I am using quarkus 1.2.0.
General:
The client browser is asking for data from the server. Server (Quarkus app) is receiving the time in utc from the client. (ok) Now the server should compare the data from the database with the clients browser-time and should return every data from the database, which is after the clients-time.
I have postgres as database. Every time when I save new data or modifie data into the database I save the data with the UTC time.
I enforce this with <property name="hibernate.jdbc.time_zone" value="UTC"/> in the persistence.xml.
I have checked this, the data is save in utc time in the postgres database.
The problem:
Although the data is save in utc in the database, when quarkus fetches the data from the database, it transfers the data to the local timezone (GMT +0100).
Now I have the problem that the server is comparing the data converted to (GMT) with the clients time (UTC).
How can I force quarkus to use UTC timezone?
Have you tried to pass -Duser.timezone=UTC when executing your jar?
A Quarkus app is just a standard Java app.
Another option would be to set it up in your application directly by creating a CDI bean observing the startup event:
#Singleton
public class TimezoneSettings {
public void setTimezone(#Observes StartupEvent startupEvent) {
System.setProperty("user.timezone", "UTC");
}
}
I'm just not entirely sure it will be early enough for your application though. You will have to try it.
If using hibernate: https://quarkus.io/guides/all-config
quarkus.hibernate-orm.jdbc.timezone=UTC
This solution works in quarkus dev mode as well:
import javax.ws.rs.core.Application;
import java.util.TimeZone;
public class YourApplication extends Application {
public YourApplication() {
super();
TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
}
}
Related
This is the code where I am using the GMT timezone. I am saving the data at 2:00 pm but it is showing 8:30 am in database.
type: com.zaxxer.hikari.HikariDataSource
url: jdbc:mysql://localhost:3306/mydatabase?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&useSSL=false&useLegacyDatetimeCode=false&serverTimezone=GMT&connectionTimeZone=GMT&createDatabaseIfNotExist=true
username: root
password: Password
Add this method to your springboot application main class.
/*setting timezone to GMT*/
#PostConstruct
public void init(){
TimeZone.setDefault(TimeZone.getTimeZone("GMT"));
}
Also add the below property in your application.properties file
spring.jpa.properties.hibernate.jdbc.time_zone=GMT
this property will instruct Hibernate to use the provided time zone when reading and writing timestamp column values.
Is there any way to refresh springboot configuration as soon as we change .properties file?
I came across spring-cloud-config and many articles/blogs suggested to use this for a distributed environment. I have many deployments of my springboot application but they are not related or dependent on one another. I also looked at few solutions where they suggested providing rest endpoints to refresh configs manually without restarting application. But I want to refresh configuration dynamically whenever I change .properties file without manual intervention.
Any guide/suggestion is much appreciated.
Can you just use the Spring Cloud Config "Server" and have it signal to your Spring Cloud client that the properties file changed. See this example:
https://spring.io/guides/gs/centralized-configuration/
Under the covers, it is doing a poll of the underlying resource and then broadcasts it to your client:
#Scheduled(fixedRateString = "${spring.cloud.config.server.monitor.fixedDelay:5000}")
public void poll() {
for (File file : filesFromEvents()) {
this.endpoint.notifyByPath(new HttpHeaders(), Collections
.<String, Object>singletonMap("path", file.getAbsolutePath()));
}
}
If you don't want to use the config server, in your own code, you could use a similar scheduled annotation and monitor your properties file:
#Component
public class MyRefresher {
#Autowired
private ContextRefresher contextRefresher;
#Scheduled(fixedDelay=5000)
public void myRefresher() {
// Code here could potentially look at the properties file
// to see if it changed, and conditionally call the next line...
contextRefresher.refresh();
}
}
We have a spring application where redis cache has been implemented along with the database MySQL. Here we are using redis cache to store the temporary values for the server validations instead of hitting the database every time, hence hitting the database calls every time gets reduces system performance.
Now i explain my problem while hitting the spring boot action endpoints,
if suddenly my redis cache server stops, we would like to know how to get the notification that my redis cache server is down. So we need solution / example java application to get the notification using redis cache listener context or anything like that.
Redis doesn't work that way. In fact, no remote service will notify your application that it's down. Usually, it's the other way round: If the service you're consuming is accessed with a more or less sophisticated client, you might take advantage of the client's features.
Asynchronous clients that run I/O, or monitoring threads can help here. More specific, it depends on the client you're using with Spring Boot and Redis. Jedis is a plain client that reacts on a request basis. Lettuce allows you to register a RedisConnectionStateListener that is called on specific connection events, such as connected/disconnected:
RedisClient redisClient = …;
redisClient.addListener(new RedisConnectionStateListener() {
#Override
public void onRedisConnected(RedisChannelHandler<?, ?> redisChannelHandler) {
}
#Override
public void onRedisDisconnected(RedisChannelHandler<?, ?> redisChannelHandler) {
}
#Override
public void onRedisExceptionCaught(RedisChannelHandler<?, ?> redisChannelHandler, Throwable throwable) {
}
});
When using Spring Data Redis, retrieving the RedisClient from LettuceConnectionFactory might be a bit tricky as it is a private field. Hence it requires reflection.
I am trying to use flyway for DB migrations and Spring boot's flyway support for auto-upgrading DB upon application start-up and subsequently this database will be used by my JPA layer
However this requires that schema be present in the DB so that primary datasource initialization is successful. What are the options available to run a SQL script that will create the required schema before flyway migrations happen.
Note that If I use flyway gradle plugin (and give the URL as jdbc:mysql://localhost/mysql. It does create the schema for me. Am wondering if I could make this happen from Java code on application startup.
Flyway does not support full installation when schema is empty, just migration-by-migration execution.
You could though add schema/user creation scripts in the first migration, though then your migration scripts need to be executed with sysdba/root/admin user and you need to set current schema at the beginning of each migration.
If using Flyway, the least problematic way is to install schema for the first time manually and do a baseline Flyway task (also manually). Then you are ready for next migrations to be done automatically.
Although Flyway is a great tool for database migrations it does not cover this particular use case well (installing schema for the first time).
"Am wondering if I could make this happen from Java code on application startup."
The simple answer is yes as Flyway supports programmatic configuration from with java applications. The starting point in the flyway documentation can be found here
https://flywaydb.org/documentation/api/
flyway works with a standard JDBC DataSource and so you can code the database creation process in Java and then have flyway handle the schema management. In many environment you are likely to require 2 steps anyway as the database/schema creation will need admin rights to the database, while the ongoing schema management will need an account with reduced access rights.
what you need is to implement the interface FlywayCallback
in order to kick start the migration manually from you code you can use the migrate() method on the flyway class
tracking the migration process can be done through the MigrationInfoService() method of the flyway class
Unfortunately if your app has a single datasource that expects the schema to exist, Flyway will not be able to use that datasource to create the scheme. You must create another datasource that is not bound to the schema and use the unbounded datasource by way of a FlywayMigrationStrategy.
In your properties file:
spring:
datasource:
url: jdbc:mysql://localhost:3306/myschema
bootstrapDatasource:
url: jdbc:mysql://localhost:3306
In your config file:
#Bean
#Primary
#ConfigurationProperties("spring.datasource")
public DataSourceProperties primaryDataSourceProperties() {
return new DataSourceProperties();
}
#Bean
#Primary
#ConfigurationProperties("spring.datasource")
public DataSource primaryDataSource() {
return primaryDataSourceProperties().initializeDataSourceBuilder().build();
}
#Bean
#ConfigurationProperties("spring.bootstrapDatasource")
public DataSource bootstrapDataSource() {
return DataSourceBuilder.create().build();
}
And in your FlywayMigrationStrategy file:
#Inject
#Qualifier("bootstrapDataSource")
public void setBootstrapDataSource(DataSource bootstrapDataSource) {
this.bootstrapDataSource = bootstrapDataSource;
}
#Override
public void migrate(Flyway flyway) {
flyway.setDataSource(bootstrapDataSource);
...
flyway.migrate()
}
I am looking for a way to auto insert a default admin account, using JPA, when my spring mvc application is deployed.
My database is generated based on the Entities.
I want to kick off something that will insert a default admin user, assign roles, every time the application is deployed.
It depends on which implementation of JPA you use.
If you use Hibernate you can add import.sql file (that contains records to load) to the class path. More info here.
As a workaround you can also use dbunit tool.
I would recommend having a migration utility that will keep your database in synch with your codebase - these are typically DDL's, but again the queries to insert default admin user, assign roles etc can also be part of this migration utility. There are very good one's available - Flyway is one that I have used, Liquibase is another one.
There is a very good comparison of the different migration utilities on the Flyway homepage also that you can look at.
i use CommandLineRunner interface.
#Component
public class CommandLineAppStartupRunner implements CommandLineRunner {
#Autowired
UserRepository userRepository;
#Override
public void run(String...args) throws Exception {
User admin = new user(firstName);
userRepository.save(admin);
}
}
before the app starts this class will be executed.
you can find other ways here : Guide To Running Logic on Startup in Spring