldRetrievingFactoryBean">
<property name="targetField" value="javax.xml.xpath.XPathConstants.STRING"/>
</bean>
A shorter version is available with the util schema:
<util:constant static-field="java.xml.xpath.XPathConstants.STRING"/>
Apart from being shorter, the id of the bean will be java.xml.xpath.XPathConstants.STRING rather than qNameString.
See FieldRetrievingFactoryBean and The util schema
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)
<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)
I just spent too much time of my day trying to figure out some errors when hooking up some JNDI factory bean. The problem turned out to be that instead of this...
<bean id="someId" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName" value="java:comp/env/jdbc/loc"/>
</bean>
I had actually written this...
<bean id="someId" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName" value="jdbc/loc"/>
</bean>
I infer that the java:comp/env/ perhaps references some environment variable and makes it so that, ultimately, my context file is looked at. The only difference is java:comp/env/. From an expert's mouth, what does that do?
Without the java:comp/env/ prefix in the value, I would get an error that said "Name jdbc is not bound in this Context".
Quoting https://web.archive.org/web/20140227201242/http://v1.dione.zcu.cz/java/docs/jndi-1.2/tutorial/beyond/misc/policy.html
At the root context of the namespace
is a binding with the name "comp",
which is bound to a subtree reserved
for component-related bindings. The
name "comp" is short for component.
There are no other bindings at the
root context. However, the root
context is reserved for the future
expansion of the policy, specifically
for naming resources that are tied not
to the component itself but to other
types of entities such as users or
departments. For example, future
policies might allow you to name users
and organizations/departments by using
names such as "java:user/alice" and
"java:org/engineering".
In the "comp" context, there are two
bindings: "env" and "UserTransaction".
The name "env" is bound to a subtree
that is reserved for the component's
environment-related bindings, as
defined by its deployment descriptor.
"env" is short for environment. The
J2EE recommends (but does not require)
the following structure for the "env"
namespace.
So the binding you did from spring or, for example, from a tomcat context descriptor go by default under java:comp/env/
For example, if your configuration is:
<bean id="someId" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName" value="foo"/>
</bean>
Then you can access it directly using:
Context ctx = new InitialContext();
DataSource ds = (DataSource)ctx.lookup("java:comp/env/foo");
or you could make an intermediate step so you don't have to specify "java:comp/env" for every resource you retrieve:
Context ctx = new InitialContext();
Context envCtx = (Context)ctx.lookup("java:comp/env");
DataSource ds = (DataSource)envCtx.lookup("foo");
There is also a property resourceRef of JndiObjectFactoryBean that is, when set to true, used to automatically prepend the string java:comp/env/ if it is not already present.
<bean id="someId" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName" value="jdbc/loc"/>
<property name="resourceRef" value="true"/>
</bean>
After several attempts and going deep in Tomcat's source code I found out that the simple property useNaming="false" did the trick!! Now Tomcat resolves names java:/liferay instead of java:comp/env/liferay