SimpleConfig

SimpleConfig is a lightweight and flexible Java configuration library that binds static fields in classes to external configuration files, enabling real-time updates and advanced management. It supports dynamic field updates, multiple configuration files, remote synchronization, and integration with third-party libraries.

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Key Features

• Dynamic Field Updates: Automatically updates static fields after configuration changes with minimal delay (~10 seconds by default).
• Broad Data Type Support: Compatible with primitive types, arrays, List, Set, Map, and nested types.
• Multiple Configuration Files: Manage multiple configuration files for complex applications.
• Remote Synchronization: Keep configurations synchronized with remote servers.
• Third-Party Support: Modify private static fields in third-party classes.
• Action-Based Commands: Perform various actions like generating, validating, encoding, decoding, and synchronizing configurations via command-line arguments.

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Installation

1. Add SimpleConfig to your project (via Maven, Gradle, or manually).
2. Define a configuration file (e.g., server.ini) and bind it to your application's configuration class.

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Usage Guide

1. Define a Configuration Class

Create a Java class with static fields to store your application's configuration values:

public class PiledConfig {
    public static int coreThreads = 20;
    public static int maxThreads = 128;
    public static int idleThreads = 5;
    public static int threadIdleSeconds = 60;
    public static int maxQueueRequests = 1000;
}

2. Use Static Fields in Your Application

Access static fields directly to configure your application logic:

workerPool = new SimpleThreadPoolExecutor(
    PiledConfig.coreThreads,
    PiledConfig.maxThreads <= 0 ? Integer.MAX_VALUE : PiledConfig.maxThreads,
    Math.max(PiledConfig.idleThreads, 1),
    PiledConfig.threadIdleSeconds,
    TimeUnit.SECONDS,
    PiledConfig.maxQueueRequests,
    new SimpleNamedThreadFactory("Worker Pool")
);

if (lastCoreThreads != PiledConfig.coreThreads) {
    workerPool.setCorePoolSize(PiledConfig.coreThreads);
}
if (lastMaxThreads != PiledConfig.maxThreads) {
    workerPool.setMaximumPoolSize(PiledConfig.maxThreads);
}

3. Initialize Configuration on Startup

Bind your configuration class to a configuration file during application startup:

	public static void main(String[] args) {
		args = Config.initialize(args); // Remove known configuration argument items and return left arguments
		Config.register(PiledConfig.class);
		// Application initialization logic...
	}

Or using --run:wrapper to run your application without modifying your existing code. See 5. Command-Line Actions.

4. Edit Configuration File

Define your configuration values in an external file (e.g., server.ini):

# PiledConfig
coreThreads=20
maxThreads=128
idleThreads=5
threadIdleSeconds=60
maxQueueRequests=1000

5. Command-Line Actions

You can perform various actions using command-line arguments with the --run:<action> flag:

• usage: Print the usage instructions.
• generator: Generate default configuration files.
• encoder: Encode a sensitive string (e.g., passwords).
• decoder: Decode an encoded string back to its original value.
• validator: Validate the structure and contents of configuration files.
• synchronizer: Synchronize configuration files with remote servers.
• wrapper: Dynamically run another application's main method while inheriting its configuration.

Example Command:

java -jar myapp.jar im.webuzz.config.Config --run:usage

java -jar myapp.jar im.webuzz.config.Config ./server.ini --run:generator

java -jar myapp.jar im.webuzz.config.Config --config:app.name=CRM ./server.ini --run:wrapper com.company.CRMApplication

Advanced Features

• File Change Detection: Automatically detects changes in the configuration file and applies updates without requiring application restarts.
• Nested Configuration Support: Handles nested types and complex structures in configuration classes.
• Dynamic Command Execution: Use the wrapper action to execute the main method of any Java class with the existing configuration.

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License

This library is distributed under the Eclipse Public License 1.0, which allows for both commercial and non-commercial usage.

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Contributing

We welcome contributions! Feel free to submit issues, feature requests, or pull requests to improve SimpleConfig.

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With SimpleConfig, streamline your application's configuration management and focus on building amazing software! 🚀