Solve Spring NoUniqueBeanDefinitionException

I encountered the NoUniqueBeanDefinitionException where-in Spring was unable to which class to inject for an Autowired variable even though the it was properly qualified!

This happened because the Qualifier did not get post-processed and so multiple implementations of the Interface type of the variable being injected were now available in the classpath. So Spring found more that one instance and was unable to decide which instance to inject for the particular Autowired target.

The turn on the default AutowiredAnnotationBeanPostProcessor which processes the @Qualifier , you need to add the line to the beans section of your spring configuration. Since this was missing from the beans section of the configuration file, the Qualifier annotation was ignored in this code:

    @Autowired
    public void setDao(@Qualifier("myDaoImpl") MyDAO dao) {

And here is a snippet of the exception that was logged:

 java.lang.RuntimeException: org.springframework.beans.factory.BeanCreationException: Injection of autowired dependencies failed for class [class my.package.impl.name.MyBeanClassName]; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void my.package.impl.name.MyBeanClassName.setDao(my.package.intf.name.MyDAO); nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [my.package.intf.name.MyDAO] is defined: expected single matching bean but found 4: myDaoImpl,secondDaoImpl,thirdDaoImpl,fourthDaoImpl

This error was resolved after adding the below line to the beans section of spring configuration:

<context:annotation-config></context:annotation-config>

Upgrade Hibernate 3..x to Hibernate 4.3.x

NOTE: This is a partial guide to upgrade your Hibernate 3 project to Hibernate 4.3.x

Hibernate has a come a long way from version 3.x to the latest version Hibernate 4.3.x with lots of major changes, bug fixes and enhancements:

• Started using gradle for builds
• Redesign the way SessionFactory is built
• Improved metamodel
• Initial osgi-fication by package splitting (public, internal, spi)
• Migration to i18n logging framework (using jboss logging)
• JDK 1.6 (JDBC4) as baseline

The following hibernate jars are required to be downloaded from the Maven Repository:

1. hibernate-core-4.3.9.Final.jar
2. hibernate-annotations-3.5.6-Final.jar
3. hibernate-commons-annotations-3.2.0.Final.jar (DO NOT USE 3.3.0.ga version)
4. hibernate-entitymanager-4.3.9.Final.jar
5. hibernate-validator-5.1.3.Final.jar
6. jboss-logging-3.1.3.GA.jar

Do not use hibernate-commons-annotations-3.3.0.ga.jar as it is a release mistake and will create more problems.

You can download the corresponding javadoc and source files by going to the Maven website and searching for: 

g:"org.hibernate" AND a:"hibernate-core" AND v:"4.3.9.Final"

Now that all the required jars are downloaded, hibernate3.jar will need to be replaced by hibernate-core jar; here is a simple guide to when to include rest of the jars.

To resolve the below error, add hibernate-commons-annotations-3.2.0.Final.jar to classpath and the JBoss library path:

NOTE: DO NOT USE hibernate-commons-annotations-3.3.0.ga.jar as it is a release mistake

java.lang.NoClassDefFoundError: org/hibernate/annotations/common/reflection/MetadataProvider

at org.jboss.hibernate.jmx.Hibernate.buildConfiguration(Hibernate.java:194)

at org.jboss.hibernate.jmx.Hibernate.buildSessionFactory(Hibernate.java:228)

at org.jboss.hibernate.jmx.Hibernate.startService(Hibernate.java:155)

at org.jboss.system.ServiceMBeanSupport.jbossInternalStart(ServiceMBeanSupport.java:289)

at org.jboss.system.ServiceMBeanSupport.jbossInternalLifecycle(ServiceMBeanSupport.java:245)

at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

To resolve the below error, add jboss-logging-3.2.1.Final.jar to classpath and the JBoss library path:

Not resheduling failed loading task, loadTask=org.jboss.mx.loading.ClassLoadingTask@1219665{classname: org.hibernate.internal.CoreMessageLogger, requestingThread: Thread[main,5,jboss], requestingClassLoader: org.jboss.mx.loading.UnifiedClassLoader3@1b06041{ url=null ,addedOrder=2}, loadedClass: nullnull, loadOrder: 2147483647, loadException: java.lang.NoClassDefFoundError: org/jboss/logging/BasicLogger, threadTaskCount: 0, state: 1, #CCE: 1}

java.lang.NoClassDefFoundError: org/jboss/logging/BasicLogger

at java.lang.ClassLoader.defineClass1(Native Method)

at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)

at java.lang.ClassLoader.defineClass(ClassLoader.java:615)

at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)

at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)

Follow the Hibernate Code Migration Guide to make the appropriate changes as required:

1. Initial move to ServiceRegistry.  For now, see design wikis or sources for more information.  Not all "services" have been migrated to this model yet.  The main ones (JDBC and transaction stuff) as well as lowever level one (classloading and such) have been migrated.  The rest will be moved during Alpha2 development.
2. In an initial push toward osgi we started splitting up packages a little bit differently in this release. 
   1. The reason is to identify classes which are intended as
      1. public API, which are fully expected to be used in application code.
      2. internal implementation details, which are only intended for Hibernate use.
      3. SPI contracts, whch define
         1. extension contracts
         2. contracts with Hibernate internals exposed to these extensions
   2. This will potentially lead to some  packaging changes needed in user code:
      1. org.hibernate.dialect.resolver.DialectResolver -> org.hibernate.service.jdbc.dialect.spi.DialectResolver
3. Deprecated methods that have been removed:
   1. References to org.hibernate.type.AbstractSingleColumnStandardBasicType and org.hibernate.type.SingleColumnType methods should be changed as indicated:
      1. nullSafeGet(ResultSet rs, String name) should be changed to 
         nullSafeGet(ResultSet rs, String name, SessionImplementor session)
      2. get(ResultSet rs, String name) should be changed to 
         get(ResultSet rs, String name, SessionImplementor session)
      3. nullSafeSet(PreparedStatement st, T value, int index) should be changed to nullSafeSet(PreparedStatement st, Object value, int index, SessionImplementor session)
      4. set(PreparedStatement st, T value, int index) should be changed to set(PreparedStatement st, T value, int index, SessionImplementor session)
   2. References to org.hibernate.usertype.UserType methods should be changed as indicated:
      1. nullSafeGet(ResultSet rs, String[] names, Object owner) should be changed to   
         nullSafeGet(ResultSet rs, String[] names, SessionImplementor session, Object owner)
      2. nullSafeSet(PreparedStatement st, Object value, int index) should be changed to nullSafeSet(PreparedStatement st, Object value, int index, SessionImplementor session)
   3. Session.reconnect() - manual disconection and reconnection is now only supported for user-supplied-connection scenarios (JDBC Connection passed in while opening the Session)
   4. Session.connection() - use Session.doWork(), Session.doReturningWork() or Session.sessionWithOptions()...openSession() as replacement depending on need
   5. Most of the overloaded SessionFactory.openSession methods.  Use SessionFactory.withOptions()...openSession() instead
4. Deprecated classes/interfaces that have been removed:
   1. org.hibernate.classic.Session
   2. org.hibernate.classic.Validatable
   3. org.hibernate.classic.ValidationException
5. org.hibernate.jdbc.BatcherFactory, Batcher, and their implementations have been replaced by org.hibernate.engine.jdbc.batch.spi.BatchBuilder and Batch, with default implementations in org.hibernate.engine.jdbc.batch.internal. You can override the default BatchBuilder by defining the  "hibernate.jdbc.batch.builder" property as the name of a BatchBuilder implementation, or by providing a BatchBuilder in a custom ServiceRegistry.
6. hibernate.cfg.xml no longer supported as means of specifying listeners.  New approach invloves using an org.hibernate.integrator.spi.Integrator which works based on "service discovery". 

Upgrade from Spring 2.5.x to Spring 4.1.x - JBoss

After completing the steps mentioned in my previous post for Upgrading Spring 2.5.x to Spring 4.1.x, the project compiles without problems, however, JBoss deployment does not work as it does not get all the required new Spring Jars.

The Spring component jars also need to be added to the JBoss classpath. However, here are a few specific exceptions that point to requiring specific jars in the JBoss classpath as below.

To resolve the below error, add spring-context.jar to JBoss library path:
java.lang.ArrayStoreException: sun.reflect.annotation.TypeNotPresentExceptionProxy
at sun.reflect.annotation.AnnotationParser.parseClassArray(AnnotationParser.java:653)
at sun.reflect.annotation.AnnotationParser.parseArray(AnnotationParser.java:460)
at sun.reflect.annotation.AnnotationParser.parseMemberValue(AnnotationParser.java:286)
at sun.reflect.annotation.AnnotationParser.parseAnnotation(AnnotationParser.java:222)
at sun.reflect.annotation.AnnotationParser.parseAnnotations2(AnnotationParser.java:69)
at sun.reflect.annotation.AnnotationParser.parseAnnotations(AnnotationParser.java:52)
at java.lang.Class.initAnnotationsIfNecessary(Class.java:3079)


To resolve the below error, add spring-beans.jar to JBoss library path
java.lang.NoClassDefFoundError: org/springframework/beans/factory/BeanFactory
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2436)
at java.lang.Class.getDeclaredMethods(Class.java:1793)
at org.jboss.ejb3.interceptor.InterceptorInfoRepository$AnnotationInitialiser.getInfo(InterceptorInfoRepository.java:704)
at org.jboss.ejb3.interceptor.InterceptorInfoRepository.initialiseFromAnnotations(InterceptorInfoRepository.java:469)
at org.jboss.ejb3.interceptor.InterceptorInfoRepository.getOrInitialiseFromAnnotations(InterceptorInfoRepository.java:451)
at org.jboss.ejb3.interceptor.InterceptorInfoRepository.getInterceptorsFromAnnotation(InterceptorInfoRepository.java:341)
at org.jboss.ejb3.interceptor.InterceptorInfoRepository.getClassInterceptors(InterceptorInfoRepository.java:139)
at org.jboss.ejb3.EJBContainer.initialiseInterceptors(EJBContainer.java:737)
at org.jboss.ejb3.EJBContainer.getClassInterceptors(EJBContainer.java:429)

Hopefully this should resolve all issues for a successful upgrade of Spring 2.5.x to Spring 4.1.x!

EasyMock Exceptions when mocking Classes instead of Interfaces

EasyMock as the name suggests, provides an easy way to mock objects for testing where-in you mock interfaces of the classes you want to test. EasyMock then generates mock objects on the fly using Java's proxy mechanism and then simulates it in a simple way and also verifies whether it is used as expected.
When creating some new mock objects for testing using EasyMock 2.5.x, I noticed the below exceptions:

java.lang.IllegalArgumentException: org.hibernate.dialect.Dialect is not an interface
 at java.lang.reflect.Proxy.getProxyClass0(Proxy.java:470)
 at java.lang.reflect.Proxy.newProxyInstance(Proxy.java:690)
 at org.easymock.internal.JavaProxyFactory.createProxy(JavaProxyFactory.java:12)
 at org.easymock.internal.MocksControl.createMock(MocksControl.java:37)
 at org.easymock.EasyMock.createMock(EasyMock.java:43)

To solve this, change your import as:

org.easymock.EasyMock.createMock => org.easymock.classextension.EasyMock.createMock

And another set of exceptions popped up:

java.lang.IllegalArgumentException: not a proxy instance
 at java.lang.reflect.Proxy.getInvocationHandler(Proxy.java:769)
 at org.easymock.EasyMock.getControl(EasyMock.java:1336)
 at org.easymock.EasyMock.replay(EasyMock.java:1280)

To solve this, change your imports as:

org.easymock.EasyMock.replay => org.easymock.classextension.EasyMock.replay
org.easymock.EasyMock.verify => org.easymock.classextension.EasyMock.verify

Viola! and now we are good!
When mocking classes that are not an interface, we need to use the createMock, replay, and verify methods FROM the class org.easymock.classextension.EasyMock and NOT the ones we regularly use from org.easymock.EasyMock
However, since EasyMock 3.0, the separate classextension package has been deprecated and left in place for backward compatibility and the above changes are not required. So it is recommended that if possible, one should upgrade to the latest 3.x version of EasyMock instead of going for the above changes.

Oracle Date / Timestamp difference in Hours, Minutes & Seconds

Figuring out the exact time difference that has elapsed between between two Date / Timestamp columns in Oracle using SQL is not as easy as it sounds.
A simple subtraction the those values using this query yields:

SQL> select runnumber, starttime, endtime, (endtime-starttime) TotalMinutes0 from run_log;

 RUN STARTTIME            ENDTIME              TOTALMINUTES0 
---- -------------------- -------------------- ------------- 
   3 24-APR-15 12:07:49   24-APR-15 12:58:37   0.03527777778  
   2 24-APR-15 11:00:47   24-APR-15 11:55:11   0.03777777778  
   1 24-APR-15 08:00:13   24-APR-15 08:52:39   0.03641203704  

So, I convert the difference to minutes by multiplying it by 1440 (24 Hours X 60 Minutes) using this below query:

SQL> select runnumber, starttime, endtime, (endtime-starttime) TotalMinutes0, 
        to_char((endtime-starttime)*1440,'99.99') TotalMinutes1 -- OR (24 Hours X 60 Minutes)
     from run_log order by starttime desc ;

 RUN STARTTIME            ENDTIME              TOTALMINUTES0 TOTALMINUTES1 
---- -------------------- -------------------- ------------- ------------- 
   3 24-APR-15 12:07:49   24-APR-15 12:58:37   0.03527777778  50.80         
   2 24-APR-15 11:00:47   24-APR-15 11:55:11   0.03777777778  54.40         
   1 24-APR-15 08:00:13   24-APR-15 08:52:39   0.03641203704  52.43         

That's great progress, but now the seconds part is a decimal fraction instead of seconds. This necessitates the wielding of the Oracle "numtodsinterval" built-in function using this below query:

SQL> select runnumber, starttime, endtime, (endtime-starttime) TotalMinutes0,
         to_char((endtime-starttime)*1440,'99.99') TotalMinutes1,
         numtodsinterval((endtime-starttime),'day') TotalMinutes2
     from run_log order by starttime desc ;

 RUN STARTTIME            ENDTIME              TOTALMINUTES0 TOTALMINUTES1 TOTALMINUTES2 
---- -------------------- -------------------- ------------- ------------- ------------- 
   3 24-APR-15 12:07:49   24-APR-15 12:58:37   0.03527777778  50.80        0 0:50:48.0   
   2 24-APR-15 11:00:47   24-APR-15 11:55:11   0.03777777778  54.40        0 0:54:24.0   
   1 24-APR-15 08:00:13   24-APR-15 08:52:39   0.03641203704  52.43        0 0:52:26.0   

The output is good and we now only need to trim it a bit as in the below query:

SQL> select runnumber, starttime, endtime, (endtime-starttime) TotalMinutes0,
         to_char((endtime-starttime)*1440,'99.99') TotalMinutes1,
         numtodsinterval((endtime-starttime),'day') TotalMinutes2,
         substr(numtodsinterval((endtime-starttime),'day'), 4, 8) TotalMinutes3 -- Ignore hours
     from run_log order by starttime desc ;

 RUN STARTTIME            ENDTIME              TOTALMINUTES0 TOTALMINUTES1 TOTALMINUTES2 TOTALMINUTES3 
---- -------------------- -------------------- ------------- ------------- ------------- ------------- 
   3 24-APR-15 12:07:49   24-APR-15 12:58:37   0.03527777778  50.80        0 0:50:48.0   0000000       
   2 24-APR-15 11:00:47   24-APR-15 11:55:11   0.03777777778  54.40        0 0:54:24.0   0000000       
   1 24-APR-15 08:00:13   24-APR-15 08:52:39   0.03641203704  52.43        0 0:52:26.0   0000000       

Now that's really very strange - the trimming substring does not get me the expected value - wonder what's going on? To check that, we use "to_char" function to see what is happening during the conversion to string as in the below query:

SQL> select runnumber, starttime, endtime, (endtime-starttime) TotalMinutes0,
         to_char((endtime-starttime)*1440,'99.99') TotalMinutes1,
         numtodsinterval((endtime-starttime),'day') TotalMinutes2,
         substr(numtodsinterval((endtime-starttime),'day'), 4, 8) TotalMinutes3, -- Ignore hours
         to_char(numtodsinterval((endtime-starttime),'day')) TotalMinutes4
     from run_log order by starttime desc ;

 RUN STARTTIME            ENDTIME              TOTALMINUTES0 TOTALMINUTES1 TOTALMINUTES2 TOTALMINUTES3 TOTALMINUTES4                  
---- -------------------- -------------------- ------------- ------------- ------------- ------------- ------------------------------ 
   3 24-APR-15 12:07:49   24-APR-15 12:58:37   0.03527777778  50.80        0 0:50:48.0   0000000       +000000000 00:50:48.000000000  
   2 24-APR-15 11:00:47   24-APR-15 11:55:11   0.03777777778  54.40        0 0:54:24.0   0000000       +000000000 00:54:24.000000000  
   1 24-APR-15 08:00:13   24-APR-15 08:52:39   0.03641203704  52.43        0 0:52:26.0   0000000       +000000000 00:52:26.000000000  

Ahh ha! Substring converts the given value to string before getting us a part of it and the conversion to string gives us a totally different & larger string! So now we use trim the result as in the below query to get the executed final result:

SQL> select runnumber, starttime, endtime, (endtime-starttime) TotalMinutes0,
         to_char((endtime-starttime)*1440,'99.99') TotalMinutes1,
         numtodsinterval((endtime-starttime),'day') TotalMinutes2,
         substr(numtodsinterval((endtime-starttime),'day'), 4, 8) TotalMinutes3, -- Ignore hours
         to_char(numtodsinterval((endtime-starttime),'day')) TotalMinutes4,
         substr(numtodsinterval((endtime-starttime),'day'), 15, 8) TotalMinutes5 -- Ignore hours
     from run_log order by starttime desc ;

 RUN STARTTIME            ENDTIME              TOTALMINUTES0 TOTALMINUTES1 TOTALMINUTES2 TOTALMINUTES3 TOTALMINUTES4                  TOTALMINUTES5
---- -------------------- -------------------- ------------- ------------- ------------- ------------- ------------------------------ -------------
   3 24-APR-15 12:07:49   24-APR-15 12:58:37   0.03527777778  50.80        0 0:50:48.0   0000000       +000000000 00:50:48.000000000  50:48.00      
   2 24-APR-15 11:00:47   24-APR-15 11:55:11   0.03777777778  54.40        0 0:54:24.0   0000000       +000000000 00:54:24.000000000  54:24.00      
   1 24-APR-15 08:00:13   24-APR-15 08:52:39   0.03641203704  52.43        0 0:52:26.0   0000000       +000000000 00:52:26.000000000  52:26.00      

Finally! The time difference is displayed in the format HH24:MI:SS.NNN

So after five iterations, I finalize that this exercise requires using the Oracle built-in function "numtodsinterval" which takes a number of a given interval unit and converts it to an INTERVAL DAY TO SECOND literal. The interval value indicates the unit of the specified number and the case-insensitive valid values are:

• 'DAY'
• 'HOUR'
• 'MINUTE'
• 'SECOND'

In our case, the number in question is the simple difference of the two time values and its' unit is a day so the interval value is "Day".

Upgrade from Spring 2.5.x to Spring 4.1.x

I am upgrading Spring libraries of a critical project from Spring 2.5.x to the latest available release which is Spring 4.1.6 right now. One of the major issues I faced is that the packaging strategy was changed in Spring 3.0 release. Earlier, a single spring.jar with all jars and required libraries was provided, but this was discontinued from the 3.0 release. Now we would need to include each jar individually as per requirements - one jar for all situations doesn't exist anymore.

So, now you need to download individual spring component jars from the Maven Repository. The jars required are:

1. spring-aop.jar
2. spring-beans.jar
3. spring-context.jar
4. spring-core.jar
5. spring-expression.jar
6. aopalliance-1.0.jar - third-party jar

The third-party jar aopalliance-1.0 is required only if you use org.springframework.aop and it can be downloaded from here. This was earlier on bundled in the spring.jar and so now has to be added separately as required.

You can download the corresponding javadoc and source files by going to the Maven website and searching for:

• g:"org.springframework" AND v:"4.1.6.RELEASE" - for Spring components
  
• g:"aopalliance" - for aopalliance

Now that all the required jars are downloaded, spring-core jar will need to be included in most projects; here is a simple guide to when to include rest of the jars.

Add spring-beans.jar to classpath when you see the below or similar error during compilation:
Caused by: java.lang.ClassNotFoundException: org.springframework.beans.factory.NoSuchBeanDefinitionException
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)

Add spring-context.jar to classpath when you see the below or similar error during compilation:
Caused by: java.lang.ClassNotFoundException: org.springframework.context.access.ContextSingletonBeanFactoryLocator
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)

Add spring-expression.jar to classpath when you see the below or similar error during compilation:
Caused by: java.lang.ClassNotFoundException: org.springframework.expression.ParserContext
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)

Add spring-aop.jar to classpath when you see the below or similar error during compilation:
The type org.springframework.aop.TargetSource cannot be resolved. It is indirectly referenced from required .class files
OR

Caused by: java.lang.ClassNotFoundException: org.springframework.aop.framework.ProxyFactoryBean

Add aopalliance-1.0.jar to classpath when you see the below or similar error during compilation:
The type org.aopalliance.aop.Advice cannot be resolved. It is indirectly referenced from required .class files
OR

Caused by: java.lang.ClassNotFoundException: org.aopalliance.intercept.MethodInterceptor

That's it - you should be all set and upgraded to the latest version of Spring after this exercise - no code change required!