检查表数据-Jsoup

Question

Is there a way to check if a table has a certain row using jsoup?

I am getting an java.lang.IndexOutOfBoundsException: Invalid location 1, size is 1 exception, my code for getting the info out of the table is:

  docTide = Jsoup.connect("http://www.mhpa.co.uk/search-tide-times/").timeout(600000).get();
  Elements tideTimeOdd = docTide.select("div.tide_row.odd div:eq(0)");
  Elements tideTimeEven = docTide.select("div.tide_row.even div:eq(0)");
  Elements tideHightOdd = docTide.select("div.tide_row.odd div:eq(2)");
  Elements tideHightEven = docTide.select("div.tide_row.even div:eq(2)");
  Element firstTideTime = tideTimeOdd.first();
  Element secondTideTime = tideTimeEven.first();
  Element thirdTideTime = tideTimeOdd.get(1);
  Element fourthTideTime = tideTimeEven.get(1);

The exception is occurring because sometime the table only has 3 rows instead of 4, in this order; odd even odd even

it is the last 'even' row that is causing the problem.

  <div class="tide_row odd"> 
  <div class="time">00:57</div>
  <div class="height_m">4.9</div>
  <div class="height_f">16,1</div>
  <div class="range_m">1.9</div>
  <div class="range_f">6,3</div>
  </div>
  <div class="tide_row even">
  <div class="time">07:23</div>
  <div class="height_m">2.9</div>
  <div class="height_f">9,6</div>
  <div class="range_m">2</div>
  <div class="range_f">6,7</div>
  </div>
  <div class="tide_row odd">
  <div class="time">13:46</div>
  <div class="height_m">5.1</div>
  <div class="height_f">16,9</div>
  <div class="range_m">2.2</div>
  <div class="range_f">7,3</div>
  </div>
  <div class="tide_row even">
  <div class="time">20:23</div>
  <div class="height_m">2.8</div>
  <div class="height_f">9,2</div>
  <div class="range_m">2.3</div>
  <div class="range_f">7,7</div>
  </div>

Answer 1

To simply check the size of the Elements object, use the size() method to determine if it exists or not.

To check for a certain Element use the contains() method.

You might also consider using a loop to iterate over all the Element objects in your Elements collection.

---

if(tideTimeEven.size() > 1)
    //Do something

Answer 2

You could do

if (tideTimeEven.size() > 1) {
    Element fourthTideTime = tideTimeEven.get(1);
}