Loading String from file into Spring bean property - java

In my spring xml file I have a bean:
<bean id="config" class="com.example.BeanConfig">
<property name="description" value="Long Description Here" />
</bean>
Instead of defining the long string inline, I want to read the string from description.txt. Is there any way to do this in the xml without writing a Java class to handle it?
I already came across How do I load a resource and use its contents as a string in Spring but I am unclear how to get the bean contents into a property value.


You can use Spring's property placeholder and ${property_name} see https://dzone.com/articles/properties-spring

Related

What is the xml equivalent of this bean configuration where an object is being passed for which there is no bean configuration defined?

I need to add OAuth client to a Spring 3 project. I need to use xml based configuration. And I want to know the xml equivalent of the following bean configuration I found in another Spring project. Note that there is an input parameter in the bean definition where an object of type OAuth2ClientContext is being passed (OAuth2ClientContext is an Interface) and is named clientContext. But no bean definition is written anywhere for clientContext. What does this mean? And how would you write this in xml?
#Bean
public OAuth2RestTemplate oauth2RestTemplate(OAuth2ClientContext clientContext){
return new OAuth2RestTemplate(oauth2Resource(), clientContext);
}

The configuration should be like this
<bean id="client" class="package.OAuth2ClientContext" />
<bean id="resource" class="package.Oauth2Resource" />
<bean id="restTemplate" class="package.Oauth2Resource">
<property name="nameOfPropertyResource" ref="resource" />
<property name="nameOfPropertyClient" ref="client" />
</bean>
are you sure that the bean client is not declared? Maybe it’s declared in some jar? If yes you should find it’s name and use the name in the ref

Spring annotation to create a jexl2.Expression

I’m trying to understand a piece of Spring code that I need to adapt.
I have:
<bean id="…" class="…">
<property name="expr"
value="teams.contains(member.team) and not empty(member.projects)" />
</bean>
The corresponding class has a field
private Expression expr;
of type
org.apache.commons.jexl2.Expression
Now I am trying to find the appropriate Spring annotation to get rid of the XML file. But I cannot even understand how a simple String property can be injected as a jexl2.Expression object. How does this work?

A friend found the answer:
There was another XML file with this:
<bean id="bean_for_ExprConverter" class="package.of.custom.ExpressionConverter">
<constructor-arg ref="bean_for_JexlEngine"/>
</bean>
and also, in the project’s properties:
application.spring.converters = #{{\
#'bean_for_ExprConverter'\
}}
Thus, as long as the converter bean is defined, it should be enough to simply inject the expression string with the #Value annotation.

Java spring bean wont load xml config file

I want to use some values that are stored in a config file. Im trying to load in the config file and use it with a bean. Im new to spring and beans so im not really sure the best implementation for this. But i want to use the values as constructor arguments to the bean. I have a packet beans with the xml file beans in it. And in the same map "src/java/main" is the other packet with the xml file credentials.config.
/TwitterDownload/src/main/java/TwitterProjectNTS/beans/beans.xml qualified name for beans
/TwitterDownload/src/main/java/TwitterProjectNTS/TwitterDownload/credentials.config qualified name for credebtials.config
<import
resource="/TwitterDownload/src/main/java/TwitterProjectNTS/TwitterDownload/credentials.config" />
<bean id="TwitterConfigurationStartupSettings"
class="">
<constructor-arg
value=""></constructor-arg>
<constructor-arg
value=""></constructor-arg>
<constructor-arg
value=""></constructor-arg>
<constructor-arg
value=""></constructor-arg>
</bean>
I have read many articles about this but have not got a good understanding for how to really get this to work. Seems like there are many ways to read and use the values from the file.
Grateful for answears

Spring 3.2 properties issue with #Value

I've searched stackoverflow, read docs and can not seem to get my #Value("${myproperty.value}") to give me anything other than null.
I have some beans that I have defined in my spring-servlet.xml as well the properties file.
<!-- Load properties files -->
<context:property-placeholder location="classpath:MyProperties.properties" ignore-unresolvable="true" />
The properties file gets loaded without errors. In the same xml I have defined a bean.
<bean id="pushNotification" class="com.mydomian.actions.MyClass"/>
In the bean I have properties that use the #Value.
private #Value("${some.property}") String propertyValue;
My properties are always null.

You need to declare
<context:annotation-config />
to enable annotation processing.

Spring: Get inline bean by name

I would like to get inner bean by it's name. Is it possible with Spring API?
Right now I'm using such Spring 2.5 API
ConfigurableApplicationContext.getBean(String paramString)
Example of XML:
<bean id="parent" parent="t_Parent">
<property name="items">
<bean id="child" parent="t_Child">
<property name="ABC" value="test"/>
</bean>
</property>
</bean>
I would like to get inner (t_Child) bean by id "child". E.g. ConfigurableApplicationContext.getBean("child"). Spring can't find such bean (because it's inner). At the same time .getBean("parent") works fine.
Any thoughts?

You can't.
From the docs:
A element inside the or elements is used to define a so-called inner bean. An inner bean definition does not need to have any id or name defined, and it is best not to even specify any id or name value because the id or name value simply will be ignored by the container.
If you need it like that, define it as a regular bean.

You can't, but you can create you inner bean outside (so it's no longer an inner bean...) and then reference it inside the property:
<bean id="child" parent="t_Child">
<property name="ABC" value="test"/>
</bean>
<bean id="parent" parent="t_Parent">
<property name="items" ref="child"/>
</bean>

Apart from the other (mostly valid) answers and solutions, I guess the spring way would be to use the BeanWrapper interface:
final BeanWrapper bw =
new BeanWrapperImpl(applicationContext.getBean("parent"));
Object innerBean = bw.getPropertyValue("child");
But I guess that implies that there must be a getter for the property (not only a setter).
Reference:
BeanWrapper (javadoc, 2.5 version)
Bean manipulation and the BeanWrapper (reference, 2.5 version)

If you move up to Spring 3.x, you should be able to do this with the Spring Expression Language. There are examples of directly referencing a bean property from another property (like in link text). The code to do this from Java would be somewhat similar, although I can't find an exact example of this scenario.
However, I would say that if you're trying to use "getBean()", you're doing something wrong. You could just as easily use the SpEL in your context to define a bean or a bean property that references that inner bean.

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