Spring Boot Hot Deployment Techniques: Disabling Template Cache, Debug Mode, DevTools, Spring Loaded, and JRebel

The author, a senior architect, shares several practical methods for hot deployment in Spring Boot applications.

1. Disable Template Engine Cache

Spring Boot caches templates by default; to see changes instantly, set the cache property to false for each engine.

spring.thymeleaf.cache=false

spring.freemarker.cache=false

spring.groovy.template.cache=false

spring.velocity.cache=false

2. Debug Mode Hot Deployment

Running the application in Debug mode provides a quick hot‑deployment approach without additional plugins, though it cannot handle changes to configuration files or method signatures.

3. Spring Boot DevTools

Adding the spring-boot-devtools dependency enables automatic restart and live reload for both pages and code.

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-devtools</artifactId>
</dependency>

4. Spring Loaded

Spring Loaded works like Debug mode but does not require the JVM to start in debug; it can be configured in the run configuration to achieve real‑time hot deployment.

5. JRebel

JRebel is a commercial tool offering extensive hot‑deployment support for Spring Boot, with a 14‑day trial.