My Problem is I am Using Dom Parsing to parse below xml file but this give me error of NullPointerException.
Any Help Would be Appreciated.
MainActivity.java
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ScrollView mScrView1 = new ScrollView(this);
/** Create a new layout to display the view */
LinearLayout layout = new LinearLayout(this);
layout.setOrientation(1);
/** Create a new textview array to display the results */
TextView id[];
TextView published[];
TextView content[];
TextView title[];
TextView mediacontent[];
TextView mediathumbnail[];
try {
URL url = new URL(
"http://gdata.youtube.com/feeds/api/users/estudiosabiertostv/uploads");
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(new InputSource(url.openStream()));
doc.getDocumentElement().normalize();
NodeList nodeList = doc.getElementsByTagName("entry");
/** Assign textview array length by arraylist size */
id = new TextView[nodeList.getLength()];
published = new TextView[nodeList.getLength()];
content = new TextView[nodeList.getLength()];
title = new TextView[nodeList.getLength()];
mediacontent = new TextView[nodeList.getLength()];
mediathumbnail = new TextView[nodeList.getLength()];
for (int i = 0; i < nodeList.getLength(); i++) {
Node node = nodeList.item(i);
id[i] = new TextView(this);
published[i] = new TextView(this);
content[i] = new TextView(this);
title[i] = new TextView(this);
Element fstElmnt = (Element) node;
NodeList idList = fstElmnt.getElementsByTagName("id");
Element idElement = (Element) idList.item(0);
idList = idElement.getChildNodes();
id[i].setText("Id is = "
+ ((Node) idList.item(0)).getNodeValue());
NodeList publishedList = fstElmnt
.getElementsByTagName("published");
Element publishedElement = (Element) publishedList.item(0);
publishedList = publishedElement.getChildNodes();
published[i].setText("published is = "
+ ((Node) publishedList.item(0)).getNodeValue());
NodeList contentList = fstElmnt.getElementsByTagName("content");
Element contentElement = (Element) contentList.item(0);
contentList = contentElement.getChildNodes();
content[i].setText("content is = "
+ ((Node) contentList.item(0)).getNodeValue());
NodeList titleList = fstElmnt.getElementsByTagName("title");
Element titleElement = (Element) titleList.item(0);
titleList = titleElement.getChildNodes();
title[i].setText("title is = "
+ ((Node) titleList.item(0)).getNodeValue());
NodeList nodeList1 = fstElmnt.getElementsByTagName("media:group");
System.out.println("Size is:- " +nodeList1.getLength());
for (int j = 0; j < nodeList1.getLength(); j++) {
Node node1 = nodeList1.item(j);
mediacontent[j] = new TextView(this);
mediathumbnail[j] = new TextView(this);
Element secondElmnt = (Element) node1;
NodeList mediacontentList = secondElmnt.getElementsByTagName("media:content");
Element mediacontentElement = (Element) mediacontentList.item(0);
mediacontentList = mediacontentElement.getChildNodes();
mediacontent[j].setText("mediacontent is = "
+ ((Node) mediacontentList.item(0)).getNodeValue());
layout.addView(mediacontent[j]);
}
layout.addView(id[i]);
layout.addView(published[i]);
layout.addView(content[i]);
layout.addView(title[i]);
}
} catch (Exception e) {
System.out.println("XML Pasing Excpetion = " + e);
}
/** Set the layout view to display */
mScrView1.addView(layout);
setContentView(mScrView1);
}
}
Try this:
public class DomParserSampleActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ScrollView mScrView1 = new ScrollView(this);
/** Create a new layout to display the view */
LinearLayout layout = new LinearLayout(this);
layout.setOrientation(1);
/** Create a new textview array to display the results */
TextView id[];
TextView published[];
TextView content[];
TextView title[];
TextView mediacontent[];
TextView mediathumbnail[];
try {
URL url = new URL(
"http://gdata.youtube.com/feeds/api/users/estudiosabiertostv/uploads");
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(new InputSource(url.openStream()));
doc.getDocumentElement().normalize();
NodeList nodeList = doc.getElementsByTagName("entry");
/** Assign textview array length by arraylist size */
id = new TextView[nodeList.getLength()];
published = new TextView[nodeList.getLength()];
content = new TextView[nodeList.getLength()];
title = new TextView[nodeList.getLength()];
mediacontent = new TextView[nodeList.getLength()];
mediathumbnail = new TextView[nodeList.getLength()];
for (int i = 0; i < nodeList.getLength(); i++) {
Node node = nodeList.item(i);
id[i] = new TextView(this);
published[i] = new TextView(this);
content[i] = new TextView(this);
title[i] = new TextView(this);
Element fstElmnt = (Element) node;
NodeList idList = fstElmnt.getElementsByTagName("id");
Element idElement = (Element) idList.item(0);
idList = idElement.getChildNodes();
id[i].setText("Id is = "
+ ((Node) idList.item(0)).getNodeValue());
Log.v("TAG","id: "+idList.item(0).getNodeValue());
NodeList publishedList = fstElmnt
.getElementsByTagName("published");
Element publishedElement = (Element) publishedList.item(0);
publishedList = publishedElement.getChildNodes();
published[i].setText("published is = "
+ ((Node) publishedList.item(0)).getNodeValue());
Log.v("TAG","published: "+publishedList.item(0).getNodeValue());
NodeList contentList = fstElmnt.getElementsByTagName("content");
Element contentElement = (Element) contentList.item(0);
contentList = contentElement.getChildNodes();
content[i].setText("content is = "
+ ((Node) contentList.item(0)).getNodeValue());
Log.v("TAG","content: "+contentList.item(0).getNodeValue());
NodeList titleList = fstElmnt.getElementsByTagName("title");
Element titleElement = (Element) titleList.item(0);
titleList = titleElement.getChildNodes();
title[i].setText("title is = "
+ ((Node) titleList.item(0)).getNodeValue());
Log.v("TAG","titulo: "+titleList.item(0).getNodeValue());
NodeList nodeList1 = fstElmnt
.getElementsByTagName("media:group");
for (int j = 0; j < nodeList1.getLength(); j++) {
Node node1 = nodeList1.item(j);
mediacontent[j] = new TextView(this);
mediathumbnail[j] = new TextView(this);
Element secondElmnt = (Element) node1;
NodeList mediacontentList = secondElmnt
.getElementsByTagName("media:content");
Element mediacontentElement = (Element) mediacontentList
.item(0);
mediacontent[j].setText("mediacontent url is = "
+ mediacontentElement.getAttribute("url"));
Log.v("TAG","MEDIACONTENT: "+mediacontentElement.getAttribute("url"));
NodeList mediathumbnailList = secondElmnt
.getElementsByTagName("media:thumbnail");
Element mediathumbnailElement = (Element) mediathumbnailList
.item(0);
mediathumbnail[j].setText("mediathumbnail url is = "
+ mediathumbnailElement.getAttribute("url"));
Log.v("TAG","MEDIATHUMBNAIL: "+mediathumbnailElement.getAttribute("url"));
layout.addView(mediacontent[j]);
layout.addView(mediathumbnail[j]);
}
layout.addView(id[i]);
layout.addView(published[i]);
layout.addView(content[i]);
layout.addView(title[i]);
}
} catch (Exception e) {
e.printStackTrace();
}
/** Set the layout view to display */
mScrView1.addView(layout);
setContentView(mScrView1);
}
}
Do not forget to do so within a thread or failing that, use these lines After the onCreate()
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
try this
create a new class XMLParser
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.io.StringWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import android.util.Log;
public class XMLParser {
public String getXmlFromUrl(String urll) {
String response = "";
try {
URLConnection conn = null;
InputStream inputStream = null;
URL url = new URL(urll);
conn = url.openConnection();
conn.setConnectTimeout(10000);
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setRequestMethod("GET");
httpConn.setConnectTimeout(10000);
httpConn.connect();
if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
inputStream = httpConn.getInputStream();
}
BufferedReader in = new BufferedReader(new InputStreamReader(inputStream));
StringWriter writer=new StringWriter();
String line="";
while ( null!=(line=in.readLine())){
writer.write(line);
}
response =writer.toString();
}
catch (Exception e) {
// TODO: handle exception
}
return response;
}
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 DOM
return doc;
}
public String getValue(Element item, String str) {
NodeList n = item.getElementsByTagName(str);
return this.getElementValue(n.item(0));
}
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 || child.getNodeType() == Node.CDATA_SECTION_NODE) {
return child.getNodeValue();
}
}
}
}
return "";
}
}
your xml for example
<results>
<result>
<title>title1</title>
<description>description1</description>
<lien>lien1</lien>
</result>
<result>
<title>title2</title>
<description>description2</description>
<lien>lien2</lien>
</result>
</results>
and, to use it in your Activity
final String KEY_ITEM = "result"; // parent node
final String KEY_TITLE = "title";
final String KEY_DESC = "description";
final String KEY_LINK = "lien";
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl("YourXmlURL"); // getting XML
Document doc = parser.getDomElement(xml); // getting DOM element
NodeList elements = doc.getElementsByTagName(KEY_ITEM);
List<String> title= new ArrayList<String>(); // or other type
List<String> descp= new ArrayList<String>();
Element e;
for (int i = 0; i < elements.getLength(); i++) {
e = (Element) elements.item(i);
title.add(parser.getValue(e, KEY_TITLE));
descp.add(parser.getValue(e,KEY_DESC));
}
来源：https://stackoverflow.com/questions/12106287/how-to-parse-xml-file-using-dom-parsing