比较两个HashMap是否相同

比较两个HashMap是否相同， 刚看到一个面试题， 就写了下， 如有错误， 还请看到的指正啊. 效果应该是使用entrySet较快

 

import java.util.HashMap;
import java.util.Map;


public class Test {

	public static boolean compareMapByKeySet(Map<String,String> map1,Map<String,String> map2){

		if(map1.size()!=map2.size()){  
			return false;
		}
		
		
		String tmp1;
		String tmp2;
		boolean b=false;
		
		for(String key:map1.keySet()){
			if(map2.containsKey(key)){
				tmp1=map1.get(key);
				tmp2=map2.get(key);
				
				if(null!=tmp1 && null!=tmp1){ 
					
					if(tmp1.equals(tmp2)){
						b=true;
						continue;
					}else{
						b=false;
						break;
					}
					
				}else if(null==tmp1 && null==tmp2){	 
					b=true;
					continue;
				}else{
					b=false;
					break;
				}
				
				
			}else{
				b=false;
				break;
			}
			
		}

		return b;
	}
	
	
	
	
	public static boolean compareMapByEntrySet(Map<String,String> map1,Map<String,String> map2){

		if(map1.size()!=map2.size()){  
			return false;
		}
		
		String tmp1;
		String tmp2;
		boolean b=false;
		
		for(Map.Entry<String, String> entry:map1.entrySet()){
			if(map2.containsKey(entry.getKey())){
				tmp1=entry.getValue();
				tmp2=map2.get(entry.getKey());
				
				if(null!=tmp1 && null!=tmp1){ 	//都不为null
					if(tmp1.equals(tmp2)){
						b=true;
						continue;
					}else{
						b=false;
						break;
					}
				}else if(null==tmp1 && null==tmp2){	 //都为null
					b=true;
					continue;
				}else{
					b=false;
					break;
				}
			}else{
				b=false;
				break;
			}
		}
		

		return b;
	}
	
	
	public static void main(String[] args) {
		
		Map<String,String> hs1=new HashMap<String,String>();
		Map<String,String> hs2=new HashMap<String,String>();
		
		hs1.put("001key","001value");
		hs1.put("002key","002value");
		hs1.put("003key","003value");
		hs1.put("004key","004value");
		hs1.put("005key","005value");
		hs1.put("006key","006value");
		hs1.put("007key","007value");
		
		hs2.put("001key","001value");
		hs2.put("002key","002value");
		hs2.put("006key","006value");
		hs2.put("005key","005value");
		hs2.put("007key","007value");
		hs2.put("004key",null);
		hs2.put("003key","003value");
		
		
		long st1=System.currentTimeMillis();
		boolean b1=compareMapByKeySet(hs1, hs2);
		long et1=System.currentTimeMillis();
		
		System.out.println("使用keySet方法比较的结果是: "+b1+", 耗时是: "+(et1-st1));
		
		long st2=System.currentTimeMillis();
		boolean b2=compareMapByEntrySet(hs1, hs2);
		long et2=System.currentTimeMillis();
		
		System.out.println("使用entrySet方法比较的结果是: "+b2+", 耗时是: "+(et2-st2));
		
		
/*		
		long starttime1=System.currentTimeMillis();
		for(String key:hs1.keySet()){
			System.out.println(hs1.get(key));
		}
		long endtime1=System.currentTimeMillis();
		
		System.out.println(endtime1-starttime1);
		
		long starttime2=System.currentTimeMillis();
		for(Map.Entry<String, String> entry:hs1.entrySet()){
			System.out.println(entry.getValue());
		}
		long endtime2=System.currentTimeMillis();
		
		System.out.println(endtime2-starttime2);
		*/
	}

}