java中string数组转long数组几个例子

方法 一，把数组for 下一个转

String[] yq1012= {"123", "234", "345"};
        Long[] num = new Long[yq1012.length];
        for (int idx = 0; idx < yq1012.length; idx++) {
            num[idx] = Long.parseLong(yq1012[idx]);
        }

方法 二,

public static void main(String[] args) {
        String stringArray[] = { "1", "2", "3", "4", "5", "6", "7", "a" };
        long time1 = System.currentTimeMillis();
        stringToLong(stringArray);
        long time2 = System.currentTimeMillis();
        System.out.println("stringToLong:" + (time2 - time1));
 
        long time3 = System.currentTimeMillis();
        stringToLong_2(stringArray);
        long time4 = System.currentTimeMillis();
        System.out.println("stringToLong_2:" + (time4 - time3));
    }
 
    public static long[] stringToLong(String stringArray[]) {
        if (stringArray == null || stringArray.length < 1) {
            return null;
        }
        long longArray[] = new long[stringArray.length];
        for (int i = 0; i < longArray.length; i++) {
            try {
                longArray[i] = Long.valueOf(stringArray[i]);
            } catch (NumberFormatException e) {
                longArray[i] = 0;
                continue;
            }
        }
        return longArray;
    }
 
    public static long[] stringToLong_2(String stringArray[]) {
        if (stringArray == null)
            return null;
        return (long[]) ConvertUtils.convert(stringArray, long.class);
    }

方法 三

Set<Long> idsSet = new HashSet<Long>();
  //过滤没有详情的id
  for(Entry<Long, UserProfile> entry : userProfileMap.entrySet()){
   UserProfile userProfile = entry.getValue();
   if (userProfile == null) {
    continue;
   }
   idsSet.add(userProfile.getUserId());
  }
  
  Long[] idsLong = idsSet.toArray(new Long[0]);
  int idsLen = idsLong.length;
  long[] idslong = new long[idsLen];
  for(int i = 0; i < idsLen; i++){
   idslong[i] = idsLong[i];
  }