I want to cache the following getMessagesList method. I want to call one time When user log into the system. Therefor I think caching is the best solution for that. And I need to remove when user log out. How I can do this.
public List<String> getMessagesList(String username)
{ // return messages list in DB by username}
My project was create using Maven 4.0 and Spring MVC. spring version 5.3
Assuming you use Spring Security as part of your app, it should be managing your session, and every time you log out, it will create a new session. Unless you had posted this code, I'm not going to be able to help you there. However, assuming you can log in/out, this should be covered already.
As for the cacheing, in general, this sounds like a Database Caching need, which is something that you would use Spring Boot Caching on.
To use this in Spring Boot, you would add the following dependency to maven (or the equivalent in Gradle, etc):
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
Adjust your application to allow using Cacheing, which can be done by adding the annotation #EnableCaching to your Spring Boot application
#SpringBootApplication
#EnableCaching
public class MyApplication {
...
}
Create a Java Service Object, called something like MessagesService.class:
#CacheConfig(cacheNames={"Messages"})
public class MessagesService {
#Cacheable(value="cacheMessages")
List<String> getMessages() {
//access the database to load data here
...
}
...
}
Related
I am developing a module with spring boot in my backend where i need to use Redis through GCP Memory Store. I have been searching in forum and even the "oficial documentation" about memory store but i cannot understand how to connect to memory store with my spring boot app.
I found a google code lab but they use a Compute Engine VM to install spring boot and then save and retrieve information from memory store. So i tried to do it like that in my local spring boot but it didnt work because throws an error saying:
Unable to connect to Redis; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to 10.1.3.4
the codelab i mentioned earlier says that you only have to add this line to your application.properties:
spring.redis.host=10.1.3.4
as well as the annotation #EnableCaching in the main class and #Cachable annotation in the controller method where you try to do something with redis.
the method looks like this:
#RequestMapping("/hello/{name}")
#Cacheable("hello")
public String hello(#PathVariable String name) throws InterruptedException {
Thread.sleep(5000);
return "Hello " + name;
}
i dont know what else to do. Notice that i am new on this topic of redis and memory store.
Anyone can give me some guidance on this please?
thanks in advance
codelab url: https://codelabs.developers.google.com/codelabs/cloud-spring-cache-memorystore#0
See this documentation on how to setup Memorystore Redis instance.
Included in the documentation is how you can connect and test your Memorystore instance from different computing environments.
There's also a step by step guide on how SpringBoot can use Redis to cache with annonations.
Add the Spring Data Redis starter in your pom.xml if you're using Maven for your project setup.
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
Add this configuration in your application.properties file:
spring.redis.host=<MEMORYSTORE_REDIS_IP>
# Configure default TTL, e.g., 10 minutes
spring.cache.redis.time-to-live=600000
Turn on caching capability explicitly with the #EnableCaching annotation:
#SpringBootApplication
#EnableCaching
class DemoApplication {
...
}
Once you configured the Spring Boot with Redis and enabled caching, you can use the #Cacheable annotation to cache return values.
#Service
class OrderService {
private final OrderRepository orderRepository;
public OrderService(OrderRepository orderRepository) {
this.orderRepository = orderRepository;
}
#Cacheable("order")
public Order getOrder(Long id) {
orderRepository.findById(id);
}
}
I read everywhere #RefreshScope for cloud bus applications work with RabbitMQ and Kafka. But in my case, I am using AWS Parameter store. I want all my client instances to be refreshed automatically without rebuilding servers on AWS Console.
I created AWS Eventbridge from Paramstore to notify Kinesis Stream but I am not able to figure out how can it notify all my client nodes instead of load balancer refresh to only one node(instance).
Thank you for responding in advance.
I've never worked with AWS Eventbridge / Kinesis, however:
#RefreshScope is something that belongs to spring cloud and not not AWS.
More precisely, beans defined with this scope will be re-loaded by spring without reloading the whole application context "dynamically" when configuration changes in spring boot cloud configuration service. Usually this means that you don't have to restart the application.
Now, spring boot microservice should be deployed with actuator that exposes refresh endpoint. Calling this endpoint manually will cause all the #RefreshScope beans to reload.
Here is the source code of the RefreshEndpoint:
#Endpoint(id = "refresh")
public class RefreshEndpoint {
private ContextRefresher contextRefresher;
public RefreshEndpoint(ContextRefresher contextRefresher) {
this.contextRefresher = contextRefresher;
}
#WriteOperation
public Collection<String> refresh() {
Set<String> keys = this.contextRefresher.refresh();
return keys;
}
}
As you see, its merely invokes contextRefresher.refresh(), ContextRefresher is a bean that you can inject in your custom code that will listen to the changes coming from AWS Parameter store (it should somehow invoke it directly or maybe send some message that you could consume or something).
If you're using spring-cloud-bus (disclaimer, I've never worked with it) it exposes the bus-refresh endpoint as well (pretty similar mechanism to what I've described), read spring-cloud-bus documentation for more details.
Thank you Team for sharing info.
Here is what I did to make it work. Added these two libraries to my project
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-stream-binder-kinesis</artifactId>
<version>1.1.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-bus</artifactId>
</dependency>
And added these two entries into bootstrap.properties
cloud.aws.region.static=us-east-1
cloud.aws.stack.auto = false
And refreshing using this endpoint (/bus-refresh)
The OpenApi documentation says that it supports micrometer. How does the integration works? I could not find anything except this little documentation.
I have a FeignClient in a spring boot application
#FeignClient(name = "SomeService", url = "xxx", configuration = FeignConfiguration.class)
public interface SomeService {
#GET
#Path("/something")
Something getSomething();
}
with the configuration
public class FeignConfiguration {
#Bean
public Capability capability() {
return new MicrometerCapability();
}
}
and the micrometer integration as a dependency
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-micrometer</artifactId>
<version>10.12</version>
</dependency>
The code makes a call but I could not find any new metrics via the actuator overview, expecting some general information about my HTTP requests. What part is missing?
Update
I added the support for this to spring-cloud-openfeign. After the next release (2020.0.2), if micrometer is set-up, the only thing you need to do is putting feign-micrometer onto your classpath.
Old answer
I'm not sure if you do but I recommend to use spring-cloud-openfeign which autoconfigures Feign components for you. Unfortunately, it seems it does not autoconfigure Capability (that's one reason why your solution does not work) so you need to do it manually, please see the docs how to do it.
I was able to make this work combining the examples in the OpenFeign and Spring Cloud OpenFeign docs:
#Import(FeignClientsConfiguration.class)
class FooController {
private final FooClient fooClient;
public FooController(Decoder decoder, Encoder encoder, Contract contract, MeterRegistry meterRegistry) {
this.fooClient = Feign.builder()
.encoder(encoder)
.decoder(decoder)
.contract(contract)
.addCapability(new MicrometerCapability(meterRegistry))
.target(FooClient.class, "https://PROD-SVC");
}
}
What I did:
Used spring-cloud-openfeign
Added feign-micrometer (see feign-bom)
Created the client in the way you can see above
Importing FeignClientsConfiguration and passing MeterRegistry to MicrometerCapability are vital
After these, and calling the client, I had new metrics:
feign.Client
feign.Feign
feign.codec.Decoder
feign.codec.Decoder.response_size
When we use 'KeycloakSpringBootConfigResolver' for reading the keycloak configuration from Spring Boot properties file instead of keycloak.json.
Now there are guidelines to implement a multi-tenant application using keycloak by overriding 'KeycloakConfigResolver' as specified in http://www.keycloak.org/docs/2.3/securing_apps_guide/topics/oidc/java/multi-tenancy.html.
The steps defined here can only be used with keycloak.json.
How can we adapt this to a Spring Boot application such that keycloak properties are read from the Spring Boot properties file and multi-tenancy is achieved.
You can access the keycloak config you secified in your application.yaml (or application.properties) if you inject org.keycloak.representations.adapters.config.AdapterConfig into your component.
#Component
public class MyKeycloakConfigResolver implements KeycloakConfigResolver {
private final AdapterConfig keycloakConfig;
public MyKeycloakConfigResolver(org.keycloak.representations.adapters.config.AdapterConfig keycloakConfig) {
this.keycloakConfig = keycloakConfig;
}
#Override
public KeycloakDeployment resolve(OIDCHttpFacade.Request request) {
// make a defensive copy before changing the config
AdapterConfig currentConfig = new AdapterConfig();
BeanUtils.copyProperties(keycloakConfig, currentConfig);
// changes stuff here for example compute the realm
return KeycloakDeploymentBuilder.build(currentConfig);
}
}
After several trials, the only feasible option for spring boot is to have
Multiple instances of the spring boot application running with different spring 'profiles'.
Each application instance can have its own keycloak properties (as it is under different profiles) including the realm.
The challenge is to have an upgrade path for all instances for version upgrades/bug fixes, but I guess there are multiple strategies already implemented (not part of this discussion)
there is a ticket regarding this problem: https://issues.jboss.org/browse/KEYCLOAK-4139?_sscc=t
Comments for that ticket also talk about possible workarounds intervening in servlet setup of the service used (Tomcat/Undertow/Jetty), which you could try.
Note that the documentation you linked in your first comment is super outdated!
I am using spring boot, and I have two external properties files, so that I can easily change its value.
But I hope spring app will reload the changed value when it is updated, just like reading from files. Since property file is easy enough to meet my need, I hope I don' nessarily need a db or file.
I use two different ways to load property value, code sample will like:
#RestController
public class Prop1Controller{
#Value("${prop1}")
private String prop1;
#RequestMapping(value="/prop1",method = RequestMethod.GET)
public String getProp() {
return prop1;
}
}
#RestController
public class Prop2Controller{
#Autowired
private Environment env;
#RequestMapping(value="/prop2/{sysId}",method = RequestMethod.GET)
public String prop2(#PathVariable String sysId) {
return env.getProperty("prop2."+sysId);
}
}
I will boot my application with
-Dspring.config.location=conf/my.properties
I'm afraid you will need to restart Spring context.
I think the only way to achieve your need is to enable spring-cloud. There is a refresh endpoint /refresh which refreshes the context and beans.
I'm not quite sure if you need a spring-cloud-config-server (its a microservice and very easy to build) where your config is stored(Git or svn). Or if its also useable just by the application.properties file in the application.
Here you can find the doc to the refresh scope and spring cloud.
You should be able to use Spring Cloud for that
Add this as a dependency
compile group: 'org.springframework.cloud', name: 'spring-cloud-starter', version: '1.1.2.RELEASE'
And then use #RefreshScope annotation
A Spring #Bean that is marked as #RefreshScope will get special treatment when there is a configuration change. This addresses the problem of stateful beans that only get their configuration injected when they are initialized. For instance if a DataSource has open connections when the database URL is changed via the Environment, we probably want the holders of those connections to be able to complete what they are doing. Then the next time someone borrows a connection from the pool he gets one with the new URL.
Also relevant if you have Spring Actuator
For a Spring Boot Actuator application there are some additional management endpoints:
POST to
/env to update the Environment and rebind #ConfigurationProperties and log levels
/refresh for re-loading the boot strap context and refreshing the #RefreshScope beans
Spring Cloud Doc
(1) Spring Cloud's RestartEndPoint
You may use the RestartEndPoint: Programatically restart Spring Boot application / Refresh Spring Context
RestartEndPoint is an Actuator EndPoint, bundled with spring-cloud-context.
However, RestartEndPoint will not monitor for file changes, you'll have to handle that yourself.
(2) devtools
I don't know if this is for a production application or not. You may hack devtools a little to do what you want.
Take a look at this other answer I wrote for another question: Force enable spring-boot DevTools when running Jar
Devtools monitors for file changes:
Applications that use spring-boot-devtools will automatically restart
whenever files on the classpath change.
Technically, devtools is built to only work within an IDE. With the hack, it also works when launched from a jar. However, I may not do that for a real production application, you decide if it fits your needs.
I know this is a old thread, but it will help someone in future.
You can use a scheduler to periodically refresh properties.
//MyApplication.java
#EnableScheduling
//application.properties
management.endpoint.refresh.enabled = true
//ContextRefreshConfig.java
#Autowired
private RefreshEndpoint refreshEndpoint;
#Scheduled(fixedDelay = 60000, initialDelay = 10000)
public Collection<String> refreshContext() {
final Collection<String> properties = refreshEndpoint.refresh();
LOGGER.log(Level.INFO, "Refreshed Properties {0}", properties);
return properties;
}
//add spring-cloud-starter to the pom file.
Attribues annotated with #Value is refreshed if the bean is annotated with #RefreshScope.
Configurations annotated with #ConfigurationProperties is refreshed without #RefreshScope.
Hope this will help.
You can follow the ContextRefresher.refresh() code implements.
public synchronized Set<String> refresh() {
Map<String, Object> before = extract(
this.context.getEnvironment().getPropertySources());
addConfigFilesToEnvironment();
Set<String> keys = changes(before,
extract(this.context.getEnvironment().getPropertySources())).keySet();
this.context.publishEvent(new EnvironmentChangeEvent(context, keys));
this.scope.refreshAll();
return keys;
}