An example of using an Enum class as a Singleton

EnumSingletonExample.java

// Using an Enum as a Singleton
//
public enum TestDAO {

	// Our one and only instance
        instance;

	private DataSource dataSource = new DataSource();

	// private constructor to prevent any instantiations
        private TestDAO() {
		dataSource.setName("myDatabaseName");
		dataSource.setUrl("jdbc:/myUrl/next/other/");

	}

	public DataSource getDataSource() {
		return dataSource;
	}

	public void moreUsefulMethodsHere(String... strings) {
		// ** Cool stuff ??
	}

}


// The app
public class Main {

	public static void main(String... args) {
		
		// Obtain the only instance...
                DataSource ds = TestDAO.instance.getDataSource();


		System.out.println("URL = " + ds.getUrl());
	}
	
}


// Simple bean
public class DataSource {
	
	private String url;
	private String name;

	public String getUrl() {
		return url;
	}
	public void setUrl(String url) {
		this.url = url;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
}