java is determined whether the set of two, and obtains the same intersection, union, difference

You need to determine whether the set of two operations when using the same, all the tools to provide a method using a characteristic (unique element) set collection:

private Map<String,Set<Integer>> getCategoryApiId(Set<Integer> oldAuthSet , Set<Integer> newAuthSet){
        Map<String,Set<Integer>> categoryApiId = new HashMap();
        if (oldAuthSet!=null&&newAuthSet!=null){
            //首先判断两个集合是否一致
            if (oldAuthSet.size()==newAuthSet.size()){
                Set<Integer> tempSet = new HashSet<Integer>();
                tempSet.addAll(oldAuthSet);
                tempSet.addAll(newAuthSet);
                if (tempSet.size()==oldAuthSet.size()){
                    categoryApiId = null ; // not increase the number of api 
                    logger.info ( "not to add and delete api" ); 
                } the else {
                     // . 1: intersection; 2: ab set difference; 3: Set and 
                    Set <Integer> apiSet1 getApiSet = (oldAuthSet, newAuthSet,. 1 ); 
                    the Set <Integer> = deleteAuthSet getApiSet (oldAuthSet, apiSet1, 2 ); 
                    the Set <Integer> = insertAuthSet getApiSet (newAuthSet, oldAuthSet, 2); // Get new apiId 
                    logger.info ( "remove the API:" + deleteAuthSet); 
                    logger.info ("The new API:" + insertAuthSet); 
                    categoryApiId.put ( "insertApi" 
                logger.info ( "Deleted api: "+, insertAuthSet); 
                    categoryApiId.put ( "datele" , deleteAuthSet); 
                } 
            } the else {
                 // . 1: intersection; 2: ab set difference; 3: ba set difference; 4: Set and 
                Set <Integer> apiSet1 = getApiSet (oldAuthSet, newAuthSet, 1 ); 
                the Set <Integer> deleteAuthSet = getApiSet (oldAuthSet, apiSet1, 2); // get apiId remove 
                the Set <Integer> insertAuthSet = getApiSet (newAuthSet, oldAuthSet, 2); // get the new apiId 
                categoryApiId.put (deleteAuthSet); 
                logger.info ( "new API:" + insertAuthSet); "insertApi" , insertAuthSet); 
                categoryApiId.put ( "datele" , deleteAuthSet); 
            } 
        } the else {
             IF (oldAuthSet == null && newAuthSet =! null ) {     // all new API 
                logger.info ( "the first time the new authorization API" ); 
                categoryApiId.put ( "insertApi" , newAuthSet); 
            } the else  IF ! (oldAuthSet = null &&newAuthSet == null ) {   // unmodified api user authorization data 
                logger.info (" no new authorization api " ); 
                categoryApiId.put ( "datele" , oldAuthSet); 
            } the else  IF (oldAuthSet == null && newAuthSet == null ) { 
                logger.info ( "new authorization and authorized api api is empty " ); 
                categoryApiId = null ; 
            } 
        } 
        return categoryApiId; 
    } 

Private the Set <Integer> getApiSet (the Set <Integer> oldAuthSet, the Set <Integer> newAuthSet, int In Flag) { 
        the Set <Integer> = Result new new HashSet <Integer>();
        if(flag==1){ //求交集
            result.clear();
            result.addAll(oldAuthSet);
            result.retainAll(newAuthSet);
        }else if(flag==2){ //求差集
            result.clear();
            result.addAll(oldAuthSet);
            result.removeAll(newAuthSet);
        } else if (flag==3){ //求并集
            result.clear();
            result.addAll(oldAuthSet);
            result.addAll(newAuthSet);
        }
        return result;
    }