Spring: Can't move #Transactioanl annotation from DAO to Service layer - spring

Question

It the Transactional annotation is in the DAO layer it works, if I move it to the service layer, I get exception:
Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.adam.czibere.RestAPIController]: Illegal arguments for constructor; nested exception is java.lang.IllegalArgumentException: argument type mismatch
Here is my code:
CatalogDAOInterface:
public interface CatalogDAOInterface {
public List<Product> getAllProduct();
public List<Category> getAllCategories() ;
public List<Media> getAllMedias();
}
CatalogDAO:
#Repository
#SuppressWarnings({"unchecked", "rawtypes"})
public class CatalogDAO implements CatalogDAOInterface {
#Autowired private SessionFactory sessionFactory;
#Override
public List<Product> getAllProduct() {
Session session = sessionFactory.getCurrentSession();
List products = session.createQuery("from Product").list();
return products;
}
#Override
public List<Category> getAllCategories() {
Session session = sessionFactory.getCurrentSession();
List products = session.createQuery("from Category").list();
return products;
}
#Override
public List<Media> getAllMedias() {
Session session = sessionFactory.getCurrentSession();
List medias = session.createQuery("from Media").list();
return medias;
}
}
CatalogServiceInterface:
public interface CatalogServiceInterface {
public List<Category> getAllCategories();
public List<Product> getAllProducts();
public List<Media> getAllMedias();
}
CatalogService:
#Service
public class CatalogService implements CatalogServiceInterface{
#Autowired
private CatalogDAO catalogDAO;
#Transactinal
#Override
public List<Product> getAllProducts() {
return catalogDAO.getAllProduct();
}
#Transactinal
#Override
public List<Category> getAllCategories() {
return catalogDAO.getAllCategories();
}
#Transactinal
#Override
public List<Media> getAllMedias() {
return catalogDAO.getAllMedias();
}
}
servlet-context.xml
<?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:mvc="http://www.springframework.org/schema/mvc"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd">
<!-- Enable #Controller annotation support -->
<mvc:annotation-driven />
<!-- Handles HTTP GET requests for /resources/** by efficiently serving
up static resources in the ${webappRoot}/resources directory -->
<mvc:resources mapping="/resources/**" location="/resources/" />
<!-- Resolves views selected for rendering by #Controllers to .jsp resources
in the /WEB-INF/views directory -->
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
</bean>
<context:component-scan base-package="com.adam.czibere" />
<!-- <bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource" -->
<!-- destroy-method="close"> -->
<!-- <property name="driverClassName" value="com.mysql.jdbc.Driver" /> -->
<!-- <property name="url" value="jdbc:mysql://localhost:3306/pizzashop" /> -->
<!-- <property name="username" value="root" /> -->
<!-- <property name="password" value="czadam" /> -->
<!-- <property name="validationQuery" value="SELECT 1" /> -->
<!-- </bean> -->
<bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="net.sourceforge.jtds.jdbc.Driver" />
<property name="url" value="jdbc:jtds:sqlserver://something" />
<property name="username" value="something" />
<property name="password" value="something" />
<property name="validationQuery" value="SELECT 1" />
</bean>
<!-- Hibernate Session Factory -->
<bean id="mySessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="myDataSource" />
<property name="packagesToScan">
<array>
<value>com.adam.czibere</value>
</array>
</property>
<property name="hibernateProperties">
<value>
hibernate.dialect=org.hibernate.dialect.MySQLDialect
</value>
</property>
</bean>
<!-- Hibernate Transaction Manager -->
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="mySessionFactory" />
</bean>
<!-- Activates annotation based transaction management -->
<tx:annotation-driven transaction-manager="transactionManager" />
</beans>
The stack trace:
exception
javax.servlet.ServletException: Servlet.init() for servlet appServlet threw exception
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
java.lang.Thread.run(Thread.java:724)
root cause
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'catalogAPIController' defined in file [C:\Users\czadam\Documents\workspace 2.0\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\SalesWizard\WEB-INF\classes\com\adam\czibere\CatalogAPIController.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.adam.czibere.CatalogAPIController]: Illegal arguments for constructor; nested exception is java.lang.IllegalArgumentException: argument type mismatch
org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:288)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1035)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:939)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:631)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:588)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:645)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:449)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:133)
javax.servlet.GenericServlet.init(GenericServlet.java:160)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
java.lang.Thread.run(Thread.java:724)
root cause
org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.adam.czibere.CatalogAPIController]: Illegal arguments for constructor; nested exception is java.lang.IllegalArgumentException: argument type mismatch
org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:158)
org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:110)
org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:280)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1035)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:939)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:631)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:588)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:645)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:449)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:133)
javax.servlet.GenericServlet.init(GenericServlet.java:160)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
java.lang.Thread.run(Thread.java:724)
root cause
java.lang.IllegalArgumentException: argument type mismatch
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.lang.reflect.Constructor.newInstance(Constructor.java:526)
org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:147)
org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:110)
org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:280)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1035)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:939)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:631)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:588)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:645)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:449)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:133)
javax.servlet.GenericServlet.init(GenericServlet.java:160)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
java.lang.Thread.run(Thread.java:724)
Part of My Controller:
#Controller
#RequestMapping(value = "api", produces = "application/json")
public class CatalogAPIController {
CatalogService catalogService;
private static final int BUFFER_SIZE = 4096;
#Autowired
public CatalogAPIController(CatalogService catalogService) {
this.catalogService = catalogService;
}
// get all categories
#RequestMapping(value = "category/all", produces = "application/json;charset=UTF-8")
#ResponseBody
public String getAllCategories() {
JSONArray categoryArray = new JSONArray();
for (Category cat : catalogService.getAllCategories()) {
JSONObject categoryJSON = new JSONObject();
try {
categoryJSON.put("id", cat.getId());
categoryJSON.put("name", cat.getName());
categoryJSON.put("imageMediaID", cat.getImageMediaID());
categoryJSON.put("parentID", cat.getParent().getId());
// Media
JSONArray mediaArray = new JSONArray();
for (Media item : cat.getMedias()) {
if (item != null) {
mediaArray.put(item.getId());
}
}
categoryJSON.put("mediaIDs", mediaArray);
categoryJSON.put("modifiedDate", cat.getModifiedDate());
categoryArray.put(categoryJSON);
} catch (JSONException e) {
e.printStackTrace();
return "Error: " + e.getMessage();
}
}
return categoryArray.toString();
}
}

Answer 1

When Spring is applying the #Transactional annotation internally, it creates a proxy class which wraps your service class.
So when your service bean is created in your application context, you are getting an object that is not of type CatalogService but some Proxy$1 class.
This Proxy$1 class will not extend CatalogService but it will implement CatalogServiceInterface. Therefore, when your CatalogAPIController bean gets created, it attempts to call its constructor with your Proxy$1 object which is the wrong type as your constructor expects a class.
So if you were to change your controller to use the interface instead of the implementation, then I believe your problems will disappear. This is because Proxy$1 DOES implement CatalogServiceInterface.
The moral of the story: ALWAYS use the interface if you reference your implementation (for if you ever decide to provide a different implementation (e.g. CatalogService2 which also implements CatalogServiceInterface, you can only plug that into your CatalogAPIController if its constructor is using the interface rather than the class (and essentially this is what's happening when you specify #Transactional.
Hope that makes sense.

Answer 2

two thing caught my attention
1.
#Transactinal
is it a typo or are you importing another annotation, it should be #Transactional
2.
why aren't you using the interfaces if you're already defining them?
instead of
#Autowired
public CatalogAPIController(CatalogService catalogService) {
this.catalogService = catalogService;
}
change it to
#Autowired
public CatalogAPIController(CatalogServiceInterface catalogService) {
this.catalogService = catalogService;
}
same applies to dao interface.
I don't understand the relation between moving transactional from one place to the other. See if that helps

Answer 3

This is what I can think of with the details you've provided. I believe you don't have the CGLIB libraries on your classpath. As such, for Spring to apply #Transactional behavior, it proxies your annotated class with JDK proxies. JDK proxies use interfaces, they cannot proxy base classes. As such, the direct superclass of a proxy is java.lang.reflect.Proxy.
In this case, your CatalogService bean will be wrapped in a proxy whose class is something like Proxy$1. When Spring tries to instantiate your #Controller class, CatalogAPIController, through reflection using the constructor
#Autowired
public CatalogAPIController(CatalogService catalogService) {
this.catalogService = catalogService;
}
it will fail because the argument passed to the Constructor#newInstance(Object...) method will not match the parameter type CatalogService since Proxy$1 is not a sub type of CatalogService.
The reason this didn't happen when you were annotating the DAO, I believe is that your DAO class is not on the component-scan package that applied #Transactional behavior. So it might have appeared as though the #Transactional was working but it wasn't. Because #Transactional wasn't working, no proxy was created and therefore Spring didn't complain about injecting this field
#Autowired
private CatalogDAO catalogDAO;
in your service class.
One possible solution is to do what Luis recommended and change your parameter types to the interface as JDK proxies to implement the interfaces, ie. the interfaces are supertypes of the Proxy$1 class instance generated to wrap your bean.
Another solution is to provide the CGLIB jars on your classpath. Spring will detect them and use them. It will then be able to proxy your class by base class instead of interface. You can find the libraries here.
Don't forget to tell Spring to proxy the target class with
<tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true" />