通过不同的字符串键比较Hashmaps

Question

i have two HashMaps and want compare it as fast as possible but the problem is, the String of mapA consist of two words connected with a space. The String of mapB is only one word.

I dont want to count the occurences, that is already done, i want to compare the two diferent Strings

mapA: 
key: hello world, value: 10 
key: earth hi, value: 20

mapB:  
key: hello, value: 5  
key: world, value: 15
key: earth, value: 25
key: hi,    value: 35

the first key of mapA should find key "hello" and key "world" from mapB

what i trying to do is parsing a long Text to find Co occurences and set a value how often they occur related to all words.

my first try:

for(String entry : mapA.keySet())
    {
String key = (String) entry;
      Integer mapAvalue = (Integer) mapA.get(entry);
      Integer tokenVal1=0, tokenVal2=0;
      String  token1=key.substring(0, key.indexOf(" "));
      String      token2=key.substring(key.indexOf(" "),key.length()).trim();
         for( String mapBentry : mapb.keySet())
        {
            String tokenkey = mapBentry;
            if(tokenkey.equals(token1)){
                tokenVal1=(Integer)tokens.get(tokenentry);
            }
            if(tokenkey.equals(token2)){
                tokenVal2=(Integer)tokens.get(tokenentry);
            }
            if(token1!=null && token2!=null && tokenVal1>1000 && tokenVal2>1000 ){

                **procedurecall(mapAvalue, token1, token2, tokenVal1, tokenVal2);**


             }
        }


    }

Answer 1

You shouldn't iterate over a HashMap (O(n)) if you are just trying to find a particular key, that's what the HashMap lookup (O(1)) is used for. So eliminate your inner loop.

Also you can eliminate a few unnecessary variables in your code (eg key , tokenkey ). You also don't need a third tokens map, you can put the token values in mapb .

for(String entry : mapA.keySet())
{
  Integer mapAvalue = (Integer) mapA.get(entry);
  String  token1=entry.substring(0, entry.indexOf(" "));
  String  token2=entry.substring(entry.indexOf(" "),entry.length()).trim();

  if(mapb.containsKey(token1) && mapb.containskey(token2))
  {
       // look up the tokens:
       Integer tokenVal1=(Integer)mapb.get(token1);
       Integer tokenVal2=(Integer)mapb.get(token2);

       if(tokenVal1>1000 && tokenVal2>1000)
       {
            **procedurecall(mapAvalue, token1, token2, tokenVal1, tokenVal2);**
       }
  }