Develop Reference

How to use Spring's Resource Bundle in a custom library tag?

My Resource bundle is working fine with Controllers and Services etc, but somehow I can't access it within a custom tag.
<bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename" value="classpath:/spring/messages" />
<property name="defaultEncoding" value="UTF-8" />
</bean>
Here is a part of the tag:
#Component
public class FormSection extends BodyTagSupport {
private static final long serialVersionUID = 1L;
#Autowired
private ReloadableResourceBundleMessageSource messageSource;
#Override
public int doStartTag() throws JspException {
try {
// messageSource causes a NULL POINTER here
messageSource.getMessage("name", null, new Locale("us")));
return EVAL_BODY_INCLUDE;
}
I am getting a NullPointerException; Autowire doenst work. I can see my class is being scanned.
I also tried using applicationContext by implementing ApplicationContextAware but doenst work:
messageSource = (ReloadableResourceBundleMessageSource)applicationContext.getBean("messageSource");
Any help is welcome!

Spring injection tricks

I have: injecting MyClass and String objects into Utils at constructor.
Questions:
How does it works when in Utils bean definition (look at beans definition section) I mentioned only the second argument of Utils constructor?
How to pass MyClass mock into Utils object in unit tests? I mean how to redefine the bean definition?
Utils.java
public class Utils {
#Inject
public Utils(MyClass obj, String val) {
this.obj = obj;
this.val = val;
}
Beans definition:
<bean class="com.mypack.MyClass"/>
<bean id="utils" class="com.mypack.Utils">
<constructor-arg value="bucket" />
</bean>

You can define define another(test) context for the unit tests:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations = { "my-test-context.xml",
"some-other-context.xml" })
public class SkipSampleFunctionalTests {
#Autowired
private SomeBean bean;
...
}
If you want to override only one bean, you can import your main(core) context int the test context and change only the desired bean:
<import resource="main-context.xml"/>
<bean id="x" class="com.asd.MyClass">
<property name="y" ref="y"/>
</bean>

Spring Annotation : Converting XML Configuration to Annotation

I am using xml configuration in my Spring Application. Now i would like to convert the existing classes to use annotation(like #service, #Repository etc) instead of xml configuration.
Business Logic(Irrelevant for this question, just for understanding):
Sevice connnects to Americas database and find the skus(products) and deactivates the skus.
Sevice connnects to EMEA database and find the skus(products) and deactivates the skus.
Here is the sample code.
/* Service code, which has 2 instances of SkuDAO, one connecting to US database and one connecting to EMEA database */
public class DeactivationService {
private static final Logger LOG = Logger.getLogger(DeactivationService.class);
private SkuDAO amerdao; //Dependency Injection Amer
private SkuDAO emeadao; //Dependency Injection EMEA
public DeactivationService(SkuDAO amerdao,SkuDAO emeadao) {
this.amerdao=amerdao;
this.emeadao=emeadao;
}
/*
* Step 1: find inactive sku in americas skudao1.find()
* Step 2: find inactive sku in emea skudao2.find()
* Step 3: deactivate sku in americas
* Step 4: deactivate sku in emea
*/
public void deactivateSku() {
List<Sku> totalList = new ArrayList<Sku>();
List<Sku> amerList = amerdao.find();
List<Sku> emeaList = emeadao.find();
amerdao.deactivate(amerList);
emeaList.deactivate(emeaList);
}
}
/* DAO interface */
public interface SkuDAO {
public List<Sku> find();
public void deactivate(List<Sku>);
}
/* DAO Implementation
Here one constructor in which DataSource is injected
*/
public class SkuDAOImpl implements SkuDAO {
private DataSource datasource; //Dependency injection
private JdbcTemplate jdbcTemplate;
public SkuDAOImpl(DataSource datasource) {
this.datasource=datasource;
}
public List<Sku> find() {
//some processing to find the sku, purposely left empty as it is a sample code
}
public void deactivate(List<Sku>) {
//some processing to deactivate the sku, purposely left empty as it is a sample code
}
}
Spring Configuration:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:property-placeholder location="file:${dbconfiguration}"/>
<bean id="AmericasDataSource" class="dell.harmony.data.HarmonyBasicDataSource" destroy-method="close" >
<property name="url"><value>${HarmonyAmericasDb.url}</value></property>
<property name="driverClassName"><value>${HarmonyAmericasDb.driverClassName}</value></property>
<property name="username"><value>${HarmonyAmericasDb.username}</value></property>
<property name="password"><value>${HarmonyAmericasDb.password}</value></property>
<property name="initialSize"><value>${HarmonyAmericasDb.initialSize}</value></property>
<property name="maxActive"><value>${HarmonyAmericasDb.maxActive}</value></property>
<property name="maxWait"><value>${HarmonyAmericasDb.maxWait}</value></property>
<property name="maxIdle"><value>${HarmonyAmericasDb.maxIdle}</value></property>
<property name="minIdle"><value>${HarmonyAmericasDb.minIdle}</value></property>
<property name="removeAbandoned"><value>${HarmonyAmericasDb.removeAbandoned}</value></property>
<property name="removeAbandonedTimeout"><value>${HarmonyAmericasDb.removeAbandonedTimeout}</value></property>
</bean>
<bean id="EMEADataSource" class="dell.harmony.data.HarmonyBasicDataSource" destroy-method="close" >
<property name="url"><value>${HarmonyEMEADb.url}</value></property>
<property name="driverClassName"><value>${HarmonyEMEADb.driverClassName}</value></property>
<property name="username"><value>${HarmonyEMEADb.username}</value></property>
<property name="password"><value>${HarmonyEMEADb.password}</value></property>
<property name="initialSize"><value>${HarmonyEMEADb.initialSize}</value></property>
<property name="maxActive"><value>${HarmonyEMEADb.maxActive}</value></property>
<property name="maxWait"><value>${HarmonyEMEADb.maxWait}</value></property>
<property name="maxIdle"><value>${HarmonyEMEADb.maxIdle}</value></property>
<property name="minIdle"><value>${HarmonyEMEADb.minIdle}</value></property>
<property name="removeAbandoned"><value>${HarmonyEMEADb.removeAbandoned}</value></property>
<property name="removeAbandonedTimeout"><value>${HarmonyEMEADb.removeAbandonedTimeout}</value></property>
</bean>
**<!-- Sku Deactivation -->**
<bean id="SkuAmerDao" class="dell.harmony.service.skudeactivation.dao.SkuDAOImpl">
<constructor-arg index="0"><ref bean="AmericasDataSource"/></constructor-arg>
</bean>
<bean id="SkuEMEADao" class="dell.harmony.service.skudeactivation.dao.SkuDAOImpl">
<constructor-arg index="0"><ref bean="EMEADataSource"/></constructor-arg>
</bean>
<bean id="ServiceManager" class="dell.harmony.service.skudeactivation.service.DeactivationService">
<constructor-arg index="0"><ref bean="SkuAmerDao"/></constructor-arg>
<constructor-arg index="1"><ref bean="SkuEMEADao"/></constructor-arg>
</bean>
</beans>
Now i want to convert the above classes to highlighted inside xml("Sku Deactivation") , into annodation.
My code for convertion is as follows:
#Service
public class DeactivationService {
private static final Logger LOG = Logger.getLogger(DeactivationService.class);
private SkuDAO amerdao; //Dependency Injection Amer
private SkuDAO emeadao; //Dependency Injection EMEA
#Autowired(required=true)
public DeactivationService( #Qualifier("SkuAmerDao") SkuDAO amerdao, #Qualifier("SkuEMEADao") SkuDAO emeadao) {
this.amerdao=amerdao;
this.emeadao=emeadao;
}
}
In the above constructor, now 'amerdao' instance, should be injected with AmericasDataSource and 'emeadao' with EMEADataSource, how to do that?
Please note, i dont have a setter in the SkuDAOImpl. Also there is only one datasource instance inside the SkuDAOImpl.
can you given sample code of SkuDAOImpl with annodation.
Any suggestion, to improve the coding from service to dao , if it can be done in a better way. (Not required to answer this)
EDITED NOW: just to be clear with question 1, I would like to remove the below two lines in Spring xml and use annotation instead my DeactivationService. Is it possible?
<bean id="SkuAmerDao" class="dell.harmony.service.skudeactivation.dao.SkuDAOImpl">
<constructor-arg index="0"><ref bean="AmericasDataSource"/></constructor-arg>
</bean>
<bean id="SkuEMEADao" class="dell.harmony.service.skudeactivation.dao.SkuDAOImpl">
<constructor-arg index="0"><ref bean="EMEADataSource"/></constructor-arg>
</bean>

What about:
#Service
public class DeactivationService {
private static final Logger LOG = Logger.getLogger(DeactivationService.class);
#Autowired
#Qualifier("SkuAmerDao")
private SkuDAO amerdao; //Dependency Injection Amer
#Autowired
#Qualifier("SkuEMEADao")
private SkuDAO emeadao; //Dependency Injection EMEA
// no constructor needed.
}
public abstract class BaseDao implements SkuDAO {
private final JdbcTemplate jdbcTemplate;
protected BaseDao() {
this.jdbcTemplate = new JdbcTemplate(getDataSource());
}
protected abstract DataSource getDataSource();
public List<Sku> find() {
//some processing to find the sku, purposely left empty as it is a sample code
}
public void deactivate(List<Sku>) {
//some processing to deactivate the sku, purposely left empty as it is a sample code
}
}
#Repository("SkuAmerDao")
public class SkuAmerDAOImpl extends BaseDao {
#Autowired
#Qualifier("AmericasDataSource")
private DataSource datasource; //Dependency injection
#Override
protected DataSource getDatasource() {
return dataSource;
}
}
#Repository("SkuEMEADao")
public class SkuEMEADAOImpl extends BaseDao {
#Autowired
#Qualifier("EMEADataSource")
private DataSource datasource; //Dependency injection
#Override
protected DataSource getDatasource() {
return dataSource;
}
}
Always the same principle:
class is made a bean by an annotation #Service, #Component, #Repository (those annotations can take the name of the bean as value)
injection of dependency is made on fields with #Autowired and if there are more than one corresponding bean (in your case you have two DataSources), add a #Qualifier to specify which one.
Full documentation here.

Retrieving property/value as string from Spring bean

I have the following in my context.xml:
<bean id="myBean" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>file:${specific.dir}/file1.properties</value>
<value>file:${specific.dir}/file2.properties</value>
<value>file:${specific.dir}/file3.properties</value>
<value>file:${specific.dir}/file4.properties</value>
</list>
</property>
</bean>
I am retrieving this bean in a POJO through a static spring application context, and going through the debugger this does seem to work.
Is there anyway for me to retrieve the four values in the list, and the property name in this POJO?
my staticSpringApplicationContext is as follows :
public class StaticSpringApplicationContext implements ApplicationContextAware {
private static ApplicationContext CONTEXT;
public void setApplicationContext(ApplicationContext context) throws BeansException {
CONTEXT = context;
}
public static Object getBean(String beanName) {
return CONTEXT.getBean(beanName);
}
}
and following this in my POJO I have:
StaticSpringApplicationContext.getBean("myBean");
Any help or guidance is greatly appreciated. I have had more trouble with Spring than I care to admit.

You can use spring #Value annotation, smth like this:
#Component
public MyClass {
#Value("${some.prop.name1}")
private String myProp1;
}
file1.properties:
some.prop.name1=value1
I hope it will be helpful. Good luck.

Whether you can do this will depend on the bean definition. It must have a setLocations() method (or be correctly annotated) via which Spring will inject the values.
You would retrieve the values using a getter method on the bean if one exists. If not you will need to modify the bean.

Spring 3 validation not working

I have a user entity in my application which I need to validate.
public class User {
private String userName;
private String password;
public void setUserName(String userName){
this.userName = userName;
}
public getUserName(){
return this.userName;
}
// and so on
}
For this I have created a UsersValidator like below.
public class UserValidator implements Validator {
public boolean supports(Class clazz) {
return User.class.equals(clazz);
}
public void validate(Object obj, Errors errors) {
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "userName", "field.required");
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "password", "field.required");
}
}
and I have a controller like this
#RequestMapping(value = "/login", method = RequestMethod.POST)
public String home(#Valid User user,
BindingResult result) {
if (result.hasErrors()) {
return "loginForm";
} else {
//continue
}
}
The binding result does not have any errors.
What else I need to do in order for the validation to work? Do I have make any changes in the controller or the spring configuration file.
<mvc:annotation-driven />
<context:component-scan base-package="com.myapp" />
<mvc:resources location="/resources/" mapping="/resources/**" />
<bean id="viewResolver"
class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass">
<value>org.springframework.web.servlet.view.tiles2.TilesView</value>
</property>
</bean>
<bean id="tilesConfigurer"
class="org.springframework.web.servlet.view.tiles2.TilesConfigurer">
<property name="definitions">
<list>
<value>/WEB-INF/tiles.xml</value>
</list>
</property>
</bean>
<bean id="messageSource"
class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basenames">
<list>
<value>com/dimex/resourceBundles/ApplicationResources</value>
<value>com/dimex/resourceBundles/errors</value>
</list>
</property>
</bean>
<mvc:interceptors>
<bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor">
<property name="paramName" value="locale"></property>
</bean>
</mvc:interceptors>
<bean id="localeResolver"
class="org.springframework.web.servlet.i18n.SessionLocaleResolver">
<property name="defaultLocale" value="en" />
</bean>
EDIT:-
Do I need to have hibernate validator in my classpath. We are not using hibernate in our application.
Please help.
EDIT2:-
When I use validation annotations (#NotNull, #Size etc) directly in my entity class then #Valid annotations in controller works but if I remove them from my entities and try to use the validator written above then #Valid does not work.
Is it like that #Valid annotations only work with the validation annotation in the entities only and not with the validators? In order to use my validators will I have to invoke the validate method in my validator directly?

From what I understand you are trying to combine JSR-303 #Valid annotation with classic spring validation. Why would you want to do this? The equivalent JSR-303 annotations for UserValidator class would be something like below:
#NotNull
#Size(min=1)
private String userName;
#NotNull
#Size(min=1)
private String password
...
The spring documentation illustrates the steps needed to configure JSR-303 validation. You would need hibernate-validator (or another JSR-303 provider) for the above to work. You would also need to configure the validator bean as below.
<bean id="validator"
class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean"/>
The other answers to this question are in the same line as well.

You need to define the validator to use in your controller using the #InitBinder annotation, for example:
#InitBinder
protected void initBinder(WebDataBinder binder) {
binder.setValidator(new UserValidator());
}

Other way around is to call spring validator initialization from your controller
DataBinder dataBinder = new DataBinder(user);
dataBinder.setValidator(userValidator);
dataBinder.validate();
BindingResult result = dataBinder.getBindingResult();
if(result.hasErrors() == false) {
// error exists
}

You need to put #Component on the Validator implementation so that Spring container can recognize it as:
#Component
public class UserValidator implements Validator {
and use following method in the controller:
#InitBinder(UserVO)
protected void initBinder(WebDataBinder binder) { binder.setValidator(userValidator);
}

If you use JSR-303-style validation with Spring (i.e. a global Validator instance provided by a JSR-303 implementation, such as Hibernate Validator), and you have an #InitBinder-annotated method in your Controller, you must inject the Validator into your Controller and set it in the #InitBinder method:
#Autowired
public void setValidator(Validator validator) {
this.validator = validator;
}
#InitBinder
protected void initBinder(WebDataBinder binder) {
binder.setValidator(this.validator);
}
The WebDataBinder's validator is by default set to null, not (as you would expect) to the global JSR-303 Validator instance, so your models won't be validated by Spring unless you set the Validator instance manually here.
This is only if you have an #InitBinder method. If you don't, everything works as expected.