import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.*;
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// Input:
		String queryText = " SELECT stuff FROM stufftable WHERE oid_2 = $$test$$ || oid_2 = $$test2$$"; 
		String test = "1";
		String test2 = "2";
		Map<String, String> map = new HashMap<>();
		map.put("test", test);
		map.put("test2", test2);

		StringBuffer result = new StringBuffer();
		Matcher m = Pattern.compile("\\${2}(.*?)\\${2}").matcher(queryText);
		while (m.find()) {
    		if (!m.group(1).isEmpty()) {
		    	m.appendReplacement(result, map.get(m.group(1)));
    		}
		    else {
			   m.appendReplacement(result, m.group(0));
		    }
		}
		m.appendTail(result);
		System.out.println(result.toString());

	}
}