Change Spring config connection in runtime - java

I need to change my connection with the Database in runtime. For Example, if parameter requested is BD1, connect on database 1, if BD2, connect in database 2, etc.
I am using spring boot. What is the best way for this.
I have this #Configuration, but not know to say my repository how to use.
#Configuration
public class DataSourceConfiguration {
#Bean(name = "ccteste")
#ConfigurationProperties("spring.ciclocairu.teste.datasource")
#Primary
public DataSource ciclocairuTeste() {
return DataSourceBuilder.create().build();
}
#Bean(name = "ccprod")
#ConfigurationProperties("spring.ciclocairu.prod.datasource")
public DataSource ciclocairuProd() {
return DataSourceBuilder.create().build();
}
#Bean(name = "tmccteste")
#Autowired
#Primary
DataSourceTransactionManager transactionManagerCicloCairuTeste(#Qualifier("ccteste") DataSource datasource) {
DataSourceTransactionManager txm = new DataSourceTransactionManager(datasource);
return txm;
}
#Bean(name = "tmccprod")
#Autowired
#Primary
DataSourceTransactionManager transactionManagerCicloCairuProd(#Qualifier("ccprod") DataSource datasource) {
DataSourceTransactionManager txm = new DataSourceTransactionManager(datasource);
return txm;
}
}

Looks like you are looking for some data source routing. Spring has AbstractRoutingDataSource for run-time detection what data source should be used.
Abstract DataSource implementation that routes getConnection() calls
to one of various target DataSources based on a lookup key.
Also you can set default datasource by setDefaultTargetDataSource method.
It works in such way: you put data sources that you need in a map in AbstractRoutingDataSource at the bean configuration stage, and when you need to use a specific data source you put the key for this source into the context that linked to the router. This ds-key is linked to the current thread.
Here are examples : Dynamic DataSource Routing with Spring and Spring DataSource Routing

Might take a look at my answer at Manage transactions with multiple datasource, entity managers for same application code
or my blog post: Multi-tenant applications using Spring Boot, JPA, Hibernate and Postgres

Related

How to configure #Transactional support to Redis in Springboot?

I am currently working on a project which is using Redis mainly for caching purposes, I am using Oracle as the main database and Spring Data JPA to handle the database layer in my project. I need to know how to use #Transactional annotation support to handle transactions in Redis. I have already referred to lots of tutorials and documentation regarding this scenario. In most of those tutorials, there is always the same set of source codes available. But still, I didn't have a clear idea about the implementation. Because in my application there is already a data source available which I configured through property file. (Oracle database) So I doubt the implementation of the dataSource bean. And I couldn't understand the usage of transactionManager bean too. How should I implement this properly please give a detailed explanation.
Source code which I found on the internet.
#Configuration
#EnableTransactionManagement // 1
public class RedisConfig {
#Bean
public StringRedisTemplate stringRedisTemplate(LettuceConnectionFactory redisConnectionFactory) {
// Configure redisTemplate
StringRedisTemplate stringRedisTemplate = new StringRedisTemplate();
stringRedisTemplate.setConnectionFactory(redisConnectionFactory);
/ / Open transaction support
stringRedisTemplate.setEnableTransactionSupport(true); // 2
return stringRedisTemplate;
}
#Bean
public PlatformTransactionManager transactionManager() throws SQLException {
return new DataSourceTransactionManager(dataSource()); // 3
}
#Bean
public DataSource dataSource() throws SQLException {
// ...
}
}
Updated :
Currently configured datasource properties in apppication.properties file.
# OracleDB connection settings
spring.datasource.url=jdbc:oracle:thin:#192.168.20.108:1521:orcl
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=oracle.jdbc.driver.OracleDriver
# HikariCP settings
spring.datasource.hikari.minimumIdle=5
spring.datasource.hikari.maximumPoolSize=20
spring.datasource.hikari.idleTimeout=30000
spring.datasource.hikari.maxLifetime=2000000
spring.datasource.hikari.connectionTimeout=30000
spring.datasource.hikari.poolName=redis-sample-pool
Resource about the Redis Transactions handling
There're two ways to configure DataSource
Using the config file
spring.datasource.url= jdbc:oracle:thin:#//localhost
spring.datasource.username=test
spring.datasource.password=test1234
spring.datasource.driver-class-name=oracle.jdbc.OracleDriver
#hibernate config dialect for JPA, choose dialect based on the db version
spring.jpa.database-platform=org.hibernate.dialect.Oracle10gDialect
You can create manually the same by reading these properties, with the help of DataSourceBuilder
#Bean
public DataSource dataSource(){
DataSourceBuilder dataSourceBuilder = DataSourceBuilder.create();
dataSourceBuilder.driverClassName("oracle.jdbc.OracleDriver");
dataSourceBuilder.url("jdbc:h2:mem:test");
dataSourceBuilder.username("test");
dataSourceBuilder.password("test1234");
return dataSourceBuilder.build();
}

Configuring a Spring Cloud Data Flow Task with its own Database

I have a task application with its own database that I'd like to run in Spring Cloud Data Flow.
My problem is that SCDF overwrites the datasource configuration in the task with the datasource configuration for SCDF. (Both databases are Oracle DBs.)
My task should write to a different database (but I also want to know its status in SCDF database).
How is it possible to configure my task to connect to its own database as well as to SCDF's database?
I found the solution.
I defined both data sources in a configuration class (one for JPA and one for SCDF) following this as an example: https://www.baeldung.com/spring-data-jpa-multiple-databases
However this wasn't enough because the Data Flow Server accepts only one data source by default. To overcome this, one needs to extend the DefaultTaskConfigurer and set the Data Flow Server's data source in the constructor.
#Component
public class GeneratorTaskConfigurer extends DefaultTaskConfigurer {
public GeneratorTaskConfigurer(#Qualifier("dataflowDataSource") DataSource dataSource) {
super(dataSource);
}
}
You can have one config class with SCDF datasource code like this
#Configuration
#Profile("cloud")
public class MySqlConfiguration {
#Bean
public Cloud cloud() {
return new CloudFactory().getCloud();
}
#Bean
#Primary
public DataSource dataSource() {
return cloud().getSingletonServiceConnector(DataSource.class, null);
}
#Bean
#Primary
public PlatformTransactionManager getTransactionManager() {
return new DataSourceTransactionManager(dataSource());
}
#Bean
public JobRepository jobRepositoryFactoryBean() throws Exception{
JobRepositoryFactoryBean factory = new JobRepositoryFactoryBean();
factory.setDataSource(dataSource());
factory.setTransactionManager(getTransactionManager());
factory.afterPropertiesSet();
return factory.getObject();
}
#Bean
#Primary
public DefaultTaskConfigurer defaultTaskConfigurer() {
return new DefaultTaskConfigurer(dataSource());
}
}
And then have your other datasource configuration in a separate class for the database you want to write to.
Make sure you mark the SCDF one #Primary, otherwise you get multiple datasource error.
Hope this helps.

How can I use different variable names for common Spring Boot Application Properties, when the app never directly calls these variables?

I've created a pretty standard Spring Boot 2.0 app with Services and Repositories to access a database.
I had to set the standard Spring Boot application properties to get it to work, such as:
spring.datasource.url, spring.jpa.database, etc.
However, in order to prevent my properties from overwriting other properties in similar apps hosted in the same place, I need to rename these properties, such as:
myApp.spring.datasource.url, myApp.spring.jpa.database, etc.
Some of these properties will be set by environmental variables instead of the application.properties file.
However, I can't see any way to override those variables in my app.
The standard approach is to use #Value to configure those variables. However, the Spring Boot 2.0 setup for services looks up all these properties "behind the scenes," so that doesn't appear to be an option here.
Is there any way to configure my app to read all those myApp.common.property.name properties and treat them as common.property.name?
Thank you.
Yes, the standard way is to use #Value. But thw work doesn't stop there, you need to create DataSource and EntityManager with these values.
Springboot will create DataSource, Entitymanager and some other components bey looking into default properties(spring.xxx) from the file(hence Spring boot is opinionated). But when you change these names to non default values, then you need to create these components / beans yourself.
Instead of using #Value you could also use #Configurationproperties. #Value also works but you might need to declare like 6 or 7 values with #Value. If you wish to use #ConfigurationProperties, make sure you have #EnableConfigurationProperties annotation added somewhere in your project.
Here is a code snippet. You need to tune it to your project
#Configuration
#EnableTransactionManagement
#EnableJpaRepositories(
entityManagerFactoryRef = "entityManagerFactory",
basePackages = { "com.xxx.yyy.repo" }
)
public class SomeDbConfig {
#Primary // Use this if you have multiple datasources or else no use
#Bean(name = "dataSource")
#ConfigurationProperties(prefix = "myApp.spring.datasource")
public DataSource dataSource() {
return DataSourceBuilder.create().build();
}
#Primary
#Bean(name = "entityManagerFactory")
public LocalContainerEntityManagerFactoryBean
entityManagerFactory(
EntityManagerFactoryBuilder builder,
#Qualifier("dataSource") DataSource dataSource
) {
return builder
.dataSource(dataSource)
.packages("com.xxx.yyy.domain")
.persistenceUnit("somename")
.build();
}
#Primary
#Bean(name = "transactionManager")
public PlatformTransactionManager transactionManager(
#Qualifier("entityManagerFactory") EntityManagerFactory
entityManagerFactory
) {
return new JpaTransactionManager(entityManagerFactory);
}
}

Mark externally-declared bean as #Primary

I have a Spring Boot app that requires multiple datasources that will be used via JdbcTemplates to make sql statements to different DBs. These datasource beans are already declared in external dependencies that I am pulling into my app via an #Import statement the JdbcTemplate-bean-declaring java-based #Configuration classes.
After declaring two different JdbcTemplates initialized with two different DataSource beans form these external dependencies, I run into the following error on app startup:
Parameter 0 of constructor in org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration required a single bean, but 2 were found:
Given that I don't have access to the declarations of these DataSource beans in my app, how can I mark one as #Primary?
EDIT: Here's code for the construction of the JdbcTemplates (Note "dataSourceA" and "dataSourceB" are pulled from an external dependency)
#Configuration
#Import({DataSourceAApplicationConfig.class, DataSourceBApplicationConfig.class})
public class JdbcTemplateAppConfig {
#Autowired
DataSource dataSourceA;
#Autowired
DataSource dataSourceB;
#Bean
#Primary
public JdbcTemplate jdbcTemplateForDataSourceA(#Qualifier("dataSourceA") DataSource dataSource) {
JdbcTemplate template = new JdbcTemplate(dataSource);
return template;
}
#Bean
public JdbcTemplate jdbcTemplateForDataSourceB#Qualifier("dataSourceB") DataSource dataSource){
JdbcTemplate template = new JdbcTemplate(dataSource);
return template;
}
}

Setting Spring Batch meta data Repository

I am running a Spring Batch job and have two DataSource's configured like such:
#Bean
#Primary
#ConfigurationProperties(prefix="spring.datasource")
public DataSource mainDataSource() {
return DataSourceBuilder.create().build();
}
#Bean("SpringBatchDataSource")
#ConfigurationProperties(prefix="spring.batch.datasource")
public DataSource batchDataSource() {
return DataSourceBuilder.create().build();
}
As you can see of the two DataSources I have one is just for the Spring batch metadata.
This issue I'm having is Spring batch wants to use the #Primary DataSource. How can I configure it to use the batchDataSource?

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