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The PropertyKey class provides a unified way to access configuration values from both environment variables and Java system properties, with automatic camelCase to CONSTANT_CASE conversion.

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Package

me.hsgamer.mcreleaser.core.property.PropertyKey

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Class Declaration

public class PropertyKey {
    private final String key;
    private final String env;
}

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Constructors

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PropertyKey(String key, String env)

Creates a PropertyKey with explicit property key and environment variable names.
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key
String
required
The system property key name
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env
String
required
The environment variable name
PropertyKey token = new PropertyKey("github.token", "GITHUB_TOKEN");

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PropertyKey(String key)

Creates a PropertyKey with automatic environment variable name conversion from camelCase to CONSTANT_CASE.
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key
String
required
The system property key name (camelCase)
// Automatically creates env var "GITHUB_TOKEN" from "githubToken"
PropertyKey token = new PropertyKey("githubToken");

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Methods

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getKey

Returns the system property key name.
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key
String
The system property key
String key = propertyKey.getKey(); // "githubToken"

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getEnv

Returns the environment variable name.
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env
String
The environment variable name
String env = propertyKey.getEnv(); // "GITHUB_TOKEN"

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getValue

Retrieves the property value, checking environment variables first, then system properties.
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value
String
The property value, or null if not found
String value = propertyKey.getValue();

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getValue(String defaultValue)

Retrieves the property value with a fallback default.
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defaultValue
String
required
The default value to return if the property is not found
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value
String
The property value, or the default value if not found
String version = versionKey.getValue("1.0.0");

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setValue(String value)

Sets the property value as a system property.
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value
String
required
The value to set
propertyKey.setValue("my-value");

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setValue(Object value)

Sets the property value from any object using toString().
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value
Object
required
The object to convert to a string and set
propertyKey.setValue(123);
propertyKey.setValue(true);

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isPresent

Checks if the property has a value.
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present
boolean
True if the property value is not null
if (propertyKey.isPresent()) {
    // Use the value
}

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isAbsent

Checks if the property has no value.
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absent
boolean
True if the property value is null
if (propertyKey.isAbsent()) {
    logger.warn("Property not configured");
}

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asNumber

Parses the property value as a number.
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defaultValue
Number
required
The default value to return if parsing fails or property is absent
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number
Number
The parsed number, or the default value
Number timeout = timeoutKey.asNumber(5000);

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asBoolean

Parses the property value as a boolean.
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defaultValue
boolean
required
The default value to return if property is absent
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boolean
boolean
The parsed boolean, or the default value
boolean isDraft = draftKey.asBoolean(false);

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CamelCase to CONSTANT_CASE Conversion

The automatic conversion transforms property keys: 
"githubToken"      → "GITHUB_TOKEN"
"versionType"      → "VERSION_TYPE"
"gameVersions"     → "GAME_VERSIONS"
"announceMissingKey" → "ANNOUNCE_MISSING_KEY"

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Property Resolution Order

  1. Environment variable (e.g., GITHUB_TOKEN)
  2. System property (e.g., github.token)
  3. Default value (if provided)
  4. null (if no default)

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Example Usage

// Define property keys
public interface MyAppConfig {
    PropertyKey API_KEY = new PropertyKey("apiKey");
    PropertyKey TIMEOUT = new PropertyKey("timeout");
    PropertyKey DEBUG = new PropertyKey("debug");
}

// Use in application
String apiKey = MyAppConfig.API_KEY.getValue();
Number timeout = MyAppConfig.TIMEOUT.asNumber(3000);
boolean debug = MyAppConfig.DEBUG.asBoolean(false);

if (MyAppConfig.API_KEY.isAbsent()) {
    throw new IllegalStateException("API key required");
}

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