[英]Can't Parse localhost XML file (NullPointerException)
我試圖在android中創建XML解析器,該xml文件在我的本地主機服務器上。 將URL設置為由localhost編輯的xml文件時出現NullPointerException錯誤,但是當我將xml文件上傳到Dropbox時,解析器正在工作。
錯誤消息:
...
Caused by: java.lang.NullPointerException
at java.io.StringReader.<init>(StringReader.java:47)
at com.learn.dhemas.franchise.XMLParser.getDomElement(XMLParser.java:74)
at com.learn.dhemas.franchise.fragmentLowongan$getDataOrder.doInBackground(fragmentLowongan.java:72)
...
XMLParser,java:
public class XMLParser {
// constructor
public XMLParser() {
}
/**
* Getting XML from URL making HTTP request
* @param url string
* */
public String getXmlFromUrl(String url) {
String xml = null;
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
xml = EntityUtils.toString(httpEntity);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// return XML
return xml;
}
/**
* Getting XML DOM element
* @param XML string
* */
public Document getDomElement(String xml){
Document doc = null;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder db = dbf.newDocumentBuilder();
InputSource is = new InputSource();
is.setCharacterStream(new StringReader(xml));
doc = db.parse(is);
} catch (ParserConfigurationException e) {
Log.e("Error: ", e.getMessage());
return null;
} catch (SAXException e) {
Log.e("Error: ", e.getMessage());
return null;
} catch (IOException e) {
Log.e("Error: ", e.getMessage());
return null;
}
return doc;
}
/** Getting node value
* @param elem element
*/
public final String getElementValue( Node elem ) {
Node child;
if( elem != null){
if (elem.hasChildNodes()){
for( child = elem.getFirstChild(); child != null; child = child.getNextSibling() ){
if( child.getNodeType() == Node.TEXT_NODE ){
return child.getNodeValue();
}
}
}
}
return "";
}
/**
* Getting node value
* @param Element node
* @param key string
* */
public String getValue(Element item, String str) {
NodeList n = item.getElementsByTagName(str);
return this.getElementValue(n.item(0));
}
}
和我活動中的代碼行(片段類) :
...
@Override
protected Void doInBackground(Void... params) {
//Call parser
XMLParser parser = new XMLParser();
//String xml = parser.getXmlFromUrl("https://drive.google.com/uc?export=download&id=0B5bM7szIFKrpY2lPRHdCUUNscjA");
String xml = parser.getXmlFromUrl("http://localhost/GetData.xml");
Document doc = parser.getDomElement(xml);
...
任何幫助將不勝感激
所以問題是當我從應用程序指向localhost時,它將是模擬器上的localhost,而不是Web服務器中的localhost。 為了解決這個問題,我只需要創建一個虛擬本地網絡並為我的計算機提供一個IP地址,以便可以從仿真器訪問該IP。
您可以嘗試在瀏覽器中打開URL: http://localhost/GetData.xml
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