Implementing a global configuration using a Singleton class in Java

Category : Design Patterns | Sub Category : Questions on Design Patterns | By Prasad Bonam Last updated: 2023-07-12 02:31:56 Viewed : 348

Implementing a global configuration using a Singleton class in Java:

Here is an example of implementing a global configuration using a Singleton class in Java:

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import java.util.Properties;

public class GlobalConfiguration {
    private static GlobalConfiguration instance;
    private Properties properties;

    private GlobalConfiguration() {
        properties = new Properties();
        // Load configuration properties from a file or other sources
        // Example: properties.load(new FileInputStream("config.properties"));
        // Set properties programmatically
        properties.setProperty("key1", "value1");
        properties.setProperty("key2", "value2");
    }

    public static synchronized GlobalConfiguration getInstance() {
        if (instance == null) {
            instance = new GlobalConfiguration();
        }
        return instance;
    }

    public String getProperty(String key) {
        return properties.getProperty(key);
    }

    // Other methods for configuration management...
}

In this example, the GlobalConfiguration class is implemented as a Singleton using a private constructor and a static getInstance() method.

The GlobalConfiguration class maintains a Properties object to store configuration properties. In the constructor, you can load the properties from a file or set them programmatically as shown in the example.

The getProperty() method allows you to retrieve a configuration property based on a given key.

To use the GlobalConfiguration class, you can retrieve the singleton instance using GlobalConfiguration.getInstance() and then call the getProperty() method to access configuration properties:

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GlobalConfiguration config = GlobalConfiguration.getInstance();
String value1 = config.getProperty("key1");
String value2 = config.getProperty("key2");
// ...

// Use the configuration properties as needed

Note that this is a basic example to illustrate the Singleton pattern and global configuration management. In a real-world scenario, you may need to handle configuration loading, validation, updating, and other aspects based on your specific requirements. Additionally, consider using configuration management frameworks such as Apache Commons Configuration or Spring Boots configuration support for more advanced configuration features and flexibility.