static int indexOf(char[] source, int sourceOffset, int sourceCount,             char[] target, int targetOffset, int targetCount,             int fromIndex) {         if (fromIndex >= sourceCount) {             return (targetCount == 0 ? sourceCount : -1);         }         if (fromIndex < 0) {             fromIndex = 0;         }         if (targetCount == 0) {             return fromIndex;         }          char first = target[targetOffset];         int max = sourceOffset + (sourceCount - targetCount);          for (int i = sourceOffset + fromIndex; i <= max; i++) {             /* Look for first character. */             if (source[i] != first) {                 while (++i <= max && source[i] != first);             }              /* Found first character, now look at the rest of v2 */             if (i <= max) {                 int j = i + 1;                 int end = j + targetCount - 1;                 for (int k = targetOffset + 1; j < end && source[j]                         == target[k]; j++, k++);                  if (j == end) {                     /* Found whole string. */                     return i - sourceOffset;                 }             }         }         return -1;     } 

if里面为何不直接使用continue?