SELECT name,
       round(((1 - (physical_reads / (consistent_gets + db_block_gets))) * 100),
             2) || '% (90%이상 권장)' "hit Ratio"
  FROM V$BUFFER_POOL_STATISTICS

 WHERE (consistent_gets + db_block_gets) != 0;

package com.test;

import java.text.Collator;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class Test {
	public static void main(String[] args) {
		
		Item item1 = null;
		Item item2 = null;
		Item item3 = null;
		Item item4 = null;
		List list = new ArrayList();
		
		item1 = new Item();
		item1.setId("id123");
		item1.setName("홍길동");
		item1.setEmail("aaa@aaa.com");
		list.add(item1);
		
		item2 = new Item();
		item2.setId("id345");
		item2.setName("장금이");
		item2.setEmail("ssa@ba.com");
		list.add(item2);
		
		item3 = new Item();
		item3.setId("id678");
		item3.setName("홍순이");
		item3.setEmail("dwd@1234.com");
		list.add(item3);
		
		item4 = new Item();
		item4.setId("id143");
		item4.setName("똘똘이");
		item4.setEmail("a1@uuu.com");
		list.add(item4);
		
		  
		final Comparator comparator = new Comparator(){
			@Override
			public int compare(Item o1, Item o2) {
				return Collator.getInstance().compare(o1.getId(), o2.getId());
			}
		};
		
		Collections.sort(list, comparator); 
		Item item = null;
		for (int i = 0; i < list.size(); i++) {
			item = list.get(i);
			System.out.println(item.getId()+" - "+item.getName()+" - "+item.getEmail()+" - ");
		}
	}
}