I have the following configuration in my applicationContext.xml:
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:app.properties</value>
</list>
</property>
</bean>
Now, in my java class, how can I read the values from the file app.properties?
With Spring 3.0 you can use the #Value annotation.
#Component
class MyComponent {
#Value("${valueKey}")
private String valueFromPropertyFile;
}
Actually PropertyPlaceholderConfigurer is useful to inject values to spring context using properties.
Example XML context definition:
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName"><value>${driver}</value></property>
<property name="url"><value>jdbc:${dbname}</value></property>
</bean>`
Example properties file:
driver=com.mysql.jdbc.Driver
dbname=mysql:mydb
Or you can create bean like
<bean name="myBean" value="${some.property.key}" />
and then inject this bean into your class
Related
I am trying to use consul for centralised configuration for spring application. When I use annotation based configuration like Example 1 it works perfectly.
//Example 1
#Configuration
#EnableConsulPropertySource({"root/api/defaults", "root/global/defaults"})
public class ApplicationConfiguration {
#Value("httpclient.pool.maxtotal")
private int maxTotal;
#Value("httpclient.pool.defaultmaxperroute")
private int maxPerRoute;
...
}
However I could not find a way to use consul properties directly in xml.
<bean id="properties" class="org.springframework.SomeBeanToEnableConsulInXMLConfig">
<property name="locations">
<list>
<value>root/api/defaults</value>
<value>root/global/defaults</value>
</list>
</property>
</bean>
...
<bean name="http.client" class="com.xxx.HTTPClient">
<property name="maxTotal" value="${httpclient.pool.maxtotal}" />
<property name="defaultMaxPerRoute" value="${httpclient.pool.defaultmaxperroute}" />
</bean>
Does spring has something like SomeBeanToEnableConsulInXMLConfig or any hints on implementing this class?
Here i tried 2 write cod 2 get list from Mysql Database using spring nd Hibernate.
But problem is here that how initialize **org.hibernate.Session se through "applicationContext.xml" file by bean class....
public void getList(**Session se**){
String liststudent="from StudentList stud";
Query q=se.createQuery(liststudent);
List<Object> list=q.list();
for(Object obj:list){
Object studarr[]=(Object[])obj;
System.out.println("Data at Zero Index"+studarr[0]);
}
}
As here property name **template** has been initialized by the ref template.
Is there any way to initialize Session se.
<bean name="mydao" class="dao.MyDao">
<property name="template" ref="template"></property>
</bean>
using your context.xml file
define sessionFactory
<bean id="sessionFactory" class="LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<!--define other properties...mapping files
</bean>
define hibernateTemplate
<bean id="template" class="*HibernateTemplate">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
then
<bean name="mydao" class="dao.MyDao">
<property name="template" ref="template"></property>
</bean>
NOTE: the class package has been ommitted
How do I make use of #Value in the following 2 cases?
case 1: I have a PropertyPlaceholderConfigurer bean defined as follows
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<value>file:#{ systemProperties['user.home']}/myconf/settings.properties</value>
</property>
</bean>
Case 2: I did not define the bean, but i have declared property-place holder in the context as follows
<context:property-placeholder
location="file:#{ systemProperties['user.home']}/myconf/settings.properties" />
In both cases you would use like
#Value(value="${key.in.file}")
private String myVar;
I want to get specific value based on request from the property file.how to do that?
I have following spring configuration.i want to set the value for Exprops as per the request and get corresponding values from the properties file
<bean id="Prop" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location">
<value>classpath:ErrorMessage.properties</value>
</property>
</bean>
<bean id="PropertiesBean" class="com.util.PropertiesUtil">
<property name="Exprops" value="${EXampleExceptiion}"></property>
</bean>
Use the PropertiesFactoryBean to inject the Properties in a Bean.
<bean id="myPropertiesBean"
class="org.springframework.beans.factory.config.PropertiesFactoryBean">
<property name="location" value="classpath:ErrorMessage.properties"/>
</bean>
This provides a Properties Object/Bean which can be injected under the name myPropertiesBean in any Bean (<property name="x" ref="myPropertiesBean"/>).
In addition Spring provides the util namespace (since Spring 2.5):
There you can write the PropertyFactoryBean definition a bit shorter:
<util:properties id="myPropertiesBean"
location="classpath:ErrorMessage.properties"/>
#see Spring Reference Chapter C.2.2.3.
All use the following for doing this programmatically
XmlBeanFactory factory = new XmlBeanFactory(new FileSystemResource("beans.xml"));
PropertyPlaceholderConfigurer cfg = new PropertyPlaceholderConfigurer();
cfg.setLocation(new FileSystemResource("jdbc.properties"));
cfg.postProcessBeanFactory(factory);
<util:properties id="" location="location of prop file" />
this return java.util.Properties object
I want to do something like the following in spring:
<beans>
...
<bean id="bean1" ... />
<bean id="bean2">
<property name="propName" value="bean1.foo" />
...
I would think that this would access the getFoo() method of bean1 and call the setPropName() method of bean2, but this doesn't seem to work.
What I understood:
You have a bean (bean1) with a
property called "foo"
You have another bean (bean2) with a
property named "propName", wich also
has to have the same "foo" that in
bean1.
why not doing this:
<beans>
...
<bean id="foo" class="foopackage.foo"/>
<bean id="bean1" class="foopackage.bean1">
<property name="foo" ref="foo"/>
</bean>
<bean id="bean2" class="foopackage.bean2">
<property name="propName" ref="foo"/>
</bean>
....
</beans>
Doing this, your bean2 is not coupled to bean1 like in your example. You can change bean1 and bean2 without affecting each other.
If you REALLY need to do the injection you proposed, you can use:
<util:property-path id="propName" path="bean1.foo"/>
You need to use PropertyPathFactoryBean:
<bean id="bean2" depends-on="bean1">
<property name="propName">
<bean class="org.springframework.beans.factory.config.PropertyPathFactoryBean">
<property name="targetBeanName" value="bean1"/>
<property name="propertyPath" value="foo"/>
</bean>
</property>
</bean>
I think you have to inject bean1, then get foo manually because of a timing issue. When does the framework resolve the value of the target bean?
You could create a pointer bean and configure that.
class SpringRef {
private String targetProperty;
private Object targetBean;
//getters/setters
public Object getValue() {
//resolve the value of the targetProperty on targetBean.
}
}
Common-BeanUtils should be helpful.