JLightConfig

Introduction

A Java lightweight configuration framework for all kinds of configurations (commandline, files, etc.)

Feature

• Zero configuration: No file configurations, all in codes
• Extensive: Just extends the abstract class or interface
• Lightweight: A few dependencies, make up a world

Installation

Maven

<dependency>
  <groupId>io.tomahawkd</groupId>
  <artifactId>jlightconfig</artifactId>
  <version>1.0.1</version>
</dependency>

Usage

Note: The example below is already integrated in this repo

Step 1: Build up your config

• Extends abstract class AbstactConfig and define your parse method

Example (with dependency com.beust.jcommander:1.69):

@SourceFrom(CommandlineConfigSource.class)
public class CommandlineConfig extends AbstractConfig {

  @HiddenField
  private JCommander c;

  @Override
  public final void parse(@NotNull ConfigSource source) {
    c = JCommander.newBuilder().addObject(this)
             .addObject(getDelegates()).build();

    try {
      c.parse((String[]) source.getData());
    } catch (ParameterException e) {
      System.err.println(e.getMessage());
      c.usage();
      throw e;
    }
  }

  public String usage() {
    StringBuilder builder = new StringBuilder();
    c.usage(builder);
    return builder.toString();
  }
}

Step 2: Add delegates to your config (optional)

• Create delegates to parse and receive config data

• Use annotation BelongsTo to your Delegate bind your config and delegate

Note: You may use AbstractConfigDelegate.getField(String key, Class<T> type) to get data from your configs or delegates

Example:

@BelongsTo(CommandlineConfig.class)
public class TestDelegate extends AbstractConfigDelegate {

  @Parameter(names = {"-h", "--help"}, help = true,
             description = "Prints usage for all the existing commands.")
  private boolean help;

  public boolean isHelp() {
    return help;
  }
}

Step 3: Declare the source of your config

• Implements interface ConfigSource and implements how data could be received.

• Use annotation SourceFrom to your Config to bind source and config

Example:

public class CommandlineConfigSource implements ConfigSource {

  private String[] data;

  public void setData(String[] data) {
    this.data = data;
  }

  @Override
  public String[] getData() {
    return data;
  }
}

Step 4: Bring up your system

• Use SourceManager and ConfigManager to run your project.

Example:

class Test {
  // args: --help
  public static void main(String[] args) {
    SourceManager sourceManager = SourceManager.get();
    ConfigManager configManager = ConfigManager.get();

    sourceManager.getSource(CommandlineConfigSource.class).setData(args);
    configManager.parse();
    
    // you would get true
    configManager.getConfig(CommandlineConfig.class)
            .getDelegateByType(TestDelegate.class).isHelp();

    // or you could use
    configManager.getConfig(CommandlineConfig.class)
            .getDelegateByString("io.tomahawkd.config.delegate.TestDelegate")
            .getField("help", boolean.class);
  }
}

Known Issues

• Test failed in maven
  While maven testing the sources, it could report Reflections Scanner was not configured ronmamo/reflections (#273)

License

This repo is under Apache v2.0 license