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To call Strava API from SpringBoot application

I'm trying to develop my first java Spring Bboot app that calls Strava API and gets my activities for the given period of time.
I've registered my app on Strava's website and got client_id and client secret.
I've generated spring-swagger-codegen-api-client and awtowired the client to the app.
#Configuration
public class StravaIntegrationConfiguration {
#Bean
public ActivitiesApi stravaApi(){
return new ActivitiesApi(apiClient());
}
#Bean
public ApiClient apiClient(){
return new ApiClient();
}
}
Then I use this bean in AdapterClass
public class Adapter {
#Autowired
private static ActivitiesApi activitiesApi;
public static void getActivities(Integer before, Integer after, Integer page, Integer perPage) {
final List<SummaryActivity> loggedInAthleteActivities = activitiesApi.getLoggedInAthleteActivities(before, after, page, perPage);
System.out.println("ВСЕГО АКТИВНОСТЕЙ"+ loggedInAthleteActivities.size());
}
}
#SpringBootApplication
#Import(StravaIntegrationConfiguration.class)
public class App {
public static void main(String[] args) throws SQLException {
SpringApplication.run(App.class);
Adapter.getActivities(1636130496, 1635529296, 1, 30);
}
}
When I run this code I get NPE, because activitiesApi is null.
What is the problem? Please kindly advise.
Does it concern authentication? Could you advise also any code sample on how to make Strava authentication in my app?

It has nothing to do with Strava authentication. It is related to Spring context and Spring Beans and how to inject them. As already mentioned you can't autowire Spring-managed beans in static fields (it makes no sense actually). Having said that you need to fix that first:
#Component
public class Adapter {
#Autowired
private ActivitiesApi activitiesApi;
public void getActivities(Integer before, Integer after, Integer page, Integer perPage) {
final List<SummaryActivity> loggedInAthleteActivities = activitiesApi.getLoggedInAthleteActivities(before, after, page, perPage);
System.out.println("ВСЕГО АКТИВНОСТЕЙ"+ loggedInAthleteActivities.size());
}
}
Also, note that the method changed from a static one to an instance one and that the annotation #Component was added to the class. The reason is that a Spring-managed bean can only be injected into other Spring-managed beans.
Additionally, it seems to me that you are trying to do something after the Spring context has been initialized. One possible way to do this is creating a bean that implements the ApplicationListener interface:
#Component
public class StartupApplicationListener implements ApplicationListener<ContextRefreshedEvent> {
#Autowired
private Adapter adapter;
#Override
public void onApplicationEvent(ContextRefreshedEvent event) {
adapter.getActivities(1636130496, 1635529296, 1, 30);
}
}
This means that you can and you should remove the line Adapter.getActivities(1636130496, 1635529296, 1, 30); from your main class:
#SpringBootApplication
#Import(StravaIntegrationConfiguration.class)
public class App {
public static void main(String[] args) throws SQLException {
SpringApplication.run(App.class);
}
}
Finally, and as a side note, please consider using constructor injection instead of field injection. It has a couple of advantages over field injection: making the class easier to unit test, allowing the objects to be immutable, explicitly definition of which dependencies are mandatory, etc... (you can read more at https://reflectoring.io/constructor-injection/).

spring dependency injection is not working in a class annotated with #WebListener

I tried constructor based Dependency injection in TestAppListener class which implements ServletContextListener.
I got this error
Exception sending context initialized event to listener instance of class [com.example.listener.TestAppListener].
I searched stack overflow but I couldn't find any solution for this scenario. Please any one help me in sort out this. I placed Implementation classes in META-INF.services folder also. My understanding is there is some problem in constructor dependency injection but this way of DI is need for my situation, because in real time I want to create datasource connection inside startup method.
Find all my classes below which i'm using,
#WebListener
public class TestAppListener implements ServletContextListener {
private static TestDao dao;
public TestAppListener(TestDao dao){
this.dao = dao;
}
public TestAppListener(){}
#Override
public void contextInitialized(ServletContextEvent sce) {
dao = ServiceLoader.load(TestDao.class).iterator().next();
dao.startUp();
System.out.println("Context initialized method called");
}
#Override
public void contextDestroyed(ServletContextEvent sce) {
System.out.println("Context destroyed method called");
dao.shutDown();
}
}
public interface TestDao {
void startUp();
void shutDown();
}
public class TestDaoImpl implements TestDao {
#Override
public void startUp() {
System.out.println("Database is initialized");
}
#Override
public void shutDown() {
System.out.println("Database is initialized");
}
}
#Configuration
public class SpringConfig {
public SpringConfig() {
}
#Bean
public ServletListenerRegistrationBean<ServletContextListener> listenerRegistrationBean() {
ServletListenerRegistrationBean<ServletContextListener> bean = new ServletListenerRegistrationBean<>();
bean.setListener(new TestAppListener());
return bean;
}
}

The Servlet #WebListeners are handled by Servlet containers(tomcat/Jetty) when the container is starting. So they know nothing about Spring.
For more details, see discussion in this issue.
A workaround solution is replace the #WebListener with Spring's #Component, thus you can inject Spring beans(declare your Dao as spring beans) into the listeners directly.
BTW, you have to add #ServletComponentScan on your Spring Boot application class to activate it.
I created an example project to demo #WebServlet, #WebFilter and #WebListener.

Change private static TestDao dao to private final TestDao dao. Spring doesn't allow statics to be used as targets for injection. Also, your TestDaoImpl class needs to be a component or a bean defined in a Spring configuration file.

Calling method depending on environment in spring boot

I have two methods, implementations differ depending on environment (dev / prod).
Is it a good idea to use a variable from application.properties? For example:
production-mode:true
and use it:
#Value("${production-mode}")
private boolean isProd;
...
if (isProd) {
methodForProduction();
} else {
methodForDevelopment();
}
Do you have any suggestions or could you point me in the direction of some useful resources?

Spring boot comes with a profile management system that allow you to active or swap functionnality and behaviour depending on those.
Here is a link to the official documentation.
What you could do is create an interface and 2 implementations as such :
public interface MyClass {
void myMethod();
}
public class MyClassForDevelopment implements MyClass {
#Override
public void myMethod() { // your code for developement }
}
public class MyClassForProduction implements MyClass {
#Override
public void myMethod() { // your code for production }
}
And use the configuration of Spring boot as such :
#Configuration
public class MyConfiguration {
#Bean
#Profile("dev")
public MyClass myClassDev() { return new MyClassForDevelopment(); }
#Bean
#Profile("prod")
public MyClass myClassProd() { return new MyClassForProduction(); }
}

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;
}
}

How to write tag in my spring project?

I want to write my tag (extends TagSupport) in my spring framework. In my tag class, will use some service which should auto inject by spring. But I always get null, seems spring can't inject service instance in my tag class.
The code is like the following:
public class FetchTagNameTag extends TagSupport {
#Autowired
private TaskService taskService;
...
taskService is always null.
How can I resolve this?
Thanks.

Have a try by utilizing RequestContextAwareTag. It will offer you methods to obtain RequestContext and then WebApplicaitonContext. Have a look at here.

JSP tag objects are not managed by Spring, they are managed by the servlet container. As a result, you cannot autowire stuff into your tags.
If you need to get hold of beans from the spring appcontext, then your Spring MVC controller needs to set the bean as a request attribute (using request.setAttribute()), so that the tag object can get hold of it.

Annotate your Tag-Implementation with #Configurable and add <context:component-scan base-package="your.webapp"> to your Spring-Configuration.

Check out these spring packages in the spring reference docs and in the spring source:
org.springframework.web.servlet.tags
org.springframework.web.servlet.tags.form
If nothing else, those will show you how the spring developers wrote the spring tags.

What you could do is create a static method like this:
public static void autowireAllFor(Object target) {
AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
bpp.setBeanFactory(...yourBeanFactory...);
bpp.processInjection(target);
}
and then for your tag you could do
public class YourTag extends TagSupport {
#Autowired
private SomeBean someBean;
public YourTag() {
YourHelperClass.autowireAllFor(this);
}
}
The obvious disadvantage of this approach is that you have to do this for every constructor, but as TagSupport only has one, it should not be a problem. You can go even one step further and create a helper superclass which always guarantees autowiring:
public class SpringTagSupport extends TagSupport {
public SpringTagSupport() {
super();
YourHelperClass.autowireAllFor(this);
}
}
The rest is as easy as extending your classes from SpringTagSupport.

First I write this:
public abstract class SpringSuportedTag extends SimpleTagSupport{
protected WebApplicationContext _applicationContext;
protected WebApplicationContext getSpringContext(){
PageContext pageContext = (PageContext) getJspContext();
if(_applicationContext==null){
_applicationContext = RequestContextUtils.getWebApplicationContext(
pageContext.getRequest(),
pageContext.getServletContext()
);
initCustomBeans();
}
return _applicationContext;
}
protected abstract void initCustomBeans();
/**
* Deprecated for inserting extra logic. Use {#link #doTagWithSpring()} instead.
*/
#Override
#Deprecated
public void doTag() throws JspException, IOException {
getSpringContext();
doTagWithSpring();
}
abstract void doTagWithSpring() throws JspException, IOException;
}
And usage:
public class SlotTag extends SpringSuportedTag {
// #Resource(name="userDetailHolder")
// not work here
UserDetailHolder userDetail;
private String slotname;
public String getSlotname() {
return slotname;
}
public void setSlotname(String slotname) {
this.slotname = slotname;
}
#Override
void doTagWithSpring() throws JspException, IOException {
PageContext pageContext = (PageContext) getJspContext();
String userDetailCode = pageContext.getAttribute(InitWidgetUserTag.KAY_USERDETAIL, PageContext.PAGE_SCOPE).toString();
userDetail.init(userDetailCode);
String pageID = pageContext.getAttribute(InitWidgetUserTag.KAY_PAGEID, PageContext.PAGE_SCOPE).toString();
getJspContext().getOut().println("<b>slot for user:"+userDetail.getUserId()+"</b>");
}
#Override
protected void initCustomBeans() {
userDetail = (UserDetailHolder) getSpringContext().getBean("userDetailHolder");
}
}
It's work.
But than i found this:
Spring supported Tag Libraries. Truth in my progect I still use own solution.

Use :-
import org.springframework.web.servlet.tags.RequestContextAwareTag;
public class FetchTagNameTag extends RequestContextAwareTag {
// #Autowired
// private TaskService taskService;
#Override
protected int doStartTagInternal() throws Exception {
TaskService taskService= getRequestContext().getWebApplicationContext().getBean(TaskService.class);
return 0;
}