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Spring ProxyFactoryBean #Autowired not working

I need to intercept methods from a interface, and found this implementation of MethodInterceptor, which I tested on a new spring app and worked.
The problem is, I can't seem to get it working on the spring application I need it to.
#Configuration
public class TestMethodConfig {
#Autowired
private TestService testService;
#Bean
#Primary
public ProxyFactoryBean testProxyFactoryBean() {
ProxyFactoryBean testProxyFactoryBean = new ProxyFactoryBean();
testProxyFactoryBean.setTarget(testService);
testProxyFactoryBean.setInterceptorNames("testMethodInterceptor");
return testProxyFactoryBean;
}
}
#Service
public class TestServiceImpl implements TestService{
#Override
public void testMethod(String test) {
System.out.println("testService String");
}
}
public interface TestService{
void testMethod(String test);
}
#RestController
public class Controller {
#Autowired
private TestService testProxyFactoryBean;
#GetMapping(value = "/test")
public void test(){
testProxyFactoryBean.testMethod("valor");
}
}
#Component
public class TestMethodInterceptor implements MethodInterceptor {
#Override
public Object invoke(MethodInvocation invocation) throws Throwable {
System.out.println("before method");
System.out.println("invocation: " + Arrays.toString(invocation.getArguments()));
Object retVal = invocation.proceed();
System.out.println("after method");
return retVal;
}
}
I used Spring Actuator to check the beans relations, and I found that the #Autowired TestService on Controller should be getting assigned to testProxyFactoryBean, but its getting assigned to the TestServiceImpl bean instead, so I believe there is a problem creating the proxy.

In short
I don't know how/why it was:
on a new spring app and worked.
but:
I can't seem to get it working on the spring application I need it to.
..can probably be fixed!
Make it consistent
Or:
#Configuration
public class TestMethodConfig {
#Autowired
private TestService testService;
}
...
// !!
public class TestServiceImpl implements TestService{
#Override
public void testMethod(String test) {
System.out.println("testService String");
}
}
...
#Service // !!!
public interface TestService{
void testMethod(String test);
}
...
#RestController
public class Controller {
#Autowired
private TestService testProxyFactoryBean;
...
Or: Impl!
(Use Interface and Impl consistently!)
In Detail
6.4. Using the ProxyFactoryBean to Create AOP Proxies
esp. Proxying Interfaces.
So with "least impact" (and java config), it should be:
#Configuration
public class TestMethodConfig {
// !!! Impl from component-scan (#Service), NOT interface:
#Autowired
private TestServiceImpl testServiceImpl; // or define custom, or "inline"...
#Bean
#Primary // only if you need it, better would be: distinct!
public ProxyFactoryBean testProxyFactoryBean() {
ProxyFactoryBean testProxyFactoryBean = new ProxyFactoryBean();
// !!! set proxyInterface as documented:
testProxyFactoryBean.setProxyInterface(TestService.class);
testProxyFactoryBean.setTarget(testServiceImpl);
testProxyFactoryBean.setInterceptorNames("testMethodInterceptor");
// ...
return testProxyFactoryBean;
}
}
..enjoy! ;)

How to dynamically autowire beans in Spring with annotations?

A user can write down a url, and then, depending on the pattern of the url, my interface should use the correct implementation. Therefore, want to dynamically change my Spring's bean logic execution depending on that url that my controller receives.
Here is my controller:
#PostMapping(value = "/url",
consumes = MediaType.MULTIPART_FORM_DATA_VALUE,
produces = MediaType.TEXT_HTML_VALUE)
public ResponseEntity<InputStreamResource> parseUrl(#RequestParam String url) throws IOException {
myInterface.dosomething(url);
return ResponseEntity.ok();
}
My interface :
public interface Myterface {
void myInterface(String url);
}
and my implementations:
#Service
public class myImpl1 implements myInterface {
#Override
public void doSomething(String url) {}
}
I already tried #Qualifier, but it is not dynamic. The thing is that I will have a lot of different url patterns and therefore implementations overtime, I'd like to have to add only one class per pattern and not to have to modify anything.

You can try something like this in a configuration class or you can use #Profile annotation :
#Configuration
public class MyConfig {
#Bean
public MyInterface createBean(String URL) {
MyInterface bean;
switch(URL) {
case url1:
bean = new Implementation1();
break;
case url2:
bean = new Implementation2();
break;
default: bean = new DefaultImplementation();
}
return bean;
}
}
Check this answer for more details.

How to specify which version of a concrete implementation for an abstract class to autowire in Spring?

Having the following class structure:
public abstract class A {
String someProperty = "property"
public abstract void doSomething();
}
#Service
public class Aa extends A {
#Override
public abstract void doSomething() {
System.out.println("I did");
}
}
#Service
public class Ab extends A {
#Override
public abstract void doSomething() {
System.out.println("I did something else");
}
}
I need a way to tell Spring which A concrete class to Autowire in my Foo service, based on a property in a properties file.
#Service
public class Foo {
#Autowire
private A assignMeAConcreteClass;
}
And in my properties file I have this:
should-Aa-be-used: {true, false}

Remove the #Service annotation, instead write a #Bean-annotated method in a configuration class that reads the properties, and returns the appropriate A instance.

Not a new way but in your case I think that a possible suitable way would be to use
FactoryBean in the class that wants to inject the bean conditionally.
The idea is simple : you implement FactoryBean by parameterizing it with the interface of the bean that you want to inject and override getObject() to inject the wished implementation :
public class FactoryBeanA implements FactoryBean<A> {
#Autowired
private ApplicationContext applicationContext;
#Value("${should-Aa-be-used}")
private boolean shouldBeUsed;
#Override
public A getObject() {
if (shouldBeUsed) {
return applicationContext.getBean(Aa.class));
return applicationContext.getBean(Ab.class));
}
}
But FactoryBean instances are not classic beans. You have to configure it specifically.
You could configure it in a Spring Java configuration in this way :
#Configuration
public class FactoryBeanAConfiguration{
#Bean(name = "factoryBeanA")
public FactoryBeanA factoryBeanA() {
return new FactoryBeanA();
}
#Bean
public beanA() throws Exception {
return factoryBeanA().getObject();
}
}

Inject a merged list of beans within #Configuration

First, let me introduce a few simple classes and interface to be able to describe my problem.
interface Basic { void foo(); }
interface Extended extends Basic { void bar(); }
class BasicService {
#Inject
List<Basic> basics;
void execute() {
basics.forEach(Basic::foo);
}
}
class ExtendedService {
#Inject
List<Extended> extendeds;
void execute() {
extendeds.forEach(Extended::bar);
}
}
#Configuration
class MyConfiguration {
// Assume, that Basic1 and Basic2 are implementations of Basic and
// Extended1 is an implementation of Extended
#Bean
public Basic basic1() {
return new Basic1();
}
#Bean
public Basic basic2() {
return new Basic2();
}
#Bean
public List<Extended> extendeds() {
return Arrays.asList(new Extended1("0"), new Extended1("1"), new Extended1("2"));
}
#Bean
public BasicService basicService() {
return new BasicService();
}
#Bean
public ExtendedService extendedService() {
return new ExtendedService();
}
}
I have two services that act on different level of abstraction. My problem is that I'm failing to find a way how I can inject all beans that implement the Basic interface in my BasicService. With the current implementation it only injects all Extended implementations, because I have a factory bean method that has a return type of List in its method signature.
I can not change the bean configuration in a way that all Extended beans have their own factory methods, because in my real code the number of Extended implementations is dynamically computed on runtime...
Is there a way I can configure Spring, so that it merges all beans with Basic and List<Basic> together in 1 big list that I can use in my BasicService?

I'm not sure whether there is a way to solve this implicitly, since Spring tries to find the best match, which the List bean seems to be (have you tried generics, e.g., List<? extends Basic> ?).
But you could do it programmatically, by getting the bean definitions from the ApplicationContext:
public BasicService(#Inject ApplicationContext ctx) {
Map<String, ? extends Basic> basicMap = ctx.getBeansOfType(Basic.class);
Map<String, Collection<? extends Basic>> basicCollectionMap = ctx.getBeansofType(ResolvableType.forClassWithGenerics(Collection.class, Basic.class));
// Now merge
Collection<? extends Basic> basics = basicMap.values();
basicCollectionMap.values().stream().map(l -> basics.addAll(l));
}
I just typed this here, so I hope there aren't any obvious errors.

I solved the problem by adding generic bean definitions for the Extended implementations. This can be done by adding a BeanDefinitionRegistryPostProcessor implementation to the #Configuration class as follows:
#Configuration
class MyConfiguration {
#Bean
public static ExtendedBeanFactory extendedBeanFactory() {
return new ExtendedBeanFactory();
}
}
class ExtendedBeanFactory implements BeanDefinitionRegistryPostProcessor {
#Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) {
for (int i = 0; i < 3; i++) {
GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
beanDefinition.setBeanClass(Extended1.class);
ConstructorArgumentValues args = new ConstructorArgumentValues();
args.addGenericArgumentValue(Integer.toString(i));
beanDefinition.setConstructorArgumentValues(args);
registry.registerBeanDefinition("extended_" + i, beanDefinition);
}
}
#Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
// noop
}
}
This has the advantage, that consumer classes can simply inject a list of Basic or a list of Extended as the code from the question does.

Inject spring bean dynamically

In a java-spring web-app I would like to be able to dynamically inject beans.
For example I have an interface with 2 different implementations:
In my app I'm using some properties file to configure injections:
#Determines the interface type the app uses. Possible values: implA, implB
myinterface.type=implA
My injections actually loaded conditionally relaying on the properties values in the properties file. For example in this case myinterface.type=implA wherever I inject MyInterface the implementation that will be injected will be ImplA (I accomplished that by extending the Conditional annotation).
I would like that during runtime - once the properties are changed the following will happen (without server restart):
The right implementation will be injected. For example when setting myinterface.type=implB ImplB will be injected where-ever MyInterface is used
Spring Environment should be refreshed with the new values and re-injected as well to beans.
I thought of refreshing my context but that creates problems.
I thought maybe to use setters for injection and re-use those setters once properties are re-configured. Is there a working practice for such a requirement?
Any ideas?
UPDATE
As some suggested I can use a factory/registry that holds both implementations (ImplA and ImplB) and returns the right one by querying the relevant property.
If I do that I still have the second challenge - the environment. for example if my registry looks like this:
#Service
public class MyRegistry {
private String configurationValue;
private final MyInterface implA;
private final MyInterface implB;
#Inject
public MyRegistry(Environmant env, MyInterface implA, MyInterface ImplB) {
this.implA = implA;
this.implB = implB;
this.configurationValue = env.getProperty("myinterface.type");
}
public MyInterface getMyInterface() {
switch(configurationValue) {
case "implA":
return implA;
case "implB":
return implB;
}
}
}
Once property has changed I should re-inject my environment. any suggestions for that?
I know I can query that env inside the method instead of constructor but this is a performance reduction and also I would like to think of an ider for re-injecting environment (again, maybe using a setter injection?).

I would keep this task as simple as possible. Instead of conditionally load one implementation of the MyInterface interface at startup and then fire an event that triggers dynamic loading of another implementation of the same interface, I would tackle this problem in a different way, that is much simpler to implement and maintain.
First of all, I'd just load all possible implementations:
#Component
public class MyInterfaceImplementationsHolder {
#Autowired
private Map<String, MyInterface> implementations;
public MyInterface get(String impl) {
return this.implementations.get(impl);
}
}
This bean is just a holder for all implementations of the MyInterface interface. Nothing magic here, just common Spring autowiring behavior.
Now, wherever you need to inject a specific implementation of MyInterface, you could do it with the help of an interface:
public interface MyInterfaceReloader {
void changeImplementation(MyInterface impl);
}
Then, for every class that needs to be notified of a change of the implementation, just make it implement the MyInterfaceReloader interface. For instance:
#Component
public class SomeBean implements MyInterfaceReloader {
// Do not autowire
private MyInterface myInterface;
#Override
public void changeImplementation(MyInterface impl) {
this.myInterface = impl;
}
}
Finally, you need a bean that actually changes the implementation in every bean that has MyInterface as an attribute:
#Component
public class MyInterfaceImplementationUpdater {
#Autowired
private Map<String, MyInterfaceReloader> reloaders;
#Autowired
private MyInterfaceImplementationsHolder holder;
public void updateImplementations(String implBeanName) {
this.reloaders.forEach((k, v) ->
v.changeImplementation(this.holder.get(implBeanName)));
}
}
This simply autowires all beans that implement the MyInterfaceReloader interface and updates each one of them with the new implementation, which is retrieved from the holder and passed as an argument. Again, common Spring autowiring rules.
Whenever you want the implementation to be changed, you should just invoke the updateImplementations method with the name of the bean of the new implementation, which is the lower camel case simple name of the class, i.e. myImplA or myImplB for classes MyImplA and MyImplB.
You should also invoke this method at startup, so that an initial implementation is set on every bean that implements the MyInterfaceReloader interface.

I solved a similar issue by using org.apache.commons.configuration.PropertiesConfiguration and org.springframework.beans.factory.config.ServiceLocatorFactoryBean:
Let VehicleRepairService be an interface:
public interface VehicleRepairService {
void repair();
}
and CarRepairService and TruckRepairService two classes that implements it:
public class CarRepairService implements VehicleRepairService {
#Override
public void repair() {
System.out.println("repair a car");
}
}
public class TruckRepairService implements VehicleRepairService {
#Override
public void repair() {
System.out.println("repair a truck");
}
}
I create an interface for a service factory:
public interface VehicleRepairServiceFactory {
VehicleRepairService getRepairService(String serviceType);
}
Let use Config as configuration class:
#Configuration()
#ComponentScan(basePackages = "config.test")
public class Config {
#Bean
public PropertiesConfiguration configuration(){
try {
PropertiesConfiguration configuration = new PropertiesConfiguration("example.properties");
configuration
.setReloadingStrategy(new FileChangedReloadingStrategy());
return configuration;
} catch (ConfigurationException e) {
throw new IllegalStateException(e);
}
}
#Bean
public ServiceLocatorFactoryBean serviceLocatorFactoryBean() {
ServiceLocatorFactoryBean serviceLocatorFactoryBean = new ServiceLocatorFactoryBean();
serviceLocatorFactoryBean
.setServiceLocatorInterface(VehicleRepairServiceFactory.class);
return serviceLocatorFactoryBean;
}
#Bean
public CarRepairService carRepairService() {
return new CarRepairService();
}
#Bean
public TruckRepairService truckRepairService() {
return new TruckRepairService();
}
#Bean
public SomeService someService(){
return new SomeService();
}
}
By using FileChangedReloadingStrategy your configuration be reload when you change the property file.
service=truckRepairService
#service=carRepairService
Having the configuration and the factory in your service, let you can get the appropriate service from the factory using the current value of the property.
#Service
public class SomeService {
#Autowired
private VehicleRepairServiceFactory factory;
#Autowired
private PropertiesConfiguration configuration;
public void doSomething() {
String service = configuration.getString("service");
VehicleRepairService vehicleRepairService = factory.getRepairService(service);
vehicleRepairService.repair();
}
}
Hope it helps.

If I understand you correctly then the goal is not to replace injected object instances but to use different implementations during interface method call depends on some condition at run time.
If it is so then you can try to look at the Sring TargetSource mechanism in combination with ProxyFactoryBean. The point is that proxy objects will be injected to beans that uses your interface, and all the interface method calls will be sent to TargetSource target.
Let's call this "Polymorphic Proxy".
Have a look at example below:
ConditionalTargetSource.java
#Component
public class ConditionalTargetSource implements TargetSource {
#Autowired
private MyRegistry registry;
#Override
public Class<?> getTargetClass() {
return MyInterface.class;
}
#Override
public boolean isStatic() {
return false;
}
#Override
public Object getTarget() throws Exception {
return registry.getMyInterface();
}
#Override
public void releaseTarget(Object target) throws Exception {
//Do some staff here if you want to release something related to interface instances that was created with MyRegistry.
}
}
applicationContext.xml
<bean id="myInterfaceFactoryBean" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="proxyInterfaces" value="MyInterface"/>
<property name="targetSource" ref="conditionalTargetSource"/>
</bean>
<bean name="conditionalTargetSource" class="ConditionalTargetSource"/>
SomeService.java
#Service
public class SomeService {
#Autowired
private MyInterface myInterfaceBean;
public void foo(){
//Here we have `myInterfaceBean` proxy that will do `conditionalTargetSource.getTarget().bar()`
myInterfaceBean.bar();
}
}
Also if you want to have both MyInterface implementations to be Spring beans, and the Spring context could not contains both instances at the same time then you can try to use ServiceLocatorFactoryBean with prototype target beans scope and Conditional annotation on target implementation classes. This approach can be used instead of MyRegistry.
P.S.
Probably Application Context refresh operation also can do what you want but it can cause other problems such as performance overheads.

This may be a duplicate question or at least very similar, anyway I answered this sort of question here: Spring bean partial autowire prototype constructor
Pretty much when you want a different beans for a dependency at run-time you need to use a prototype scope. Then you can use a configuration to return different implementations of the prototype bean. You will need to handle the logic on which implementation to return yourself, (they could even be returning 2 different singleton beans it doesn't matter) But say you want new beans, and the logic for returning the implementation is in a bean called SomeBeanWithLogic.isSomeBooleanExpression(), then you can make a configuration:
#Configuration
public class SpringConfiguration
{
#Bean
#Autowired
#Scope("prototype")
public MyInterface createBean(SomeBeanWithLogic someBeanWithLogic )
{
if (someBeanWithLogic .isSomeBooleanExpression())
{
return new ImplA(); // I could be a singleton bean
}
else
{
return new ImplB(); // I could also be a singleton bean
}
}
}
There should never be a need to reload the context. If for instance, you want the implementation of a bean to change at run-time, use the above. If you really need to reload your application, because this bean was used in constructors of a singleton bean or something weird, then you need to re-think your design, and if these beans are really singleton beans. You shouldn't be reloading the context to re-create singleton beans to achieve different run-time behavior, that is not needed.
Edit The first part of this answer answered the question about dynamically injecting beans. As asked, but I think the question is more of one: 'how can I change the implementation of a singleton bean at run-time'. This could be done with a proxy design pattern.
interface MyInterface
{
public String doStuff();
}
#Component
public class Bean implements MyInterface
{
boolean todo = false; // change me as needed
// autowire implementations or create instances within this class as needed
#Qualifier("implA")
#Autowired
MyInterface implA;
#Qualifier("implB")
#Autowired
MyInterface implB;
public String doStuff()
{
if (todo)
{
return implA.doStuff();
}
else
{
return implB.doStuff();
}
}
}

You can use #Resource annotation for injection as originally answered here
e.g.
#Component("implA")
public class ImplA implements MyInterface {
...
}
#Component("implB")
public class ImplB implements MyInterface {
...
}
#Component
public class DependentClass {
#Resource(name = "\${myinterface.type}")
private MyInterface impl;
}
and then set the implementation type in properties file as -
myinterface.type=implA

Be aware that - if interesting to know about - FileChangedReloadingStrategy makes your project highly dependent on the deployment conditions: the WAR/EAR should be exploded by container and your should have direct access to the file system, conditions that are not always met in all situations and environments.

You can use Spring #Conditional on a property value. Give both Beans the same name and it should work as only one Instance will be created.
Have a look here on how to use #Conditional on Services and Components:
http://blog.codeleak.pl/2015/11/how-to-register-components-using.html

public abstract class SystemService {
}
public class FooSystemService extends FileSystemService {
}
public class GoSystemService extends FileSystemService {
}
#Configuration
public class SystemServiceConf {
#Bean
#Conditional(SystemServiceCondition.class)
public SystemService systemService(#Value("${value.key}") value) {
switch (value) {
case A:
return new FooSystemService();
case B:
return new GoSystemService();
default:
throw new RuntimeException("unknown value ");
}
}
}
public class SystemServiceCondition implements Condition {
#Override
public boolean matches(ConditionContext conditionContext, AnnotatedTypeMetadata annotatedTypeMetadata) {
return true;
}
}