java實現近義詞維護

題目要求：
一、近義詞維護
給定接口，設置兩個單詞相互近義。近義詞具有相互傳遞性，如果A和B為近義詞，B和C是近義詞，那么A、B、C都為近義詞。要求提供接口，查詢給定的兩個但是是否是近義詞關系。並且能提供接口清除所有的近義詞關系。
接口說明
/**
 * 設置2個單詞為近義詞
 * @param word1 單詞一
 * @param word2 單詞二
 * @return 0為成功，-1為失敗或其他異常
 */
public int setSynonyms(String word1, String word2)

/**
 *判斷2個單詞是否為近義詞(同一單詞視為近義詞)
 *@param word1 單詞一
 *@param word2 單詞二
 *@return 為近義詞返回true，否則返回false
 */
public boolean isSynonyms(String word1, String word2)

/**
 * 清除單詞之間的近義詞關系
 */
public void clearRelations()

程序如下：首先設定A與B的近義詞關系，再設定B與C的近義詞關系，B與C以及A與C之間都是近義詞關系，所以前兩次為true，當執行clear方法后，map清空，最后一次打印為false

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Scanner;
public class Synonyms {
    private static Boolean isSyn = false;
    static Map<String, String> map = new HashMap<String, String>();
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        String line = scan.nextLine();
        String[] str = line.split(" ");
        System.out.println(setSynonyms(str[0], str[1]));
        String line2 = scan.nextLine();
        String[] str2 = line2.split(" ");
        System.out.println(setSynonyms(str2[0], str2[1]));
        System.out.println(isSynonyms(str2[0], str2[1]));
        System.out.println(isSynonyms(str[0], str2[1]));
        clearRelations();
        System.out.println(isSynonyms(str2[0], str2[1]));
        scan.close();
    }

    public static int setSynonyms(String word1, String word2) {
        map.put(word1, word2);
        map.put(word2, word1);

        if (word1 != "" & word2 != "") {
            // isSyn = true;
            return 0;
        } else
            return -1;

    }

    public static boolean isSynonyms(String word1, String word2) {
        if (!map.containsKey(word1)) {
            isSyn = false;
        }
        if (map.containsKey(word1)) {
            for (String key : map.keySet()) {
                for (int i = 0; i < key.length(); i++) {
                    String value = map.get(word1);
                    String value2 = map.get(value);
                    if (value2.equals(word2)) {
                        isSyn = true;
                    } else if (word2.equals(map.get(word1)))
                        isSyn = true;
                }
            }

        } else
            isSyn = false;
        return isSyn;
    }

    public static void clearRelations() {
        Iterator it = map.keySet().iterator();
        String key = null;
        while (it.hasNext()) {
            key = it.next().toString();
            it.remove();

        }
    }
}