Spring MVC 4.3.29 and Java 8 (current platform constraints), and mostly XML configuration, except for some Controller classes that are annotation-scanned.
In short, I want to get the ObjectMapper instance being used automatically by Spring JSON deserialization, and I want to set its FAIL_ON_UNKNOWN_PROPERTIES back to true.
I see several related questions, but all the examples seem to be Spring Boot and/or Java configuration. And none of the suggested #Autowired beans (Mapper, Builder, etc.) have any values at all in my WebSphere environment.
Hopefully I'm just missing some simple glue somewhere.
Edit: Bah, I thought I had it with this:
#Configuration
public class CustomWebConfiguration extends WebMvcConfigurerAdapter {
#Override
public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
for (HttpMessageConverter<?> converter : converters) {
if (converter instanceof MappingJackson2HttpMessageConverter) {
((MappingJackson2HttpMessageConverter) converter).getObjectMapper().
enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
break;
}
}
}
}
And with my debugger I can see that it is being hit and changing the expected flag. But when used, the behavior is not in effect. I no longer have any XML overrides in place, but I do still have the "master" <mvc:annotation-driven/> there. I wonder if those are confusing each other...
Ok, yes, this works as long as it's combined with #EnableWebMvc rather than <mvc:annotation-driven/>:
#EnableWebMvc
#Configuration
public class CustomWebConfiguration extends WebMvcConfigurerAdapter {
#Override
public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
for (HttpMessageConverter<?> converter : converters) {
if (converter instanceof MappingJackson2HttpMessageConverter) {
((MappingJackson2HttpMessageConverter) converter).getObjectMapper().
enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
break;
}
}
}
}
This kind-of "works", but by completely replacing Spring's ObjectMapper, Which then loses any other customizations it has, which I really don't want to do.
From this answer:
<bean id="myObjectMapper" class="com.fasterxml.jackson.databind.ObjectMapper"/>
<mvc:annotation-driven>
<mvc:message-converters>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper" ref="myObjectMapper"/>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
And then I could #Autowired inject those objects and mess with them, but in this case I wouldn't need to because just a new default Jackson ObjectMapper actually restores the behavior I'm wanting.
Related
In older Spring MVC apps, where you'd specify application.xml and declare your app's beans so that Spring DI could instantiate them and wire them together, you might have something like this:
<bean id="chargeFactory" class="com.example.myapp.ChargeFactory" />
<bean id="paymentService" class="com.example.myapp.DefaultPaymentService">
<ref id="chargeFactory"/>
</bean>
<bean id="chargeAuditor" class="com.example.myapp.ChargeAuditor">
<ref id="chargeFactory"/>
</bean>
Which might help wire up the following code:
public interface PaymentService {
public void makePayment(Payment payment);
}
public class DefaultPaymentService implements PaymentService {
#Autowired
private ChargeFactory chargeFactory;
#Override
public void makePayment(Payment payment, String key) {
Charge charge = chargeFactory.createCharge(key);
charge.doCharge(payment);
}
}
public class ChargeAuditor {
#Autowired
private ChargeFactory chargeFactory;
public void auditAllCharges(String key) {
List<Charge> charges = chargeFactory.getAllCharges(key);
// blah whatever
}
}
How do you accomplish the same bean wiring in Spring Boot with the #Configuration class? For example:
#Configuration
public class MyAppInjector {
#Bean
public ChargeFactory chargeFactory() {
return new ChargeFactory();
}
#Bean
public PaymentService paymentService() {
return new DefaultPaymentService(chargeFactory());
}
#Bean
public ChargeAuditor chargeAuditor() {
return new ChargeAuditor(chargeFactory());
}
}
This might work but introduces some issues:
It would force me to have to write value constructors for all my classes, which goes against everything I see in literally every tutorial/article I've come across. Plus, if I had to do that, then there's no real value to #Autowired anyways...
At this point I'm essentially doing "DIY DI", which is OK, except I'm trying to deliberately use Spring DI :-)
Every time I call chargeFactory() I'm getting a new (prototype-style) ChargeFactory instance. Maybe I want a singleton. Using this approach I have to hand-roll my own singleton implementation.
Sure, I can do all of this, but I feel like I'm flagrantly misusing/misunderstanding how #Configuration is supposed to be used, because it seems like I'm introducing a whole lot of DIY/homegrown code to solve something Spring DI should be able to do for me.
How would I reference the chargeFactory bean and wire it into both the "provider methods" for the paymentService and chargeAuditor beans? Again, looking for the Java-based #Configuration solution instead of writing an XML document to define the wirings.
I found this article which seems to be the only tutorial/documentation (surprisingly) on wiring Spring Boot apps via #Configuration (which leads me to believe there might be other/better methods...), but it does not address:
How to specify singleton vs prototype bean instantiation patterns
If multiple instances of a bean-class exist, how do I specify which instance gets wired into which dependency?
How do I get around not defining value constructors for all my classes, and just let Spring/#Autowired inject fields automagically?
When you call chargeFactory() , spring won't create new instance everytime. Give it a try and see. Same object will be returned. Anyways
You can do something like this.
#Bean
public PaymentService paymentService(ChargeFactory chargeFactory) { return new DefaultPaymentService(chargeFactory); }
I'm trying to convert a Spring project from XML to Java config and have run into the following issue with HandlerInterceptors:
XML Config (works):
<mvc:annotation-driven />
<mvc:interceptors>
<bean class="com.mycompany.MyHandlerInterceptor" />
</mvc:interceptors>
Java Config (interceptor is never called)
#Configuration
public class MvcConfig extends WebMvcConfigurationSupport {
#Override
protected void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new MyHandlerInterceptor());
}
// ...
}
According to the documentation, these two configurations should be equivalent, however in the Java config example the neither the pre or post handle methods are ever called?
What am I missing?
Thanks.
This was my own fault. I had overridden requestMappingHandlerMapping() in my MVC Java config and did not set the interceptors property on the custom HandlerMapping class.
#Bean
#Override
public RequestMappingHandlerMapping requestMappingHandlerMapping() {
CustomRequestHandlerMapping handlerMapping = new CustomRequestHandlerMapping();
handlerMapping.setOrder(0);
handlerMapping.setInterceptors(getInterceptors()); // <-- This was missing
return handlerMapping;
}
I have log4j DailyRollingFileAppender class in which setFile() method I need to check database value to decide which file to used for logging.
DailyRollingFileAppender class
public void setFileName()
{
isLoginEnabled = authenticationManager.checkLoginLogging();
}
Here 'authenticationManager' is object of class used to make database call using spring dependency injection feature.
spring-beans.xml
<bean id="dailyRollingFileAppender" class="com.common.util.DailyRollingFileAppender">
<property name="authenticationManager">
<ref bean="authenticationManager"/>
</property>
</bean>
<bean id="authenticationManager" class="com.security.impl.AuthenticationManagerImpl">
<property name="userService">
<ref bean="userService"/>
</property>
</bean>
Now when I start my application log4j gets initiated first and since spring-beans is yet to invoked it throws NullPointerException in method setFileName().
So is there a way I can make call to 'authenticationManager.checkLoginLogging();' from DailyFileAppender class so that when log4j loads it should able to get database value?
A few years late, but I hope this is of help to someone.
I was after similar functionality - I have a custom appender, and i wanted to use an autowired bean to perform some logging using a service we'd built. By making the appender implement the ApplicationContextAware interface, and making the field that i'd normally autowire static, i'm able to inject the spring-controlled bean into the instance of the appender that log4j has instantiated.
#Component
public class SslErrorSecurityAppender extends AppenderSkeleton implements ApplicationContextAware {
private static SecurityLogger securityLogger;
#Override
protected void append(LoggingEvent event) {
securityLogger.log(new SslExceptionSecurityEvent(SecurityEventType.AUTHENTICATION_FAILED, event.getThrowableInformation().getThrowable(), "Unexpected SSL error"));
}
#Override
public boolean requiresLayout() {
return false;
}
#Override
public synchronized void close() {
this.closed = true;
}
#Override
public void setApplicationContext(ApplicationContext applicationContext) {
if (applicationContext.getAutowireCapableBeanFactory().getBean("securityLogger") != null) {
securityLogger = (SecurityLogger) applicationContext.getAutowireCapableBeanFactory().getBean("securityLogger");
}
}
}
The situation here is that I have an interface that has dynamic implementations. These implementations need to be instantiated at runtime and used by injecting the interface:
public interface Configuration {
void doStuff();
}
public interface ExampleConfiguration extends Configuration {
void doStuff();
}
ExampleConfiguration has an implementation generated dynamically. I.e, there is no ExampleConfigurationImpl class. This is proving difficult to integrate into Spring because I want to have these generated implementations injected automatically:
#Autowired
private ExampleConfiguration config;
I went down the road of adding a BeanPostProcessor but it looks like unresolved dependencies don't go through there (as I would expect).
Essentially, is there a way to contribute a factory that will be called (with contextual information such as a DependencyDescriptor instance) in an attempt to resolve a missing dependency? There will be multiple interfaces extending the Configuration interface.
Spring version is 3.0.3.
Have you tried a FactoryBean?
public class ExampleConfigurationFactoryBean implements FactoryBean<ExampleConfiguration> {
#Override
public ExampleConfiguration getObject() throws Exception {
return //...magic here
}
#Override
public Class<?> getObjectType() {
return ExampleConfiguration.class;
}
#Override
public boolean isSingleton() {
return true;
}
}
I don't know how you actually create these dynamic beans (I suspect some dynamic proxy being involved), but insert your logic in magic here placeholder. Should work. You use the FactoryBean as if it had a target type in your XML:
<bean id="exampleConfigurationFactoryBean" class="ExampleConfigurationFactoryBean"/>
<bean id="someBean">
<!-- exampleConfiguration is of ExampleConfiguration type -->
<property name="exampleConfiguration" ref="exampleConfigurationFactoryBean"/>
</bean>
Spring will call getObject() when requested.
I assume you've got some way to actually manufacture the instances? Well, all you need to do is to make that factory into a bean itself and add the right annotations:
#org.springframework.context.annotation.Configuration
public class ConfigBean {
#org.springframework.context.annotation.Bean
public ExampleConfiguration getObject() throws Exception {
return //...magic here
}
}
You use the usual Spring techniques for hooking to any configuration you need. (I assume you're using <context:component-scan> and <context:annotation-config>…)
I have a set of classes with a complex initialization scheme. Basically, I start with the interface I need to get a hold of, and then make a bunch of calls, and I end up with an object that implements that interface.
In order to handle this, I made a factory class that can, given an interface, produce the final object. I made this factory into a bean, and in XML I specified my various service beans as being instantiated via this factory object with a parameter of the interface that they will implement.
This works great, and I totally get exactly the beans I need. Unfortunately, I would like to access them from my controller classes, which are discovered via component scanning. I use #Autowired here, and it appears that Spring has no idea what type of object these are, and since #Autowired works by type, I'm SOL.
Using #Resource(name="beanName") here would work perfectly, however it seems odd to use #Resource for some beans and #Autowired for others.
Is there a way to get Spring to know what interface the factory will be creating for each of these beans without having a different factory method for each type?
I'm using Spring 2.5.6, by the way, otherwise I'd just JavaConfig the whole thing and forget about it.
Factory class:
<T extends Client> T buildService(Class<T> clientClass) {
//Do lots of stuff with client class and return an object of clientClass.
}
app context:
<bean id="serviceFactoryBean" class="com.captainAwesomePants.FancyFactory" />
<bean id="userService" factory-bean="serviceFactoryBean" factory-method="buildService">
<constructor-arg value="com.captain.services.UserServiceInterface" />
</bean>
<bean id="scoreService" factory-bean="serviceFactoryBean" factory-method="buildService">
<constructor-arg value="com.captain.services.ScoreServiceInterface" />
</bean>
my controller:
public class HomepageController {
//This doesn't work
#Autowired #Qualifier("userService") UserServiceInterface userService;
//This does
#Resource(name="scoreService") ScoreServiceInterface scoreService;
}
I suggest you take the factory pattern one step further and implement your factories as Spring FactoryBean classes. The FactoryBean interface has a getObjectType() method which the contain calls to discover what type the factory will return. This gives your autowiring something to get its teeth into, as long as your factory returns a sensible value.
I had a similar problem, but for me I wanted to use a single factory for creating mocked-out implementations of my auto-wired dependencies using JMockit (the testing framework that I am required to use).
After finding no satisfactory solution on the interwebs, I threw together a simple solution that is working really well for me.
My solution uses a Spring FactoryBean as well, but it only uses a single factory bean for creating all my beans (which the original asker seems to have wished to do).
My solution was to implement a factory-of-factories meta-factory that serves-up FactoryBean wrappers around the real, single factory.
Here is the Java for my JMockit mock bean factory:
public class MockBeanFactory<C> implements FactoryBean<C> {
private Class<C> mockBeanType;
protected MockBeanFactory(){}
protected <C> C create(Class<C> mockClass) {
return Mockit.newEmptyProxy(mockClass);
}
#Override
public C getObject() throws Exception {
return create(mockBeanType);
}
#Override
public Class<C> getObjectType() {
return mockBeanType;
}
#Override
public boolean isSingleton() {
return true;
}
public static class MetaFactory {
public <C> MockBeanFactory<C> createFactory(Class<C> mockBeanType) {
MockBeanFactory<C> factory = new MockBeanFactory<C>();
factory.mockBeanType = mockBeanType;
return factory;
}
}
}
And then in the Spring context XML file, you just can simply create the meta factory that creates the specific bean-type factories:
<bean id="metaFactory" class="com.stackoverflow.MockBeanFactory$MetaFactory"/>
<bean factory-bean="metaFactory" factory-method="createFactory">
<constructor-arg name="mockBeanType" value="com.stackoverflow.YourService"/>
</bean>
To make this work for the original asker's situation, it could be tweaked to make the FactoryBeans into wrappers/adapter for the serviceFactoryBean:
public class FancyFactoryAdapter<C> implements FactoryBean<C> {
private Class<C> clientClass;
private FancyFactory serviceFactoryBean;
protected FancyFactoryAdapter(){}
#Override
public C getObject() throws Exception {
return serviceFactoryBean.buildService(clientClass);
}
#Override
public Class<C> getObjectType() {
return clientClass;
}
#Override
public boolean isSingleton() {
return true;
}
public static class MetaFactory {
#Autowired FancyFactory serviceFactoryBean;
public <C> FancyFactoryAdapter<C> createFactory(Class<C> clientClass) {
FancyFactoryAdapter<C> factory = new FancyFactoryAdapter<C>();
factory.clientClass = clientClass;
factory.serviceFactoryBean = serviceFactoryBean;
return factory;
}
}
}
Then in the XML (notice the userServiceFactory id and the userService bean id are necessary only to work with the #Qualifier annotation):
<bean id="metaFactory" class="com.stackoverflow.FancyFactoryAdapter$MetaFactory"/>
<bean id="userServiceFactory" factory-bean="metaFactory" factory-method="createFactory">
<constructor-arg name="clientClass" value="com.captain.services.UserServiceInterface"/>
</bean>
<bean id="userService" factory-bean="userServiceFactory"/>
<bean id="scoreServiceFactory" factory-bean="metaFactory" factory-method="createFactory">
<constructor-arg name="clientClass" value="com.captain.services.ScoreServiceInterface"/>
</bean>
<bean id="scoreService" factory-bean="scoreServiceFactory"/>
And that's it, just one little Java class and a smidge of boiler-plate configuration and your custom bean factory can create all of your beans and have Spring resolve them successfully.
You should be able to achieve this using:
<bean id="myCreatedObjectBean" class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
<property name="targetClass">
<value>com.mycompany.MyFactoryClass</value>
</property>
<property name="targetMethod">
<value>myFactoryMethod</value>
</property>
</bean>
Then you can use either #Resource or #Autowired + #Qualifier to inject into your object directly.