[英]Android XML Reader Reads Once
我只是想制作一個XML Reader,但遇到了一些麻煩。 當我解析XML文件時,它說只有一個標簽,並且只能讀取這個標簽。 但是不止一個。 這是我的代碼:
@Override
protected Void doInBackground(Void... voids) {
try {
URL url = new URL(QuizActivity.fileUrl);
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.parse(new InputSource(url.openStream()));
document.getDocumentElement().normalize();
NodeList sorular = document.getElementsByTagName("sorular");
Log.d("Soru Sayısı", String.valueOf(sorular.getLength()));
for(int i = 0; i < sorular.getLength(); i++){
Node sorularNode = sorular.item(i);
Element sorularElement = (Element) sorularNode;
NodeList siraNodeList = document.getElementsByTagName("sira");
Element siraElement = (Element) siraNodeList.item(i);
NodeList textNodeList = document.getElementsByTagName("text");
Element textElement = (Element) textNodeList.item(i);
NodeList aNodeList = document.getElementsByTagName("a");
Element aElement = (Element) aNodeList.item(i);
NodeList bNodeList = document.getElementsByTagName("b");
Element bElement = (Element) bNodeList.item(i);
NodeList cNodeList = document.getElementsByTagName("c");
Element cElement = (Element) cNodeList.item(i);
NodeList dNodeList = document.getElementsByTagName("d");
Element dElement = (Element) dNodeList.item(i);
NodeList eNodeList = document.getElementsByTagName("e");
Element eElement = (Element) eNodeList.item(i);
NodeList dogruNodeList = document.getElementsByTagName("dogru");
Element dogruElement = (Element) dogruNodeList.item(i);
int sira = Integer.parseInt(siraElement.getChildNodes().item(i).getNodeValue());
SinavActivity.soruText.put(sira, textElement.getChildNodes().item(i).getNodeValue());
SinavActivity.cevap_a.put(sira, aElement.getChildNodes().item(i).getNodeValue());
SinavActivity.cevap_b.put(sira, bElement.getChildNodes().item(i).getNodeValue());
SinavActivity.cevap_c.put(sira, cElement.getChildNodes().item(i).getNodeValue());
SinavActivity.cevap_d.put(sira, dElement.getChildNodes().item(i).getNodeValue());
SinavActivity.cevap_e.put(sira, eElement.getChildNodes().item(i).getNodeValue());
SinavActivity.dogruCevap.put(sira, dogruElement.getChildNodes().item(i).getNodeValue().trim());
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
}
return null;
}
XML檔案:
<?xml version="1.0" encoding="utf-8"?>
<sorular>
<Matematik>
<soru>
<sira>1</sira>
<text>Bir sınıftaki öğrencilerin % 40 ı kız öğrencidir. Kız öğrencilerin % 90 ı, erkek öğrencilerin %80 matematik dersinden başarılıdır. Buna göre, bu sınıfın matematik dersinden başarısı yüzde kaçtır?</text>
<a>84</a>
<b>46</b>
<c>20</c>
<d>12</d>
<e>50</e>
<dogru>A</dogru>
</soru>
<soru>
<sira>2</sira>
<text>A ve B boş olmayan 2 kümedir 2.s(A)=3.s(B)= 5.s(A ∩ B) olduğuna göre s(A-B) en az kaçtır?</text>
<a>8</a>
<b>10</b>
<c>2</c>
<d>9</d>
<e>12</e>
<dogru>D</dogru>
</soru>
</Matematik>
如果我寫NodeList sorular = document.getElementsByTagName("sorular");
它說NodeList = 1
計數NodeList = 1
但是如果我寫NodeList sorular = document.getElementsByTagName("soru");
它說count = 2
但它給了我一個NullPointerException
因為siraElement.getChildNodes().getLength()
將始終返回1
元素,所以當
siraElement.getChildNodes().item(i).getNodeValue() //i=0
因此第一個節點將在0
索引,但是當i=1
然后將沒有Node
在索引1
siraElement.getChildNodes().item(i).getNodeValue() //i=1 error
這樣就可以從0
索引中獲取Always
int sira = Integer.parseInt(siraElement.getChildNodes().item(0).getNodeValue());
// ^^
加上對所有如下所示的值執行相同操作
textElement.getChildNodes().item(0).getNodeValue()
...
dogruElement.getChildNodes().item(0).getNodeValue().trim()
正如Pavneet_Singh所說,我進行了編輯,這是代碼:
@Override
protected Void doInBackground(Void... voids) {
try {
URL url = new URL(QuizActivity.fileUrl);
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.parse(new InputSource(url.openStream()));
Element rootElement = document.getDocumentElement();
NodeList sorular = rootElement.getElementsByTagName("soru");
for(int i = 0; i < sorular.getLength(); i++){
Node soru = sorular.item(i);
Element soruElement = (Element) soru;
String siraText = soruElement.getElementsByTagName("sira").item(0).getTextContent();
String text = soruElement.getElementsByTagName("text").item(0).getTextContent();
String a = soruElement.getElementsByTagName("a").item(0).getTextContent();
String b = soruElement.getElementsByTagName("b").item(0).getTextContent();
String c = soruElement.getElementsByTagName("c").item(0).getTextContent();
String d = soruElement.getElementsByTagName("d").item(0).getTextContent();
String e = soruElement.getElementsByTagName("e").item(0).getTextContent();
String dogru = soruElement.getElementsByTagName("dogru").item(0).getTextContent();
int sira = Integer.parseInt(siraText);
SinavActivity.soruText.put(sira, text);
SinavActivity.cevap_a.put(sira, a);
SinavActivity.cevap_b.put(sira, b);
SinavActivity.cevap_c.put(sira, c);
SinavActivity.cevap_d.put(sira, d);
SinavActivity.cevap_e.put(sira, e);
SinavActivity.dogruCevap.put(sira, dogru);
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
}
return null;
}
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