My application uses struts and spring frameworks. I have a class FormA which has an autowired property in it. When I try to instantiate it while writing unit tests I get a Null Pointer Exception. Here is my code.
My ClassA:
public class FormA{
private String propertyOne;
#Autowired
private ServiceClass service;
public FormA(){
}
}
My unit test method:
#Test
public void testFormA(){
FormA classObj = new FormA();
}
#Autowired only works when object life cycle is managed by Spring.
You'll need to run your tests with #RunWith(SpringJUnit4ClassRunner.class), and instead of instantiating FormA manually, inject it in the test class as well, using #Autowired.
When you create an object by new, autowire\inject don't work...
as workaround you can try this:
create your template bean of NotesPanel
<bean id="notesPanel" class="..." scope="prototype">
<!-- collaborators and configuration for this bean go here -->
</bean>
and create an istance in this way
applicationContext.getBean("notesPanel");
PROTOTYPE : This scopes a single bean definition to have any number of object instances.
anyway a unit test should be
Test class
#RunWith( SpringJUnit4ClassRunner.class )
#ContextConfiguration(locations = { "classpath:META-INF/your-spring-context.xml" })
public class UserServiceTest extends AbstractJUnit4SpringContextTests {
#Autowired
private UserService userService;
#Test
public void testName() throws Exception {
List<UserEntity> userEntities = userService.getAllUsers();
Assert.assertNotNull(userEntities);
}
}
your-spring-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:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
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.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
<bean id="userService" class="java.package.UserServiceImpl"/>
</beans>
Related
I have tennisCoach object created by Spring framework:
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml") ;
Coach theCoach = context.getBean("tennisCoach", Coach.class);
Can't understand why I need #Autowired annotation in TennisCoach constructor in code below. It works fine with and without #Autowired annotation.
#Component
public class TennisCoach implements Coach {
private FortuneService fortuneService;
#Autowired
public TennisCoach(FortuneService theFortuneService) {
fortuneService = theFortuneService;
}
#Override
public String getDailyWorkout() {
return "Practice your backhand volley";
}
#Override
public String getDailyFortune() {
return fortuneService.getFortune();
}
}
UPD
Content of applicationContext.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: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.xsd">
<context:component-scan base-package="com.luv2code.springdemo"></context:component-scan>
</beans>
From #Autowired Javadoc:
If a class only declares a single constructor to begin with, it will always be used, even if not annotated.
Since Spring 4.3 you don’t need the #Autowired annotation as soon as you have the only constructor in your class.
Here #Autowired is used for constructor injection. TennisCoach has a dependency on FortuneService and it is injected through constructor. I'm not sure how you have configured beans in applicationContext.xml
I have some programmatically created beans that I am initializing via AutowireCapableBeanFactory.autowireBean() as shown below:
spring.xml:
<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-3.1.xsd">
<context:annotation-config/>
<bean id="MyService" class="...">
<property name="someProp" value="primitiveValue"/>
</bean>
<bean id="MyBean" class="...">
<property name="someString" value="primitiveValue"/>
</bean>
</beans>
MyBean.java
public class MyBean implements InitializingBean {
#Autowired MyService myService;
private String someString;
public void setSomeString (String someString) {
this.someString = someString;
}
public void afterPropertiesSet () {}
}
Caller:
MyBean bean = new MyBean(arg1, arg2, arg3);
autowireCapableBeanFactory.autowireBean(bean);
This correctly autowires bean.myService as expected. However it does not populate primitive properties like bean.someString.
Looking at the docs and this answer, I though something like this would work:
MyBean bean = new MyBean(arg1, arg2, arg3);
autowireCapableBeanFactory.autowireBean(bean);
autowireCapableBeanFactory.initializeBean(bean, "name");
But alas, someString is still null. I have found lots of references stating what will not work to initialize class properties, but nothing showing what will work.
Any ideas?
Found I could use AutowireCapableBeanFactory.applyBeanPropertyValues() to accomplish what I wanted. Code to inject both #Autowired beans and primitive properties looks like this:
#Autowired AutowireCapableBeanFactory beanFactory;
...
MyBean bean = new MyBean();
beanFactory.autowireBean(bean);
beanFactory.applyBeanPropertyValues(bean, bean.getClass().getSimpleName());
I'm guessing something is wrong integrating my spring and camel contexts.
I'm unit testing a Camel Component, and I'm trying to inject a bean (MainframeEncoderProvider) generated by spring component-scan. I can see that the bean is being constructed (breakpointing an init block), and I can autowire it into ToFalinkProducerTest, but it's not getting into the camel Component. The component is instantiated via META-INF auto-discovery, if that's relevant (http://camel.apache.org/how-do-i-add-a-component.html)
Test class setup:
#RunWith(CamelSpringJUnit4ClassRunner.class)
#ContextConfiguration(locations = {"classpath*:spring-config/testContext.xml"})
public class ToFalinkProducerTest extends CamelTestSupport{
[some tests...]
#Override
protected RouteBuilder createRouteBuilder() throws Exception {
return new RouteBuilder() {
public void configure() {
//#formatter:off
from("direct:start")
.to("tofalink:x?encoderName=test")
.to("mock:result");
//#formatter:on
}
};
}
testContext:
<?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"
xmlns:camel="http://camel.apache.org/schema/spring"
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.xsd
http://camel.apache.org/schema/spring
http://camel.apache.org/schema/spring/camel-spring.xsd
">
<!-- lightweight testcontext -->
<context:annotation-config/>
<context:component-scan base-package="net.mo"/>
<camel:camelContext>
<camel:contextScan/>
</camel:camelContext>
</beans>
component:
/**
* Represents the component that manages {#link ToFalinkEndpoint}.
*/
public class ToFalinkComponent extends DefaultComponent {
#Autowired
private MainframeEncoderProvider provider;
protected Endpoint createEndpoint(String uri, String remaining, Map<String, Object> parameters) throws Exception {
Endpoint endpoint = new ToFalinkEndpoint(uri, this);
setProperties(endpoint, parameters);
return endpoint;
}
protected MainframeEncoderProvider getProvider() {
return this.provider;
}
}
Managed to fix this, after a lot of faffing around. Replaced CamelTestSupport extension with CamelSpringTestSupport, and dropped #RunWith and #ContextConfiguration. Implemented createApplicationContext() with my xml spring context file, to retain the component scanning.
left the auto-discovery mechanic in place.
Now I just have to see whether it works at runtime :/
package com.mkyong.output;
IOutputGenerator.java
public interface IOutputGenerator
{
public void generateOutput();
}
package com.mkyong.output;
OutputHelper.java
#Component
public class OutputHelper {
#Autowired
IOutputGenerator outputGenerator;
public void generateOutput() {
outputGenerator.generateOutput();
}
/*//DI via setter method
public void setOutputGenerator(IOutputGenerator outputGenerator) {
this.outputGenerator = outputGenerator;
}*/
}
package com.mkyong.output.impl;
CsvOutputGenerator.java
#Component
public class CsvOutputGenerator implements IOutputGenerator {
public void generateOutput() {
System.out.println("This is Csv Output Generator");
}
}
SpringBeans.xml
<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-2.5.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-2.5.xsd">
<context:component-scan base-package="com.mkyong" />
</beans>
i am getting this exception Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'OutputHelper' is defined
even though i have marked OutputHelper as component.
I have changed
OutputHelper output = (OutputHelper) context.getBean("OutputHelper");
to
OutputHelper output = (OutputHelper) context.getBean("outputHelper");
and it worked.
Hi i think you haven't added following in your Spring XML configuration
xmlns:mvc="http://www.springframework.org/schema/mvc"
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
<mvc:annotation-driven/>
you need to see top exception and read the whole line.
i guess there have a exception is nested exception just like #Autowired xxxxxx,meas autowired fail.
i have notice this:
#Autowired
IOutputGenerator outputGenerator;
and
#Component
public class CsvOutputGenerator implements IOutputGenerator
so, in the default, class name is used to #Autowired，you can rewrite to
#Autowired
IOutputGenerator csvOutputGenerator;
notice:
"csvOutputGenerator" first letter is lowercase
the easier option would be to enable annotations in beans already registered in the application context, means that you can just use #Autowired instead of getting manually all beans with context.getBean()
just add this line to your SpringBeans.xml
<context:annotation-config>
if you really want to understand what you are doing reading this could help.
I have 2 classes in 2 different projects, and I have some difficulties to autowire a field.
In project pack, I have this Computation class :
package fr.aaa;
#Component
public class Computation {
#Autowired
#Qualifier("curveDAO")
CurveAccess curveDAO;
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("classpath*:applicationContext.xml");
}
}
In project db, I have this CurveAccess interface :
package com.bbb
public interface CurveAccess {
// some methods
}
implemented by a CurveDAO class :
package com.bbb.impl
#Repository("curveDAO")
#Transactional("cvaTxManager")
public class CurveDAO implements CurveAccess {
// some methods
}
My applicationContext.xml file from pack project :
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:util="http://www.springframework.org/schema/util"
xmlns:security="http://www.springframework.org/schema/security" xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.0.3.xsd">
<import resource="classpath:spring/persistence.xml"/>
<context:annotation-config />
<context:component-scan base-package="fr.aaa.*, com.bbb.*"/>
<util:properties id="jdbcProps" location="jdbc.properties" />
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:configuration.properties</value>
<value>classpath:jdbc.properties</value>
</list>
</property>
</bean>
When running, I have this exception :
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'Computation': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.bbb.CurveAccess fr.aaa.Computation.curveDAO; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [com.bbb.CurveAccess] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true), #org.springframework.beans.factory.annotation.Qualifier(value=curveDAO)}
How can I solve this problem ?
Actually, your code works perfectly fine:
#SpringBootApplication
public class So21481801Application implements CommandLineRunner {
public interface CurveAccess {
String hello();
}
#Repository("curveDAO")
public class CurveDAO implements CurveAccess {
#Override
public String hello() {
return "Hello";
}
}
#Repository("curveDAOWorld")
public class CurveDAOWorld implements CurveAccess {
#Override
public String hello() {
return "World";
}
}
#Autowired
#Qualifier("curveDAO")
CurveAccess curveDAO;
#Autowired
#Qualifier("curveDAOWorld")
CurveAccess curveDAOWorld;
#Override
public void run(String... args) {
System.out.println(curveDAO.hello());
System.out.println(curveDAOWorld.hello());
}
public static void main(String[] args) {
ConfigurableApplicationContext context = SpringApplication.run(So21481801Application.class, args);
context.close();
}
}
Probably you have some problem on how you are using the component-scan configuration on XML and the Java annotations. Mix them is not a good idea.
You need a class that implements CurveAccess interface
#Component
public class CurveAccessImpl implements CurveAccess {
//methods
}
Also remove Qualifier from curveDao in Computation bean since there is no such bean with id curveDao.
#Autowired
CurveAccess curveDAO;