I have something like this:
class MyBean {
#Autowired
#Qualifier("jdbcTemplate")
#BeanProperty
var jdbcTemplate : JdbcTemplate = null
}
Spring complains that it can't find a bean of type JdbcTemplate and refuses to autowire. My spring.xml has:
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.simple.SimpleJdbcTemplate">
<constructor-arg ref="dataSource" />
</bean>
If I change the type of jdbcTemplate in MyBean from JdbcTemplate to SimpleJdbcTemplate then it works. My question is why is it apparently ignoring the Qualifier annotation? Am I doing something wrong?
It has nothing to do with #Qualifier. SimpleJdbcTemplate is not a subclass of JdbcTemplate, therefore it cannot be injected into a field of type JdbcTemplate.
Related
If i do the code in controller with
final DataSource dataSource = (DataSource) getApplicationContext().getBean("dataSource", DataSource.class);
final JdbcTemplate jdbcTemplate = new JdbcTemplate(jdbcDataSource);
final NamedParameterJdbcTemplate namedParameterJdbcTemplate = new NamedParameterJdbcTemplate(jdbcTemplate);
This will work fine
If i have to attain the same in Spring application context
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate" autowire="constructor" />
<bean class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate"
id="namedParameterJdbcTemplate">
<constructor-arg ref="jdbcTemplate" />
</bean>
In Hibernate Repository Class
private NamedParameterJdbcTemplate namedParameterJdbcTemplate;
public void setNamedParameterJdbcTemplate(NamedParameterJdbcTemplate namedParameterJdbcTemplate) {
this.namedParameterJdbcTemplate = namedParameterJdbcTemplate;
}
This throws error
Is there any way to make the object namedParameterJdbcTemplate working in Repository class
If you've declared your jdbcTemplate in your XML, that is all you should need.
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource" />
</bean>
You do need to set the datasource on the JdbcTemplate though.
Once you autowire the JdbcTemplate into your DAO, you should be able to use that to create a NamedParameterJdbcTemplate.
#Repository
public class DAOImpl implements DAO {
#Autowired
private JdbcTemplate jdbcTemplate;
public void foo() {
NamedParameterJdbcTemplate namedParameterJdbcTemplate = new NamedParameterJdbcTemplate(jdbcTemplate);
....
}
}
You need to actually create an instance of it before you use it.
If you want to use XML to create your instance you can do that too, but you'll need to autowire in the instance that gets created by the XML.
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource" />
</bean>
<bean id="namedParamterJdbcTemplate" class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">
<constructor-arg ref="jdbcTemplate"/>
</bean>
Then you should only have to autowire in the NamedParameterJdbcTemplate into your DAO.
I was searching for how entity manager is injected into DAO classes when I configure LocalContainerEntityManagerFactoryBean class in spring.
class OrderDAOImpl {
#PersistenceContext
private EntityManager entityManager
//....DAO Methods...
}
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
.....
</bean>
From this bean, how spring creates entityManager.
I was searching the same reason for hibernate's session factory and I found Here that getObject method will inject sessionFactory. But same is not the case with LocalContainerEntityManagerFactoryBean. Can some one please help me understand how this entityManager is injected in JPA?
I'm new to Spring development.And right now,i'm really facing a problem.Here are the code snippets to make you realize my problem clearly.............
Here is my DAO class:
public class LoginDaoImpl {
private DataSource dataSource;
private JdbcTemplate jdbcTemplate;
public void setDataSource(DataSource dataSource) {
this.dataSource = dataSource;
}
public int checkLoginDetails(LoginVo loginVo){
String sql = "select count(*) from empsctygrp where username=? and password=?";
jdbcTemplate = new JdbcTemplate(dataSource);
int count = jdbcTemplate.queryForObject(sql,new Object[]{loginVo.getUserName(),loginVo.getPassword()},Integer.class);
return count;
}
}
Now here is my Business-Object(BO) class:
public class LoginBo {
LoginDaoImpl loginDaoImpl = new LoginDaoImpl();
public int checkLoginDetails(LoginVo loginVo){
return loginDaoImpl.checkLoginDetails(loginVo);
}
}
Now,here is my dispatcher-servlet xml code:
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"/>
<property name="url" value="jdbc:oracle:thin:#117.194.83.9:1521:XE"/>
<property name="username" value="system"/>
<property name="password" value="password1$"/>
</bean>
<bean id="loginDaoImpl" class="com.abhinabyte.dao.LoginDaoImpl">
<property name="dataSource" ref="dataSource" />
</bean>
Now whenever i'm trying to run this on server the following exception is given:
SEVERE: Servlet.service() for servlet [dispatcher] in context with path [/A] threw exception [Request processing failed; nested exception is java.lang.IllegalArgumentException: Property 'dataSource' is required] with root cause
java.lang.IllegalArgumentException: Property 'dataSource' is required
Please help me solve this problem.............:(
Try this in LoginBo class:
#Autowired
LoginDaoImpl loginDaoImpl;
instead of
LoginDaoImpl loginDaoImpl = new LoginDaoImpl();
The problem is that you manually instantiate LoginDaoImpl.
I was having the same problem and could not find a comprehensive answer on the web, so I decided to post one here for anyone else, or for future me.
I'm still learning so if you think I have made a mistake below, please feel free to edit.
Summary:
Include <integration:annotation-config/> <context:component-scan base-package="myproject"/> in your servlet to pick up annotations
Configure JUnit tests with #RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration("file:WEB-INF/FinanceImportTool-servlet.xml")
Don't autowire dataSource or jdbcTemplate if these fields are already provided by a parent class e.g. StoredProcedure
Don't use new() as this initializes classes outside the applicationContext
Beware of using properties in your constructor which have not yet been set - obvious but embarrassingly easy to do
My original class (now altered):
public class MyDAOImpl extends StoredProcedure implements MyDAO {
private static final String SPROC_NAME = "dbo.MySP";
public MyDAOImpl(DataSource dataSource) {
super(dataSource, SPROC_NAME);
// ...declared parameters...
compile();
}
}
MyProject-servlet.xml file (only relevant bits included):
<!-- Used by Spring to pick up annotations -->
<integration:annotation-config/>
<context:component-scan base-package="myproject"/>
<bean id="MyDAOBean" class="myproject.dao.MyDAOImpl" >
<constructor-arg name="dataSource" ref="myDataSource"/>
</bean>
<!-- properties stored in a separate file -->
<bean id="myDataSource" class="com.microsoft.sqlserver.jdbc.SQLServerDataSource">
<property name="databaseName" value="${myDataSource.dbname}" />
<property name="serverName" value="${myDataSource.svrname}" />
<!-- also loaded portNumber, user, password, selectMethod -->
</bean>
Error: property 'dataSource' is required, or NullPointerException (1)
Other answers say make sure you have passed dataSource as a <property> for your bean in the servlet, etc.
I think #Abhinabyte the OP needed to annotate his setDataSource() method with #Annotation, and use <integration:annotation-config/> <context:component-scan base-package="myproject"/> in his servlet to successfully pass in dataSource as a dependency to LoginDaoImpl.
In my case, I tried adding 'dataSource' as a property and autowiring it. The "dataSource is required" error message became a NullPointerException error.
I realised after far too long that MyDAOImpl extends StoredProcedure.
dataSource was already a property of StoredProcedure. By having a dataSource property for MyDAOImpl, the autowiring was not picking up and setting the dataSource property of StoredProcedure, which left dataSource for StoredProcedure as null.
This was not picked up when I tested the value of MyDAOImpl.dataSource, as of course by now I had added a MyDAOImpl.dataSource field that had been autowired successfully. However the compile() method inherited from StoredProcedure used StoredProcedure.dataSource.
Therefore I didn't need public DataSource dataSource; property in MyDAOImpl class. I just needed to use the StoredProcedure constructor with super(dataSource, sql); in the constructor for MyDAOImpl.
I also didn't need a MyDAOImpl.jdbcTemplate property. It was set automatically by using the StoredProcedure(dataSource, sql) constructor.
Error: NullPointerException (2)
I had been using this constructor:
private static final String SPROC_NAME = "dbo.MySP";
public MyDAOImpl(DataSource dataSource) {
super(dataSource, SPROC_NAME);
}
This caused a NullPointerException because SPROC_NAME had not been initialized before it was used in the constructor (yes I know, rookie error). To solve this, I passed in sql as a constructor-arg in the servlet.
Error: [same error message appeared when I had changed file name]
The applicationContext was referring to the bin/ instances of my beans and classes. I had to delete bin/ and rebuild the project.
My new class:
public class MyDAOImpl extends StoredProcedure implements MyDAO {
#Autowired // Necessary to prevent error 'no default constructor found'
public MyDAOImpl(DataSource dataSource, String sql) {
super(dataSource, sql);
// ...declared parameters...
compile();
}
New MyProject-servlet.xml file (only relevant bits included):
<!-- Used by Spring to pick up annotations -->
<integration:annotation-config/>
<context:component-scan base-package="myproject"/>
<bean id="myDAOBean" class="org.gosh.financeimport.dao.MyDAOImpl" >
<constructor-arg name="dataSource" ref="reDataSource"/>
<constructor-arg name="sql" value="dbo.MySP" />
</bean>
<!-- properties stored in a separate file -->
<bean id="myDataSource" class="com.microsoft.sqlserver.jdbc.SQLServerDataSource">
<property name="databaseName" value="${myDataSource.dbname}" />
<property name="serverName" value="${myDataSource.svrname}" />
<!-- also loaded portNumber, user, password, selectMethod -->
</bean>
Helpful places:
If you can get past the rage, this answer on Spring forums might help too
This answer gives a broad introduction to Spring configuration
This answer has simple but useful suggestions
You should annotate that beans that will suffer IoC. Like
#Bean public class LoginDAOImpl { #Inject DataSource dataSource;......}
You set up in spring context this beans, but, you're not using them.
OBS:
When I use the JDBCTemplate I configure de IoC of JDBC like
<bean id="dataSourcePerfil" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${br.com.dao.jdbc.driver}" />
<property name="url" value="${br.com.dao.jdbc.url}" />
<property name="username" value="${br.com.dao.jdbc.user}" />
<property name="password" value="${br.com.dao.jdbc.pass}" />
</bean>
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<constructor-arg ref="dataSourcePerfil" />
</bean>
then.... after at all
#Bean
public class LoginDAOImpl {
#Autowired
private JdbcTemplate jdbcTemplate;
#Override
public List<ClienteReport> getClientes() {
return Collections<ClienteReport>. emptyList();
}
}
I have the bean config:
<bean id="PostLoginUpdater" class="xyz.auth.PostLoginUpdater" autowire="byType" />
and
public class PostLoginUpdater implements PostLoginStatePersonalizer {
//#Qualifier("CustomerManager")
#Inject
//#Resource(name = "CustomerManager")
private CustomerManager customerManager;
public void setCustomerManager(CustomerManager customerManager)
{
this.customerManager = customerManager;
}
}
Because there are two beans that implement CustomerManager I get this error:
No unique bean of type [CustomerManager] is defined: expected single
matching bean but found 2
As you can see, I'v tried several combinations (#Inject along with #Qualifier, #Ressource, only #Qualifier) But I don't get rid of this error message.
According to Spring In Depth, #Qualifier can be used along with #Inject. Can't I used them together if I defined autowire="byType" in bean config?
And I don't use <context:annotation-config /> or <context:component-scan />
You should be able to use a combination of '#Inject' and '#Qualifier', if you have multiple beans of the same type. Here is how to configure it -
<bean id="PostLoginUpdater" class="xyz.auth.PostLoginUpdater" autowire="byType" />
<bean id="firstManager" class="xyz.manager.CustomerManager" autowire="byType" >
<qualifier>first</qualifier>
</bean>
<bean id="secondManager" class="xyz.manager.CustomerManager" autowire="byType" >
<qualifier>second</qualifier>
</bean>
If you had two beans of type 'CustomerManager' as shown above, you could use the snippet shown below for injection -
public class PostLoginUpdater implements PostLoginStatePersonalizer {
#Inject
#Qualifier("first")
private CustomerManager customerManager;
public void setCustomerManager(CustomerManager customerManager)
{
this.customerManager = customerManager;
}
}
Also, on a side note -
If you keep using one of the beans more often than another you could use the 'primary' attribute.
For example, in the above example, if you always tend to use 'firstManager', you could mark it as primary as shown below.
<bean id="PostLoginUpdater" class="xyz.auth.PostLoginUpdater" autowire="byType" />
<bean id="firstManager" class="xyz.manager.CustomerManager" autowire="byType" primary="true" >
</bean>
<bean id="secondManager" class="xyz.manager.CustomerManager" autowire="byType" >
<qualifier>second</qualifier>
</bean>
If you have above configuration, the following code will always injects 'firstManager' when no qualifier is used -
public class PostLoginUpdater implements PostLoginStatePersonalizer {
#Inject
private CustomerManager customerManager;
public void setCustomerManager(CustomerManager customerManager)
{
this.customerManager = customerManager;
}
}
It doesn't make any sense to try to autowire by type, and simultaneously specify a name. Choose one approach or the other.
I have also had trouble in the past trying to use #Qualifier with #Inject. One thing to note is that there are two annotations with that name, one in Spring and one in Java:
org.springframework.beans.factory.annotation.Qualifier
javax.inject.Qualifier
However, if using the spring framework one, then the suggested usage is to explicitly name your component via #Component or #Named [#Component("beanName")] (if annotated), or in the <bean> definition. Be aware that autowiring wants the bean name, not the Class name as in your example (i.e. do not use "CustomerManager"). For example, if you have two bean definitions like in Sashi's example:
<bean id="firstManager" class="xyz.manager.CustomerManager" autowire="byType" >
<qualifier>first</qualifier>
</bean>
<bean id="secondManager" class="xyz.manager.CustomerManager" autowire="byType" >
<qualifier>second</qualifier>
</bean>
then declare the field like this:
#Inject
#Qualifier("firstManager")
private CustomerManager customerManager;
I think I've read every question and answer on Spring and autowiring a servlet, both here and at springsource.org, and I still can't get it working.
All I want to do is have the datasource automatically set in my servlets. I understand that the container creates the servlet and not Spring.
Here is code from my test servlet:
package mypackage.servlets;
imports go here...
#Service
public class TestServlet extends HttpServlet
{
private JdbcTemplate _jt;
#Autowired
public void setDataSource(DataSource dataSource)
{
_jt = new JdbcTemplate(dataSource);
}
etc etc
In my applicationContext.xml I have:
<context:annotation-config />
<context:component-scan base-package="mypackage.servlets />
<import resource="datasource.xml" />
and in my datasource.xml:
<jee:jndi-lookup id="dataSource" jndi-name="java:comp/env/jdbc/db" />
If I can't get this working I'll just use WebApplicationContextUtils in the servlet's init method but I'd really like to make this work after all the reading I've been doing.
I'm using Spring 3, Java 1.6.
Thanks,
Paul
You need to replace your Servlets by Spring MVC contollers. Because Spring will not inject anything the classes (servlets) created by someone else then Spring itselfe (except #Configurable).
(To get an very simple example, take a look at the STS Spring Template Project: MVC).
What I wanted to do was get a DataSource reference in my Servlet for free, i.e. not calling a static getDatasource method on some class.
Here's what I learned and how I got it working:
Servlets cannot be configured or autowired by Spring. Servlets are created before Spring's app context is loaded. See issue SPR-7801: https://jira.springsource.org/browse/SPR-7801
What I did was create a DataSource in my applicationContext.xml and export that as a property:
<jee:jndi-lookup id="dataSource" jndi-name="java:comp/env/jdbc/db" />
<bean class="org.springframework.web.context.support.ServletContextAttributeExporter">
<property name="attributes">
<map>
<entry key="myDatasource">
<ref bean="dataSource"/>
</entry>
</map>
</property>
</bean>
In my servlet's init method I read the property:
public void init(ServletConfig config)
{
Object obj = config.getServletContext().getAttribute("myDatasource");
setDataSource((DataSource)obj);
}
public void setDataSource(DataSource datasource)
{
// do something here with datasource, like
// store it or make a JdbcTemplate out of it
}
If I'd been using DAOs instead of hitting the database from the servlets it would have been easy to wire them up for #Autowired by marking them #Configurable, and also be able to use #Transactional and other Spring goodies.