Creating an end-to-end Spring Boot WebFlux batch API to read data from Teradata involves several steps. I’ll provide a comprehensive example that includes:
- Spring Boot application setup with WebFlux
- Reactive repository to fetch data from Teradata
- Controller to expose the API
- Basic configuration for connecting to Teradata
Since WebFlux is reactive, you should use a reactive driver for Teradata. However, Teradata’s official Reactive driver support is limited. But for the purpose of this example, I will demonstrate how you might set up a reactive API assuming the availability of a reactive driver or by wrapping blocking calls in a reactive manner with Mono.fromCallable() or similar.
Step 1: Dependencies (Spring Boot + WebFlux + R2DBC + Teradata)
Include the following dependencies in your pom.xml. Note that Teradata does not officially support R2DBC, but you might need a driver or fallback to using JdbcTemplate with Mono.fromCallable() for blocking calls.
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<!-- If you have a reactive Teradata driver, include it here, for example: -->
<!-- dependency for hypothetical Teradata R2DBC driver -->
<!-- <dependency>
<groupId>com.teradata</groupId>
<artifactId>teradata-r2dbc</artifactId>
<version>1.0.0</version>
</dependency> -->
<!-- Alternatively, fallback with R2DBC Postgres or H2 for testing -->
<dependency>
<groupId>io.r2dbc</groupId>
<artifactId>r2dbc-spi</artifactId>
<version>0.8.12.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-r2dbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
Step 2: Application Configuration
Create application properties for Teradata connection (adjust as per your environment):
# src/main/resources/application.properties
spring.r2dbc.url=r2dbc:teradata://host:port/database
spring.r2dbc.username=your_username
spring.r2dbc.password=your_password
Note: Replace the URL with the correct Teradata R2DBC URL when available.
Step 3: Data Model
Create a simple data class representing the data:
package com.example.teradataspring.model;
public class DataRecord {
private Long id;
private String data;
// Constructors
public DataRecord() {}
public DataRecord(Long id, String data) {
this.id = id;
this.data = data;
}
// Getters and Setters
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getData() {
return data;
}
public void setData(String data) {
this.data = data;
}
}
Step 4: Repository Layer
Since there’s no native reactive driver, here’s an example wrapping blocking JDBC calls with Mono.fromCallable(). Alternatively, if using a reactive driver, you would implement accordingly.
package com.example.teradataspring.repository;
import com.example.teradataspring.model.DataRecord;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.r2dbc.core.DatabaseClient;
import reactor.core.publisher.Flux;
public class BatchRepository {
private final DatabaseClient databaseClient;
@Autowired
public BatchRepository(DatabaseClient databaseClient) {
this.databaseClient = databaseClient;
}
public Flux<DataRecord> fetchData() {
String query = "SELECT id, data FROM your_table"; // your table name
return databaseClient.sql(query)
.map((row, rowMetadata) -> new DataRecord(
row.get("id", Long.class),
row.get("data", String.class)
))
.all();
}
}
Note: You need to register BatchRepository as a bean or annotate with @Repository.
Step 5: Service Layer
package com.example.teradataspring.service;
import com.example.teradataspring.model.DataRecord;
import com.example.teradataspring.repository.BatchRepository;
import org.springframework.stereotype.Service;
import reactor.core.publisher.Flux;
@Service
public class DataService {
private final BatchRepository batchRepository;
public DataService(BatchRepository batchRepository) {
this.batchRepository = batchRepository;
}
public Flux<DataRecord> getAllData() {
return batchRepository.fetchData();
}
}
Step 6: Controller for regular applications
package com.example.teradataspring.controller;
import com.example.teradataspring.model.DataRecord;
import com.example.teradataspring.service.DataService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import reactor.core.publisher.Flux;
@RestController
public class DataController {
private final DataService dataService;
public DataController(DataService dataService) {
this.dataService = dataService;
}
@GetMapping("/api/data")
public Flux<DataRecord> getData() {
return dataService.getAllData();
}
}
Step 7: Scheduler (Batch job with @Scheduled)
// BatchScheduler.java
package com.example.demo.scheduler;
import com.example.demo.model.DataRecord;
import com.example.demo.service.DataService;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import reactor.core.publisher.Flux;
@Component
public class BatchScheduler {
private final DataService dataService;
public BatchScheduler(DataService dataService) {
this.dataService= dataService;
}
@Scheduled(fixedDelay = 60000) // runs every 60 seconds
public void runBatchJob() {
dataService.getAllData()
.doOnNext(record -> {
// process each record, e.g., log or store
System.out.println("Processing record: " + record.getId() + ", data: " + record.getData());
})
.subscribe(); // trigger the reactive flow
}
}
Step 8: Main Application Class for normal application
package com.example.teradataspring;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.r2dbc.core.DatabaseClient;
import com.example.teradataspring.repository.BatchRepository;
@SpringBootApplication
public class TeradataSpringBootApplication {
public static void main(String[] args) {
SpringApplication.run(TeradataSpringBootApplication.class, args);
}
@Bean
public BatchRepository batchRepository(DatabaseClient databaseClient) {
return new BatchRepository(databaseClient);
}
}
Step 9: Main Application Class for Scheduler application
// DemoApplication.java
package com.example.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;
@SpringBootApplication
@EnableScheduling
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
This setup creates a reactive Spring Boot API using WebFlux to read data from Teradata. It leverages DatabaseClient for reactive database access, which is part of Spring Data R2DBC. If you don’t have a reactive driver for Teradata, you’ll need to adapt the code to wrap blocking calls appropriately.
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