获取具有相同名称的Android的下一个Jsoup元素

Question

I'm retreving elements in Android with Jsoup. I need to get the next eta element from this code. I'm not sure how to. I'm retreiving the xml from: http://lapi.transitchicago.com/api/1.0/ttarrivals.aspx?key=201412abc85d49b2b83f907f9e329eaa&mapid=40380 . Someone has brought up using elem.iterator(), but I'm not sure how to put this in my code (this is the website for it) http://www.jsoup.org/apidocs/org/jsoup/select/Elements.html#iterator() My code is below.

TestStation.java

public class TestStation extends Activity {
String URL = "http://lapi.transitchicago.com/api/1.0/ttarrivals.aspx?key=201412abc85d49b2b83f907f9e329eaa&mapid=40380";
@SuppressWarnings("deprecation")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
        setContentView(R.layout.test_station);
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy); 



Document doc = null;

TextView tv = (TextView) findViewById(R.id.tv);
TextView tv1 = (TextView) findViewById(R.id.tv1);
TextView tv2 = (TextView) findViewById(R.id.tv2);
TextView tv3 = (TextView) findViewById(R.id.tv3);
TextView tv4 = (TextView) findViewById(R.id.tv4);
TextView tv5 = (TextView) findViewById(R.id.tv5);

try {
    doc = Jsoup.connect(URL).userAgent("Mozilla/5.0 (Macintosh; U; Intel Mac OS X; de-de) AppleWebKit/523.10.3 (KHTML, like Gecko) Version/3.0.4 Safari/523.10").get();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
    Iterator<Element> iterator = elem.iterator();
while(iterator.hasNext())
{ Element div = iterator.next();

Elements arrT = div.select("arrT");
Elements prdt = div.select("prdt");
Elements staNm = div.select("staNm");
String StaNm = staNm.text();
tv1.setText(String.valueOf (StaNm));


while(iterator.hasNext())
{ Element div1 = iterator.next();

Elements arrT1 = div1.select("arrT");
Elements prdt1 = div1.select("prdt");
Elements staNm1 = div1.select("staNm");
String StaNm1 = staNm1.text();
tv2.setText(String.valueOf (StaNm1));



try {

    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd HH:mm:ss");
    Date date1 = sdf.parse(arrT.text());
    Date date2 = sdf.parse(prdt.text());
    Date date3 = sdf.parse(arrT1.text());
    Date date4 = sdf.parse(prdt1.text());

    long dateDiff = (date1.getTime() - date2.getTime())>0 ? (date1.getTime() - date2.getTime()) :(date2.getTime() - date1.getTime());
    long dateDiff1 = (date3.getTime() - date4.getTime())>0 ? (date3.getTime() - date4.getTime()) :(date4.getTime() - date3.getTime());
    SimpleDateFormat sdf1 = new SimpleDateFormat("mm:00");
    String dateDif = sdf1.format(dateDiff);
    String dateDif1 = sdf1.format(dateDiff1);
    tv.setText(String.valueOf (dateDif));
    tv3.setText(String.valueOf (dateDif1));


    }

catch (ParseException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();



 }

}
}
}

I'm now getting LogCat errors, and it says that it has stopped working:

09-26 20:34:50.456: E/AndroidRuntime(22691): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dev.chicagotraintracker/com.dev.chicagotraintracker.TestStation}: java.lang.NullPointerException
09-26 20:34:50.456: E/AndroidRuntime(22691):    at com.dev.chicagotraintracker.TestStation.onCreate(TestStation.java:57)

With my code, I get two elements, but they are the exact same. I get the same numbers for dateDiff and dateDiff1. How can I get the next eta element with the same name? Thank you for your help.

Answer 1

So if I understood correctly, this might help you:

Elements elem = doc.select("eta");
Iterator<Element> iterator = elem.iterator();
while(iterator.hasNext()) {
    Element etaElement = iterator.next();
    Element arrT = etaElement.select("arrT");    
    Element prdt = etaElement.select("prdt");
    //  1. parse the arrT value
    //  2. parse the prdt value
    //  3. subtract them.
}

Like this you will be able to individually handle each entry. Note the the div.select is being used for each eta element and not from the whole document, as your code was doing.