Spring Boot Banner Generator

Spring Boot banner generator provides the ability to customize the startup banner which is displayed before the application starts. Customizing this banner can add a unique touch to your Spring Boot application, making it stand out or providing information at startup. This guide will provide you with practical methods for generating and customizing the banner in your Spring Boot application using Kotlin.

Solution

1. Customizing the Banner Using banner.txt

One of the simplest ways to customize the Spring Boot startup banner is by using a banner.txt file.

Step-by-Step Guide:

1. Create a file named banner.txt in the src/main/resources directory of your Spring Boot application.
2. Add your desired ASCII art or text to the banner.txt file.

Example Code:

  ____             _              ____              _   
 |  _ \  ___   ___| | _____ _ __ | __ )  ___   ___ | |_ 
 | | | |/ _ \ / __| |/ / _ \ '__||  _ \ / _ \ / _ \| __|
 | |_| | (_) | (__|   <  __/ |   | |_) | (_) | (_) | |_ 
 |____/ \___/ \___|_|\_\___|_|   |____/ \___/ \___/ \__|

Kotlin Output:
When you run your Spring Boot application, you will see your custom banner printed to the console.

Advantages:

• Simple: Easy to create and manage.
• Quick: Minimal effort required to add a custom touch.

Disadvantages:

• Limited: Only allows for text and simple ASCII art.
• No Runtime Customization: Static content that cannot be modified dynamically.

2. Customizing the Banner Using Code-Based Approach

Using a code-based approach allows you to generate dynamic content for the banner.

Step-by-Step Guide:

1. Create a custom Banner implementation.
2. Set the custom banner in your Spring Boot application’s main class.

Example Code:

import org.springframework.boot.Banner
import org.springframework.boot.SpringApplication
import org.springframework.boot.autoconfigure.SpringBootApplication
import java.io.PrintStream

@SpringBootApplication
class CustomBannerApplication

class CustomBanner : Banner {
    override fun printBanner(environment: org.springframework.core.env.Environment, sourceClass: Class<*>, out: PrintStream) {
        out.println("  ____  _                   _ ")
        out.println(" | __ )| | ___  _   _  __ _| |")
        out.println(" |  _ \\| |/ _ \\| | | |/ _` | |")
        out.println(" | |_) | | (_) | |_| | (_| | |")
        out.println(" |____/|_|\\___/ \\__, |\\__,_|_|")
        out.println("               |___/         ")
    }
}

fun main(args: Array<String>) {
    val app = SpringApplication(CustomBannerApplication::class.java)
    app.setBanner(CustomBanner())
    app.run(*args)
}

Output:
When you run the application, the custom banner defined in CustomBanner class will be printed.

Advantages:

• Dynamic Content: Allows for dynamic content based on the environment.
• Flexible: Full control over the banner content and formatting.

Disadvantages:

• Complexity: More complex than using a banner.txt file.

3. Using Spring Boot Properties

Spring Boot allows customization of the banner via properties as well. You can control various aspects of the banner through the application.properties file.

Step-by-Step Guide:

1. Add properties for the banner in application.properties.

Example Code:

spring.banner.location=classpath:custom-banner.txt
spring.banner.image.location=classpath:banner.png
spring.banner.image.width=76
spring.banner.image.height=10
spring.banner.image.margin=2
spring.banner.image.invert=true

Output:
Depending on your properties, the banner from the specified location or the image will be displayed.

Advantages:

• Simple Configuration: Easy to manage through property files.
• Supports Images: Ability to use images as banners.

Disadvantages:

• Static Configuration: Properties are static and cannot be changed at runtime.

4. Combining Static and Dynamic Content

For more advanced customizations, you can combine both banner.txt file and dynamic content using the Banner interface.

Step-by-Step Guide:

1. Create a custom Banner implementation to extend the static content from banner.txt.

Example Code:

import org.springframework.boot.Banner
import org.springframework.boot.SpringApplication
import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.core.env.Environment
import java.io.PrintStream

@SpringBootApplication
class CustomBannerApplication

class CompositeBanner : Banner {
    override fun printBanner(environment: Environment, sourceClass: Class<*>, out: PrintStream) {
        // Print static content from banner.txt
        val resource = sourceClass.getResourceAsStream("/banner.txt")
        resource?.bufferedReader()?.forEachLine { out.println(it) }
        
        // Print dynamic content
        out.println(":: Spring Boot ::  ${environment.activeProfiles.joinToString(", ")}")
    }
}

fun main(args: Array<String>) {
    val app = SpringApplication(CustomBannerApplication::class.java)
    app.setBanner(CompositeBanner())
    app.run(*args)
}

Output:
Static content from banner.txt followed by dynamic content is displayed.

Advantages:

• Hybrid Approach: Combines both static and dynamic content.
• Customizable: Flexible and customizable based on requirements.

Disadvantages:

• Complexity: Slightly more complex to implement and manage multiple sources for banner content.

Similar Topics

• How to customize Spring Boot startup logs?
• How to disable the Spring Boot banner?
• How to use environment variables in a Spring Boot banner?
• How to add color to the Spring Boot banner?
• How to include application version in the Spring Boot banner?
• Spring Boot logging levels and configuration
• Using images and logos in Spring Boot banner
• Changing banner font style in Spring Boot
• Spring Boot banner best practices
• Troubleshooting Spring Boot banner issues
• Spring Boot properties for application customization
• How to use ASCII art for Spring Boot banner?
• Spring Boot command-line banner customization
• Spring Boot banner with application context information
• Adding a personalized message to Spring Boot banner

By customizing the Spring Boot banner, you can make your application’s startup phase more informative and visually appealing, whether it be through straightforward text files or more intricate code-based solutions.