Is it possible to read property file values inside #Repository.
Any help is appreciated.
As M.Deinum mentioned in the comment section, #Repository is just a variation of #Component. You can read your property file by injecting Environment or you can just use #Value.
If you use a class repository, you can use the #Value annotation on any non-final field to have it populated automatically.
On the other hand, if you are using an interface repository, you cannot read a property directly, as you have nowhere to inject your components/values.
Anyway, I found a sort of work-around which can be used to achieve a similar result.
You start by creating a class that implements ApplicationContextProvider:
#Component
public class StaticPropertiesProvider implements ApplicationContextAware {
private static ApplicationContext applicationContext;
#Override
public void setApplicationContext(#Nonnull final ApplicationContext applicationContext) throws BeansException {
StaticPropertiesProvider.applicationContext = applicationContext;
}
public static <T> T getProperty(final String property, final Class<T> clazz) {
return applicationContext.getEnvironment().getProperty(property, clazz);
}
}
When your application starts, the static applicationContext field will be populated with your Application Context, so that you can use it afterwards from the static getProperties method.
You can then call it from a default method inside your repository, e.g.
public interface MyRepository extends MongoRepository<MyDocument, String> {
#Query(value = "{'myProperty': ?0}")
List<MyDocument> findByMyProperty(int myProperty);
default List<MyDocument> findByMyProperty() {
final var myPropertyDefault = StaticPropertiesProvider.getProperty("my.property", Integer.class);
return this.findByMyProperty(myProperty);
}
}
Clearly there should be a property name my.property with an int value inside application.properties.
(you can do the same even with JPA repositories)
Related
I am trying to autowire a component into a custom JsonDeserializer but cannot get it right even with the following suggestions I found:
Autowiring in JsonDeserializer: SpringBeanAutowiringSupport vs HandlerInstantiator
Right way to write JSON deserializer in Spring or extend it
How to customise the Jackson JSON mapper implicitly used by Spring Boot?
Spring Boot Autowiring of JsonDeserializer in Integration test
My final goal is to accept URLs to resources in different microservices and store only the ID of the resource locally. But I don't want to just extract the ID from the URL but also verify that the rest of the URL is correct.
I have tried many things and lost track a bit of what I tried but I believe I tried everything mentioned in the links above. I created tons of beans for SpringHandlerInstantiator, Jackson2ObjectMapperBuilder, MappingJackson2HttpMessageConverter, RestTemplate and others and also tried with setting the SpringHandlerInstantiator in RepositoryRestConfigurer#configureJacksonObjectMapper.
I am using Spring Boot 2.1.6.RELEASE which makes me think something might have changed since some of the linked threads are quite old.
Here's my last attempt:
#Configuration
public class JacksonConfig {
#Bean
public HandlerInstantiator handlerInstantiator(ApplicationContext applicationContext) {
return new SpringHandlerInstantiator(applicationContext.getAutowireCapableBeanFactory());
}
}
#Configuration
public class RestConfiguration implements RepositoryRestConfigurer {
#Autowired
private Validator validator;
#Autowired
private HandlerInstantiator handlerInstantiator;
#Override
public void configureValidatingRepositoryEventListener(ValidatingRepositoryEventListener validatingListener) {
validatingListener.addValidator("beforeCreate", validator);
validatingListener.addValidator("beforeSave", validator);
}
#Override
public void configureJacksonObjectMapper(ObjectMapper objectMapper) {
objectMapper.setHandlerInstantiator(handlerInstantiator);
}
}
#Component
public class RestResourceURLSerializer extends JsonDeserializer<Long> {
#Autowired
private MyConfig config;
#Override
public Long deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
ServiceConfig serviceConfig = config.getServices().get("identity");
URI serviceUri = serviceConfig.getExternalUrl();
String servicePath = serviceUri.getPath();
URL givenUrl = p.readValueAs(URL.class);
String givenPath = givenUrl.getPath();
if (servicePath.equals(givenPath)) {
return Long.parseLong(givenPath.substring(givenPath.lastIndexOf('/') + 1));
}
return null;
}
}
I keep getting a NullPointerException POSTing something to the API endpoint that is deserialized with the JsonDeserializer above.
I was able to solve a similar problem by marking my deserializer constructor accept a parameter (and therefore removing the empty constructor) and marking constructor as #Autowired.
public class MyDeserializer extends JsonDeserializer<MyEntity> {
private final MyBean bean;
// no default constructor
#Autowired
public MyDeserializer(MyBean bean){
this.bean = bean
}
...
}
#JsonDeserialize(using = MyDeserializer.class)
public class MyEntity{...}
My entity is marked with annotation #JsonDeserialize so I don't have to explicitly register it with ObjectMapper.
I am using Alfresco Process Services and have created a created a spring boot project for custom logic like TaskListeners and Delegations. I am creating the jar file from this maven project and copying it into webapps/activiti-app/WEB-INF/lib folder.
I have a simple TaskListener as below which is getting called on Task start. But the #Autowired variables are always null.
package com.activiti.extension.bean;
#Component("myTaskListener")
public class MyTaskListener implements TaskListener {
#Autowired
UserService userService;
#Override
public void notify(DelegateTask task) {
logger.info("userService: " +userService); // Always prints null
}
Finally I was able to make it work. I was putting the task listener in the class field of the Task properties with full package name. Now I am putting Delegate expression like ${myTaskListener} and it worked...
Thank you all for your time and help
This is because your your MyTaskListener is annotated as #Component or at least being ignored by spring during init. for auto-wiring capabilities spring requires this annotation (or similar to this) under the provided #ComponentScan packages to consider the class as a bean otherwise it will take as a normal java class and hence the #autowired is of no use in your case.
This below code is worked for me
#Component
public class MyTaskListener implements TaskListener {
public static UserService getUserServiceObject() {
return SpringApplicationContextHolder.getApplicationContext().getBean(UserService.class);
}
#Override
public void notify(DelegateTask delegateTask) {
//UserService Object, It is not null now
getUserServiceObject();
}
}
#Component
public class SpringApplicationContextHolder implements ApplicationContextAware {
private static ApplicationContext applicationContext = null;
public static ApplicationContext getApplicationContext() {
return applicationContext;
}
#Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
}
There is also one more way to get to your custom service "UserService" using Alfresco Spring Application context.
First access ServiceRegistry (registry used for accessing Alfresco Services but also any other custom service):
ServiceRegistry serviceRegistry = (ServiceRegistry) Context.getProcessEngineConfiguration().getBeans().get(ActivitiConstants.SERVICE_REGISTRY_BEAN_KEY);
Then get custom service UserService:
QName qname = QName.createQName("UserService");
UserService userService = (UserService) serviceRegistry.getService(qname);
I use spring to inject DemoService has always been null, there is no problem with the filter inject of servlet, in the class of extends TurboFilter, how can I get the DemoService object?
https://stackoverflow.com/questions/30662641/inject-spring-bean-into-custom-logback-filter
I have tried the answer to this connection and did not solve the problem of inject.
public class ErrorLogTurboFilter extends TurboFilter {
#Autowired
private DemoService demoService;
#Override
public FilterReply decide(Marker marker, Logger logger, Level level, String s, Object[] objects, Throwable throwable) {
// todo
return FilterReply.NEUTRAL;
}
}
Problem: Logback starts up before the Spring context. Therefore you need to lazy initialize the Filter with the to be injected bean. Apart from that the Filter will not be called as a Spring bean, but as a Turbofilter, that does not know any injections and so on.
What you could try is define that Filter as a Spring bean in your context, that contains the DemoService. Inject the bean via a Setter for the service, but declare the field static, so you are able to access it from the logging context.
Now during the execution you need to check if the static field is already initialized, if so you can use it without a problem.
You are not trying the answer you are quoting, because your extended filter "ErrorLogTurboFilter" does not have a "#Named("errorLogTurboFilter")" which is the standard annotation to make your filter a spring bean.
see : What is javax.inject.Named annotation supposed to be used for?
#markusw According to your prompt, this is my solution,and thank you.
#Configuration
public class WebConfig {
#Bean
public DemoService demoService() {
return new DemoService();
}
}
public class ErrorLogTurboFilter extends TurboFilter {
private ApplicationContext ctx = new AnnotationConfigApplicationContext(WebConfig.class);
private DemoService demoService = ctx.getBean(DemoService.class);
#Override
public FilterReply decide(Marker marker, Logger logger, Level level, String s, Object[] objects, Throwable throwable) {
// todo
return FilterReply.NEUTRAL;
}
}
This is an Spring MVC project with Hibernate.
I'm, trying to make a Logger class that, is responsible for inputting logs into database.
Other classes just call proper methods with some attributes and this class should do all magic.
By nature it should be a class with static methods, but that causes problems with autowiring dao object.
public class StatisticLogger {
#Autowired
static Dao dao;
public static void AddLoginEvent(LogStatisticBean user){
//TODO code it god damn it
}
public static void AddDocumentEvent(LogStatisticBean user, Document document, DocumentActionFlags actionPerformed){
//TODO code it god damn it
}
public static void addErrorLog(Exception e, String page, HashMap<String, Object> parameters){
ExceptionLogBean elb=new ExceptionLogBean();
elb.setStuntDescription(e);
elb.setSourcePage(page);
elb.setParameters(parameters);
if(dao!=null){ //BUT DAO IS NULL
dao.saveOrUpdateEntity(elb);
}
}
How to make it right? What should I do not to make dao object null?
I know that I could pass it as a method parameter, but that isn't very good.
I'm guessing that autowired can't work on static objects, because they are created to early to autowiring mechanism isn't created yet.
You can't #Autowired a static field. But there is a tricky skill to deal with this:
#Component
public class StatisticLogger {
private static Dao dao;
#Autowired
private Dao dao0;
#PostConstruct
private void initStaticDao () {
dao = this.dao0;
}
}
In one word, #Autowired a instance field, and assign the value to the static filed when your object is constructed. BTW, the StatisticLogger object must be managed by Spring as well.
Classical autowiring probably won't work, because a static class is not a Bean and hence can't be managed by Spring. There are ways around this, for example by using the factory-method aproach in XML, or by loading the beans from a Spring context in a static initializer block, but what I'd suggest is to change your design:
Don't use static methods, use services that you inject where you need them. If you use Spring, you might as well use it correctly. Dependency Injection is an Object Oriented technique, and it only makes sense if you actually embrace OOP.
I know this is an old question but just wanted to share what I did,
the solution by #Weibo Li is ok but the problem it raises Sonar Critical alert about assigning non static variable to a static variable
the way i resolved it with no sonar alerts is the following
I change the StatisticLogger to singlton class (no longer static)
like this
public class StatisticLogger {
private static StatisticLogger instance = null;
private Dao dao;
public static StatisticLogger getInstance() {
if (instance == null) {
instance = new StatisticLogger();
}
return instance;
}
protected StatisticLogger() {
}
public void setDao(Dao dao) {
this.dao = dao;
}
public void AddLoginEvent(LogStatisticBean user){
//TODO code it god damn it
}
public void AddDocumentEvent(LogStatisticBean user, Document document, DocumentActionFlags actionPerformed){
//TODO code it god damn it
}
public void addErrorLog(Exception e, String page, HashMap<String, Object> parameters){
ExceptionLogBean elb=new ExceptionLogBean();
elb.setStuntDescription(e);
elb.setSourcePage(page);
elb.setParameters(parameters);
if(dao!=null){
dao.saveOrUpdateEntity(elb);
}
}
I created a service(or Component) that autowire the service that i want and set it in the singlton class
This is safe since in spring it will initialize all the managed beans before doing anything else and that mean the PostConstruct method below is always called before anything can access the StatisticLogger
something like this
#Component
public class DaoSetterService {
#Autowired
private Dao dao0;
#PostConstruct
private void setDaoValue () {
StatisticLogger.getInstance().setDao(dao0);
}
}
Instead of using StatisticLogger as static class I just use it as StatisticLogger.getInstance() and i can access all the methods inside it
You can pass the DAO to StatisticLogger from where you call it.
public static void AddLoginEvent(LogStatisticBean user, DAO dao){
dao.callMethod();
}
It might be too late to put an answer to this question, especially when a question is already having an accepted answer. But it might help others in case they face the same issue.
inside the StatisticLogger class create an instance of the Dao service.
public static Dao daoService = new Dao();
then, auto-wire the service instance through the constructor of the StatisticLogger class.
#Autowired
public functionName(Dao daoService0) {
this.daoService = daoService0;
}
//use this service as usual in static class
daoService.fun();
I think this is the simplest solution for the problem.
Is possible to get the proxy of a given object in Spring? I need to call a function of a subclass. But, obviously, when I do a direct call, the aspects aren't applied. Here's an example:
public class Parent {
public doSomething() {
Parent proxyOfMe = Spring.getProxyOfMe(this); // (please)
Method method = this.class.getMethod("sayHello");
method.invoke(proxyOfMe);
}
}
public class Child extends Parent {
#Secured("president")
public void sayHello() {
System.out.println("Hello Mr. President");
}
}
I've found a way of achieving this. It works, but I think is not very elegant:
public class Parent implements BeanNameAware {
#Autowired private ApplicationContext applicationContext;
private String beanName; // Getter
public doSomething() {
Parent proxyOfMe = applicationContext.getBean(beanName, Parent.class);
Method method = this.class.getMethod("sayHello");
method.invoke(proxyOfMe);
}
}
This hack is extremely awkward, please consider refactoring your code or using AspectJ weaving. You may feel warned, here is the solution
AopContext.currentProxy()
JavaDoc. I blogged about it here and here.
AopContext.currentProxy() as suggested by Tomasz will work. A more generic solution, that will work outside of the proxied class is to cast the object to org.springframework.aop.framework.Advised and get .getTargetSource().getTarget()
The former (getting the real object from the proxied object) is something that you should not really need. On the other hand getting the target proxy might be useful in some utility class that inspects existing beans in order to add some feature.
You can use a bean post-processor to set a reference to the proxy on the target bean. It moves the Spring-specifics from your beans to a single class.
Post-Processor
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
public class SelfReferencingBeanPostProcessor implements BeanPostProcessor {
#Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
return bean;
}
#Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
if (bean instanceof SelfReferencingBean) {
((SelfReferencingBean) bean).setProxy(bean);
}
return bean;
}
}
Context
Register the post-processor in applicationContext.xml.
<bean id="srbpp" class="SelfReferencingBeanPostProcessor"/>
Beans
Each bean must implement SelfReferencingBean to tell the post-processor that it needs a reference to the proxy.
public interface SelfReferencingBean {
void setProxy(Object proxy) ;
}
Now implement setProxy in each bean that needs to call itself through its proxy.
public class MyBean implements SelfReferencingBean {
MyBean proxy;
#Override
public void setProxy(Object proxy) {
this.proxy = (MyBean) proxy;
}
}
You could put this last bit of code into a bean base class if you don't mind casting proxy to bean's type when calling methods directly on it. Since you're going through Method.invoke you wouldn't even need the cast.
With a little work I bet this could be converted to an annotation processor a la #Autowired. Come to think of it, I don't recall if I even tried adding a self-reference using #Autowired itself.
public class MyBean implements SelfReferencingBean {
#Autowired MyBean proxy;
}