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.
Related
I have a Junit which somewhere down the line invokes a DaoImpl and this DaoImpl has a datasource attribute. Since this DaoImpl extends NamedParameterJdbcDaoSupport where setDataSource is marked final I cannot autowire a setter for this. My code (only when) invoked from a Junit fails with NPE at dataSource.getConnection() due to the dataSource attribute being null.
Here are the two things that I tried that works,
1> if I try below snippet and use this second attribute dataSource2.getConnection() in the called method it works just fine.
#Autowired
private DataSource dataSource;
#Autowired
private DataSource dataSource2;
#Autowired
public void setDataSource2(DataSource dataSource2){
this.dataSource2=dataSource2;
}
2> If I call parent getter directly while obtaining a connection within the called method it works just fine.
getDataSource.getConnection()
But it always fails if I use dataSource.getConnection() for below variations that I have tried,
#Autowired
private DataSource dataSource;
#Autowired
public void setDs(DataSource dataSource) {
this.dataSource = dataSource
}
OR
#Autowired
private DataSource dataSource;
#Autowired
private DataSource dataSource2;
#Autowired
public void setDataSource2(DataSource dataSource) {
this.dataSource2 = dataSource;
this.dataSource = dataSource;
}
I have also tried suggestion provided here,
#Autowired
private DataSource dataSource;
#PostConstruct
private void initialize() {
setDataSource(dataSource);
}
and here
#Autowired
public void setDs(DataSource dataSource) {
setDataSource(dataSource);
}
I can just go use getDataSource().getConnection() but this line dataSource.getConnection() is used in many places within the application and I cannot change it everywhere, that piece of code works just fine when deployed on JBOSS application server, just not via my Junit. Much appreciated if anyone point me what is going on here for the solutions that I tried and what I could do interms of Junit to fix this without having to change functional part of the code?
My junit class and application context looks as below:
public class MyTestC extends TestCase {
private ApplicationContext context;
public void setContext(ApplicationContext context) {
this.context = context;
}
private AToolController aToolController;
public void setUp() throws NamingException {
context = new ClassPathXmlApplicationContext("classpath:MyTestC.xml");
aToolController = (AToolController) context.getBean("AToolController");
}
#Test
public final void testDoSomething() throws AppException {
//aToolController.invokeSomething();
}
}
Context xml:
<bean id="jdbcTemplate"
class="org.springframework.jdbc.core.JdbcTemplate"
scope="prototype">
<constructor-arg><ref bean="datasource"/></constructor-arg>
</bean>
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location">
<value>classpath:mytest.properties</value>
</property>
</bean>
<bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${mytest.jdbc.driverClassName}"></property>
<property name="url" value="${mytest.jdbc.url}"></property>
<property name="username" value="${mytest.jdbc.userName}"></property>
<property name="password" value="${mytest.jdbc.password}"></property>
</bean>
<bean id="ptDAO" class="com.ctl.abc.def.ghi.dao.AToolDAOImpl">
<property name="dataSource" ref="datasource"></property>
</bean>
<bean id="ptService" class="com.ctl.abc.def.ghi.service.AToolService">
<property name="ptDAO" ref="ptDAO"></property>
</bean>
<bean id="AToolController" class="com.ctl.abc.def.ghi.AToolController">
<property name="ptService" ref="ptService"></property>
</bean>
Use annotation in dao
#Repository("testDao")
public class TestDaoImpl extends JdbcDaoSupport implements BaseDao{
#Override
public Object addObject(String sqlid, Object obj) {
// TODO Auto-generated method stub
return null;
}
Caused by: java.lang.IllegalArgumentException: 'dataSource' or 'jdbcTemplate' is required
I do not want to use ：
<bean id="termsDao" class="com.manage.base.dao.impl.TestDaoImpl">
<property name="jdbcTemplate" ref="jdbcTemplate"/>
</bean>
this code set in xml， and “jdbcTemplate” has been defined in other “spring-xml”。
How to solve this problem by an annotation ：“'dataSource' or 'jdbcTemplate' is required”
You can use one of the below approaches. The first one - taking a dataSource is preferred / recommended as you don't expose a SpringFramework class in your public interface. Both will work.
#Repository("testDao")
public class TestDaoImpl extends JdbcDaoSupport implements BaseDao{
#Autowired
TestDaoImpl(DataSource dataSource) {
setDataSource(dataSource);
}
}
Or
#Repository("testDao")
public class TestDaoImpl extends JdbcDaoSupport implements BaseDao{
#Autowired
TestDaoImpl(JDBCTemplate template) {
setJdbcTemplate(template);
}
}
I even feel injecting datasource as a constructor to your DAO is a unnecessary coding step.
Why not inject datasource in Spring config XML into JDBC template and just get jdbctTemplate
object in every DAO.
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource"/>
</bean>
and let your DAO extend JDBCSupport class.
public class PersonDao extends JdbcDaoSupport{
public List<Person> selectAll(){
String selectAllSql = "SELECT * FROM PERSON;";
return getJdbcTemplate().query(selectAllSql, new PersonRowMapper());
........
}
}
Full example :
http://www.studytrails.com/frameworks/spring/spring-jdbc-dao-support.jsp
As per Spring documentation,
the steps to use Spring JdbcTemplate is as follows:
<?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-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<!-- Scans within the base package of the application for #Components to configure as beans -->
<context:component-scan base-package="org.springframework.docs.test" />
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${jdbc.driverClassName}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<context:property-placeholder location="jdbc.properties"/>
</beans>
And then,
#Repository
public class JdbcCorporateEventDao implements CorporateEventDao {
private JdbcTemplate jdbcTemplate;
#Autowired
public void setDataSource(DataSource dataSource) {
this.jdbcTemplate = new JdbcTemplate(dataSource);
}
// JDBC-backed implementations of the methods on the CorporateEventDao follow...
}
Basically, the JdbcTemplate is created inside the Component class using the setter for datasource.
Is there anything wrong with doing it this way instead so that there is exactly ONE instance of jdbcTemplate in the application?
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"
p:dataSource-ref="dataSource"
/>
And then injecting the jdbcTemplate itself directly into the Component
#Repository
public class JdbcCorporateEventDao implements CorporateEventDao {
#Resource("jdbcTemplate")
private JdbcTemplate jdbcTemplate;
// JDBC-backed implementations of the methods on the CorporateEventDao follow...
}
Is there a reason why the jdbcTemplate itself must not be injected into the component class directly?
SGB
You can do what you want. The javadoc of JdbcTemplate even clearly says it:
Can be used within a service implementation via direct instantiation with a DataSource reference, or get prepared in an application context and given to services as bean reference.
In the spring-context.xml add the following and
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource"/>
</bean>
and directly you can use jdbcTemplate by autowiring like
#Autowired JdbcTemplate jdbcTemplate;
example:
this.jdbcTemplate.query("select * from ******",new RowMapper());
You can also do it like
#Configuration
#Import({PersistenceConfig.class})
#ComponentScan(basePackageClasses = {
ServiceMarker.class,
RepositoryMarker.class }
)
public class AppConfig {
/**
* To resolve ${} in #Values, you must register a static PropertySourcesPlaceholderConfigurer in either XML or
* annotation configuration file.
*/
#Bean
public static PropertySourcesPlaceholderConfigurer propertyConfigInDev() {
return new PropertySourcesPlaceholderConfigurer();
}
}
PersistenceConfig
#Configuration
#PropertySource(value = { "classpath:database/jdbc.properties" })
#EnableTransactionManagement
public class PersistenceConfig {
#Autowired
private Environment env;
/**
* The #Bean annotation is used to declare a Spring bean and the DI requirements. The #Bean annotation is equivalent to
* the <bean> tag, the method name is equivalent to the id attribute within the <bean> tag.
*
* <bean id="mySqlDataSource" class="org.apache.commons.dbcp2.BasicDataSource" destroy-method="close"
p:driverClassName="${jdbc.mysql.driverClassName}"
p:url="${jdbc.mysql.url}"
p:username="${jdbc.mysql.username}"
p:password="${jdbc.mysql.password}" />
*
* #return
*/
#Bean(destroyMethod = "close")
public DataSource mySqlDataSource() {
BasicDataSource dataSource = new BasicDataSource();
dataSource.setDriverClassName(env.getProperty("jdbc.mysql.driverClassName"));
dataSource.setUrl(env.getProperty("jdbc.mysql.url"));
dataSource.setUsername(env.getProperty("jdbc.mysql.username"));
dataSource.setPassword(env.getProperty("jdbc.mysql.password"));
return dataSource;
}
#Bean(destroyMethod = "close")
public DataSource ls360DataSource() {
BasicDataSource dataSource = new BasicDataSource();
dataSource.setDriverClassName(env.getProperty("jdbc.ls360.driverClassName"));
dataSource.setUrl(env.getProperty("jdbc.ls360.url"));
dataSource.setUsername(env.getProperty("jdbc.ls360.username"));
dataSource.setPassword(env.getProperty("jdbc.ls360.password"));
return dataSource;
}
}
MySqlDaoImpl
#Repository
public class MySqlDaoImpl implements MySqlDao{
private static final Logger logger = LogManager.getLogger();
#Inject
private DataSource mySqlDataSource;
private JdbcTemplate mySqlJdbcTemplate;
#PostConstruct
public void afterPropertiesSet() throws Exception {
if (mySqlDataSource == null) {
throw new BeanCreationException("Must set mySqlDataSource on " + this.getClass().getName());
}
this.mySqlJdbcTemplate = new JdbcTemplate(mySqlDataSource);
}
#Override
public void callStoredProcedure(String storedProcedureName, Map<String, Object> inParamMap) throws Exception {
SimpleJdbcCall simpleJdbcCall = new SimpleJdbcCall(mySqlJdbcTemplate).withProcedureName(storedProcedureName);
SqlParameterSource in = new MapSqlParameterSource(inParamMap);
logger.info("Calling stored Procedure: " + storedProcedureName);
Map<String, Object> simpleJdbcCallResult = simpleJdbcCall.execute(in);
logger.info("Stored Procedure Result: " + simpleJdbcCallResult);
}
}
Main
public static void main(String[] args ) {
try (GenericApplicationContext springContext = new AnnotationConfigApplicationContext(AppConfig.class)) {
MySQLDao mySqlDao = springContext.getBean(MySQLDaoImpl.class);
try {
Map<String, Object> inParamMap = new HashMap<String, Object>();
inParamMap.put("iCourseId", 1);
mySqlCourseRenewalDao.callStoredProcedure("usp_processCourseRenewal", inParamMap);
} catch (Exception e) {
logger.error("Exception occurs", e);
}
} catch (Exception e) {
logger.error("Exception occurs in loading Spring context: ", e);
}
}
Thanks
There's nothing technically wrong with injecting and sharing JdbcTemplate in place of the underlying DataSource.
However, there are some design drawbacks to sharing JdbcTemplate, which may favor injecting DataSource instead:
Use of JdbcTemplate is an implementation detail of the DAO, and we like to keep those details hidden
JdbcTemplate is lightweight, so sharing it for efficiency is likely a premature optimization
Sharing a JdbcTemplate isn't risk-free as it has some mutable state (in addition to mutable state in the underlying DataSource)
That's assuming the the typical case where JdbcTemplate is used with its default configuration (fetchSize, maxRows, etc). If configuration is required, that may drive the design in a particular direction, e.g. a shared pre-configured JdbcTemplate injected from context, or even multiple JdbcTemplate instances owned by a single DAO.
I am using Spring3.1 on standalone env.
I set topic with jms templates this way:
<bean id="mm1sessionsTopicSendingTemplate" class="org.springframework.jndi.JndiObjectFactoryBean"
depends-on="jmsServerManagerImpl">
<property name="jndiName">
<value>/topic/mm1sessionsTopic</value>
</property>
</bean>
For this topic I set MDB with DefaultMessageListenerContainer this way:
<bean id="mm1sessionDispatcherListener"
class="org.springframework.jms.listener.DefaultMessageListenerContainer">
<property name="connectionFactory" ref="connectionFactory" />
<property name="pubSubDomain" value="true" />
<property name="concurrentConsumers" value="1" />
<property name="destination" ref="mm1sessionsTopicSendingTemplate" />
<property name="messageListener" ref="mm1SessionMDB" />
<property name="sessionAcknowledgeModeName" value="AUTO_ACKNOWLEDGE" />
</bean>
In this way I must set mm1SessionMDB in advanced via xml:
<bean id="mm1SessionMDB" class="com.mdb.SessionMDB">
<property name="feedPropertiesDTO" ref="feedListenerMarketMaker1Properties" />
</bean>
But I need my application to create the MDB instances programmaticly.
I mean i want to create the mdb's via the code since each MDB will have different validation values for the messages that it will retrieve from the topic(via the feedPropertiesDTO)
basically I will have pool of MDB's with the same logic but each one will have different properties. the creation time of the MDB'S must be on runtime.
is that possible?
thanks,
ray.
I think you can use factory method for instantating your MDB bean and use method
Object getBean(String name, Object... args) throws BeansException;
of the ApplicationContext in your code to instantiate bean frogramatically.
As I know this method allows you to path argument to factory method.
Here what is said in java doc for this method:
Return an instance, which may be shared or independent, of the specified bean.
Allows for specifying explicit constructor arguments / factory method
arguments, overriding the specified default arguments (if any) in the
bean definition.
I have never used this approach but I think it colud work for your case.
EDIT.
Here is an example that demonstrates about what I'm talkin (It is very simple but I don't have enough time to write more complicated).
Suppose that have interface and two it's implementations:
public interface StringMakerInterface {
// Just return simple String depending on concrete implementation.
String returnDummyString();
}
public class StringMakerImpl1 implements StringMakerInterface {
public String returnDummyString() {
return "test bean impl 1";
}
}
public class StringMakerImpl2 implements StringMakerInterface{
public String returnDummyString() {
return "test bean impl 2";
}
}
And we have one class that uses concrete implementation of this interface and to which we should dinamically inject conctrete implementation:
public class StringPrinter {
private StringMakerInterface stringMaker;
public StringMakerInterface getStringMaker() {
return stringMaker;
}
public void setStringMaker(StringMakerInterface stringMaker) {
this.stringMaker = stringMaker;
}
public StringPrinter() {
}
// Just print dummy string, returned by implementation
public void printString() {
System.out.println(stringMaker.returnDummyString());
}
}
Here is configuration class for my example:
#Configuration
public class TestFactoryMethodConfig {
#Bean(name = "stringMaker1")
public StringMakerImpl1 stringMaker1() {
return new StringMakerImpl1();
}
#Bean(name = "stringMaker2")
public StringMakerImpl2 stringMaker2() {
return new StringMakerImpl2();
}
#Bean(name = "stringPrinter")
#Scope(value = "prototype")
public StringPrinter stringPrinter(#Qualifier("stringMaker1") StringMakerInterface stringMaker) {
StringPrinter instance = new StringPrinter();
instance.setStringMaker(stringMaker);
return instance;
}
}
And here is a test case that demonstrates dinamically injection at the runtime:
#RunWith(value = SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes={TestFactoryMethodConfig.class})
public class TestFactoryMethod {
#Autowired
private ApplicationContext applicationContext;
#Resource(name = "stringMaker1")
private StringMakerInterface stringMaker1;
#Resource(name = "stringMaker2")
private StringMakerInterface stringMaker2;
#Test
public void testFactoryMethodUsage() {
StringPrinter stringPrinter1 = (StringPrinter) applicationContext.getBean("stringPrinter", stringMaker1);
StringPrinter stringPrinter2 = (StringPrinter) applicationContext.getBean("stringPrinter", stringMaker2);
stringPrinter1.printString();
stringPrinter2.printString();
}
}
My homecontroller has a UserService object that gets wired using spring correctly (it renders the index page just fine using a method no UserService).
Now I setup hibernate, so inside UserService I have a UserDao object that I am trying to wire using spring.
#Service
public class UserServiceImpl implements UserService{
UserDao userDao;
public String sayHello() {
return "hello from user service impl part 2";
}
public String getTestUser() {
return userDao.getById(1L).getUsername();
}
}
So my HomeController was calling the 'sayHello' method and it was working fine like I said.
#Controller
public class HomeController {
#Autowired
private UserService userService;
#RequestMapping("/")
public ModelAndView Index() {
ModelAndView mav = new ModelAndView();
mav.setViewName("index");
mav.addObject("message", userService.sayHello());
mav.addObject("username", userService.getTestUser());
//userService.getTestUser();
return mav;
}
The call to userService.getTestUser() fails, as the UserDao is null.
My app-config.xml is:
<!-- Hibernate SessionFactory -->
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<!--<property name="packagesToScan" value="com.blah.core.db.hibernate"/> -->
<property name="configLocation" value="/WEB-INF/classes/hibernate.cfg.xml"/>
<property name="hibernateProperties">
<value>
hibernate.dialect=org.hibernate.dialect.MySQLDialect
hibernate.connection.url=jdbc:mysql://localhost/blah
hibernate.connection.username=dbuser
hibernate.connection.password=123
hibernate.query.substitutions=true 'Y', false 'N'
hibernate.cache.use_query_cache=true
hibernate.cache.use_second_level_cache=true
hibernate.cache.provider_class=org.hibernate.cache.EhCacheProvider
hibernate.jdbc.batch_size=0
</value>
</property>
</bean>
<!-- Transaction manager for a single Hibernate SessionFactory (alternative to JTA) -->
<bean id="userDao" class="com.blah.core.db.hibernate.UserDaoImpl">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
Why is my UserDao null? I must be doing something wrong with the wiring?
Also, if I uncomment out the name=packagesToScan line, do I really need to define a bean for each Dao like I did with UserDao? Will the sessionFactory get wired somehow?
Add #AutoWired annotation to userDao.
#Service
public class UserServiceImpl implements UserService{
#AutoWired
UserDao userDao;
...
}
And make sure you have set up <context:component-scan/> to scan the packages that your #Services and #Controllers are in.
As krock mentioned, your UserDao is not being "wired" properly inside your UserService. Did you even try his suggestion ?