Java Singleton Pattern

• 문제
  
• 정답

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
import java.lang.reflect.*;


class Singleton{
    public String str;

    private static Singleton instance;

    private Singleton() {}

    public static Singleton getSingleInstance() {
        if (instance == null) {
            instance = new Singleton();
        }
        return instance;
    }
}

• 결과