Schedule jobs in Spring Boot 4 with Quartz 2.5: inject Spring beans into jobs, use simple and cron triggers, handle misfires, chain jobs with listeners, persist and cluster jobs with the JDBC job store, and manage them from the actuator endpoint.
Learn to write SQL queries with ‘LIKE’ keyword in a Spring Boot JPA application and execute with JdbcClient, JdbcTemplate or JpaRepository template methods.
Since Spring 6.1, JdbcClient provides a unified client API for JDBC query and update operations, offering a more fluent and simplified interaction model.
Learn to configure the Log4j2 provided JDBCAppender that writes log events to a relational database table using standard JDBC. The JDBCAppender obtains the database connection from a configured connection factory or JNDI datasource. Then it uses the provided column configuration to insert a new row in the log table, everytime a log statement is executed. … Read more
Get the current timestamp in Java with Instant.now() and currentTimeMillis(), convert to epoch millis or seconds, format it, and save it with JDBC.
Hibernate throws GenericJDBCException: could not prepare statement when the driver rejects the SQL and gives no SQLState to classify it. See the real messages from SQLite, H2 and HSQLDB on Hibernate 7.4, how to read the root SQLException, and the fix for each cause.
Using custom SQL scripts in spring to initialize the database at startup of application with appropriate tables and data populated inside it.
Spring AI 2.0 migration guide: upgrade a Spring AI 1.x app to 2.0.1 step by step, with the build errors you will see and the fix for each one.
Spring AI testing at three levels: unit tests with a fake ChatModel, integration tests with Ollama in Testcontainers, and evaluators as judges.
Build a Spring AI MCP server with @McpTool, @McpResource and @McpPrompt, test it with MCP Inspector, and call its tools from a Spring AI MCP client.
Spring AI advisors explained: how the advisor chain works, the built-in advisors, why their order matters, and how to write your own call advisor.
Spring AI vector store comparison: the same app on SimpleVectorStore, Chroma, pgvector, Redis and Qdrant, with real timings, setup, traps and a rule.
Spring AI chat memory with Ollama: add MessageChatMemoryAdvisor, keep one conversation per customer, save it in HSQLDB with JDBC and pick a window size.
Build a Spring Boot and Vaadin CRUD app with a Grid, a validated form and Spring Data JPA. Complete code for every file, run steps and real screenshots.
Spring Authorization Server issues OAuth2 access tokens and OpenID Connect ID tokens from our own Spring Boot application. This tutorial builds an authorization server and a resource server on Spring Boot 4.1, with client_credentials and PKCE clients, key rotation, custom claims, JDBC client storage, MockMvc tests and real curl output.
Spring Boot 4 is the major release built on Spring Framework 7, Jakarta EE 11 and Jackson 3, with Java 17 as the minimum. This tutorial builds one Spring Boot 4.1.1 app that shows the modular starters, JSpecify null-safety with NullAway, API versioning, HTTP service clients with @Retryable, Jackson 3, MockMvcTester and RestTestClient tests, virtual threads, OpenTelemetry traces and the 4.1 additions, and ends with an upgrade checklist from Spring Boot 3.5.
Spring Framework 7 keeps Java 17 but moves to Jakarta EE 11, JSpecify null-safety and Jackson 3. This overview lists every notable change in a summary table and shows the main new features, such as @Retryable, API versioning and BeanRegistrar, with short examples.
Spring Security 7 ships with Spring Boot 4 and removes the APIs deprecated in 6.x, such as and() chaining and AntPathRequestMatcher. This overview lists every change in one table, explains each one briefly with snippets for the main ones, and ends with a migration checklist from 6.x.
30 Java interview questions for developers with about 5 years of experience, each with a direct answer, the reason behind it and a runnable Java 25 snippet. Covers collections internals, concurrency, Java 21 to 25 features, JVM memory and GC, streams, design, Spring @Transactional pitfalls and small system design tasks.
Connect Spring Boot 4.1 to Elasticsearch 9 with Spring Data Elasticsearch 6.1 and the new Java client: run Elasticsearch in Docker, map documents, search with repositories and NativeQuery, and test with Testcontainers.
A hands-on Kubernetes guide for Java developers: deploy a Spring Boot API and PostgreSQL to a local kind cluster and learn pods, Deployments, Services, Ingress, ConfigMaps, Secrets, volumes and StatefulSets with real kubectl output.
Upload an .xlsx class roster to a Spring Boot endpoint, read it with Apache POI, validate every row with Bean Validation and save the valid rows in JDBC batches. Includes a JSON error report, duplicate checks, a SAX reader for large files with measured heap, upload limits and MockMvc tests.
Set up Hibernate 7.4 in a Spring Boot 4.1 application: the JPA starter, datasource and JPA properties, entities, Spring Data repositories, transactions, the Session API, SQL logging, tests on H2 and MySQL, and the Hibernate 7 upgrade changes.
One property, spring.threads.virtual.enabled=true, moves Spring Boot requests, @Async methods and scheduled tasks to virtual threads. A weather API measured against platform threads and WebFlux, plus pinning and monitoring on Java 25.
1. Problem When writing tests that depend on H2 database in a Spring boot application, we may encounter the CommandAcceptanceException: Error executing DDL. The root cause exception will be org.h2.jdbc.JdbcSQLSyntaxErrorException in the logs. The exception stack trace will look something like this: If you are trying to run unit tests with the H2 database and … Read more
In Spring Security, a One-Time Token (OTT) is a server-side generated string that can be used only once for user login authentication purpose.
Spring AI pgvector example: run PostgreSQL with pgvector in Docker, configure PgVectorStore, load and search documents, and fix the dimension errors.
Spring AI tool calling with Ollama: describe Java methods with @Tool, pass them to ChatClient, and handle errors, loops and tools that change data safely.
Spring AI text to SQL: turn a question into a SELECT with a ChatClient, check it, run it read-only, explain the rows and fix the model’s common SQL errors.
Learn to read all the rows from an Excel (.xls or .xlsx) file using Spring Batch and save them in a database in a Spring Boot application.
Executors.newVirtualThreadPerTaskExecutor() runs each task in a new virtual thread. Learn close(), invokeAll, Semaphore limits, thread names and errors.
Learn to Spring Data JPA module and work with JpaRepository interface for performing the CRUD operations in underlying databases in a Spring Boot application.
Spring Boot provides various ways to load property files such as default application.properties, spring profiles, custom property files, environment variables, and system properties.
SpringExtension integrates the Spring TestContext Framework into JUnit 5 Jupiter extension model, sets up the ApplicationContext, and manages dependencies.
This guide explores the step-by-step process of containerization and running a Spring Boot application with PostgreSQL database using Podman.
This Spring vs. Spring Boot tutorial lists the differences between Spring framework and Spring Boot based on general characteristics and features.
Java records cannot be used as the replacement for JPA entities because they restrict the byte code manipulation, generally required by frameworks to work.
Learn to use Spring CrudRepository and ListCrudRepository interfaces, their differences and the changes made in Spring Data 3.0 with examples.
Learn to build REST APIs in a Spring boot application with request validation, error handling, testing and API documentation with examples.
Learn the core concepts of configuring role-based authorization in Spring Security 6 and implementing authorization in a Spring Boot application.
Since Spring Boot 3.1, @ServiceConnection is used to provide connection details to a remote service that takes precedence over details in the properties file.
Learn to use Spring boot docker compose module, customize the compose file and container lifecycle with an example.
Learn the fundamentals of working with S3 buckets and objects using Spring Cloud AWS library and its S3Client and S3Template classes.
If you’re preparing for a job interview, these Spring security interview questions will help you understand key concepts and increase the confidence.
Learn to use Redis Pub/Sub with Spring Boot Data, and configure the message publishers and subscribers (listners) for a given channel topic.
WebSecurityConfigurerAdapter was deprecated in Spring Security 5.7 and removed in 6.0. Replace it with a SecurityFilterChain bean, requestMatchers, a PasswordEncoder bean, WebSecurityCustomizer and @EnableMethodSecurity on Spring Boot 4, with tests.
Add Spring Security to a Spring Boot 4 application, see what it secures by default, and write your own SecurityFilterChain with tested examples. Every Spring Security guide on the site, grouped by topic.
Step by step, we will learn to deploy a Spring Boot application to AWS Elastic Beanstalk which uses RDS for persisting the records in the database.
Learn the installation of the Keycloak authorization server as a docker container and different configurations for setting up the realm and testing the authorization token flow.
Learn to implement authentication with a user login and logout functionality using Vue.js and Spring Boot Security using JWT tokens.
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