Implementation of hot deployment of SpringBoot project

Spring Boot project hot deployment is a development-time optimization technology that allows developers to see the modification effect in real time without restarting the application after modifying the code. In traditional development models, every time you modify the code, you need to recompile, package and deploy the application, which will waste a lot of time. Using hot deployment technology, developers only need to save the modified code, and the application will automatically recognize and load the modified code, thereby achieving real-time preview. This can greatly improve development efficiency and speed up the development cycle. Spring Boot project hot deployment can be achieved by using Spring Boot's development toolkit (DevTools). You only need to add corresponding dependencies to the project and then enable the hot deployment function when starting the project.

application

When developing Spring Boot projects, being able to reload code changes (hot deployment) without restarting the server is important to improve development efficiency. Spring Boot provides several ways to achieve hot deployment. Here are several commonly used hot deployment methods:

1. Use Spring Boot DevTools

Spring Boot DevTools is a toolkit designed specifically for convenience during the development process. It supports automatic restart, LiveReload and other functions, greatly facilitating development and debugging.

a. Add DevTools dependencies

First, in the projectFile orAdd to the filespring-boot-devtoolsDependence.

• If using Maven:

<dependency>
    <groupId></groupId>
    <artifactId>spring-boot-devtools</artifactId>
    <optional>true</optional>
</dependency>

• If using Gradle:

implementation ':spring-boot-devtools'

b. Enable automatic restart

spring-boot-devtoolsThe automatic restart function is enabled by default. Spring Boot DevTools automatically restarts the application whenever a class or resource file in the project changes, but does not require manual restart of the entire server.

• Automatic restart: detected on the classpath.classWhen the file changes, the application will automatically restart. This method is achieved by reloading the class loader and is faster.
• LiveReload Support: DevTools also integrates LiveReload, and the browser will automatically refresh when resources (such as HTML, CSS, JS) files change.

c. Configure DevTools

You can passorFile further configuration DevTools. For example:

# Enable or disable DevTools automatic restart feature=true

# Set files or folders that are ignored during automatic restart=static/**,public/**

# Set additional paths for monitoring during restart-paths=src/main/java

# Enable or disable LiveReload=true

2. Use the IDE's hot deployment capabilities

Most popular IDEs such as IntelliJ IDEA, Eclipse, Spring Tool Suite (STS) provide hot deployment capabilities to reload changes without restarting the server.

a. IntelliJ IDEA

In IntelliJ IDEA, the following settings can help you achieve hot deployment:

• Enable automatic compilation:

  • OpenFile -> Settings -> Build, Execution, Deployment -> Compiler -> Build project automatically。
  • On Mac, openIntelliJ IDEA -> Preferences -> Build, Execution, Deployment -> Compiler -> Build project automatically。

• Enable runtime automatic compilation:

  • PressCtrl + Shift + A(Windows/Linux) orCommand + Shift + A(Mac), searchRegistryand open.
  • Check。

b. Eclipse / Spring Tool Suite (STS)

In Eclipse or Spring Tool Suite, the following settings can be enabled:

• Automatic build:

  • OpenProjectMenu, checkBuild Automatically。

• Hot deployment settings:

  • Right-click on the project and selectProperties -> Server -> Automatically publish when resources change。
  • Set to Publish Now, or adjust the time interval according to your needs.

3. Use JRebel

JRebel is a commercial Java development tool focused on providing powerful hot deployment capabilities. JRebel supports dynamic loading of changes to classes without restarting the JVM (including adding new methods, modifying existing methods, updating annotations, etc.).

a. Integration of JRebel

• Install the JRebel plugin to your IDE (such as IntelliJ IDEA or Eclipse).
• Add JRebel to your project and start the project with JRebel.

JRebel offers more features than DevTools, but it costs a fee.

4. Use Spring Loaded (no longer maintained)

Spring Loaded is a hot deployment tool that Spring official provides early, but is no longer actively maintained. Still, it can be used in some older projects.

a. Add Spring Loaded dependency

existAdd the following dependencies to:

<dependency>
    <groupId></groupId>
    <artifactId>springloaded</artifactId>
    <version>1.2.</version>
    <scope>provided</scope>
</dependency>

b. Add JVM parameters at startup

When running a Spring Boot application using Spring Loaded, you need to add the following to the JVM parameters:

-javaagent:/path/to/ -noverify

However, the use of Spring Loaded has gradually been replaced by DevTools and JRebel.

Summarize

The most commonly used and recommended way to implement hot deployment in Spring Boot projects is to use Spring Boot DevTools. It is simple and easy to use and powerful, suitable for most development scenarios. If you have more advanced requirements or use other tools such as JRebel, you can also use the IDE's hot deployment capabilities. With these tools and configurations, developers can significantly improve development efficiency and view the effects of code changes without frequent restarts of the server.

This is the end of this article about the implementation of hot deployment of SpringBoot projects. For more related hot deployment content, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!