我正在尝试解析存储在列表视图中的XML。这是我的代码：
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();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
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));
}
}
AndroidXMLParsingActivity.java
public class AndroidXMLParsingActivity extends ListActivity {
// All static variables
static final String URL = "http://www.findyourfate.com/rss/dailyhoroscope-feed.asp?sign=Capricorn";
// XML node keys
static final String KEY_ITEM = "item"; // parent node
static final String KEY_TITLE = "title";
static final String KEY_DESC = "description";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL); // getting XML
Document doc = parser.getDomElement(xml); // getting DOM element
NodeList nl = doc.getElementsByTagName(KEY_ITEM);
// looping through all item nodes <item>
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
// adding each child node to HashMap key => value
map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE));
map.put(KEY_DESC, parser.getValue(e, KEY_DESC));
// adding HashList to ArrayList
menuItems.add(map);
}
// Adding menuItems to ListView
ListAdapter adapter = new SimpleAdapter(this, menuItems,
R.layout.list_item,
new String[] { KEY_TITLE, KEY_DESC}, new int[] {
R.id.name, R.id.desciption});
setListAdapter(adapter);
}
}
现在我想将此解析后的值存储在字符串中，而不是此列表中。但是当我尝试 parser.getValue（e，KEY_DESC））; 我不知道这里的元素是什么。 如果我想将KEY_DESC设置为textview t1的文本，我该怎么办？
修改
我试过这样做，但它显示了NullPointer异常。这是我试过的：
XMLParserActivity.class：
public class XMLParserActivity extends Fragment {
Button b1;
TextView t1;
EditText e1;
String sunsign;
static final String URL = "http://www.findyourfate.com/rss/dailyhoroscope-feed.asp?sign=Capricorn";
// XML node keys
static final String KEY_ITEM = "item"; // parent node
static final String KEY_TITLE = "title";
static final String KEY_DESC = "description";
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.horoscope,
container, false);
e1 = (EditText) rootView.findViewById(R.id.editText1);
b1 = (Button) rootView.findViewById(R.id.button1);
t1 = (TextView) rootView.findViewById(R.id.textView1);
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
sunsign = e1.getText().toString();
ShowResult(sunsign);
// Toast.makeText(getActivity(), ""+fullname,
// Toast.LENGTH_SHORT).show();
}
});
return rootView;
}
private void ShowResult(String fullname) {
// TODO Auto-generated method stub
new Thread(new Runnable(){
public void run()
{
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL); // getting XML
Document doc = parser.getDomElement(xml); // getting DOM element
NodeList nl = doc.getElementsByTagName(KEY_ITEM);
Element e = (Element) nl.item(0);
String desc = parser.getValue(e, KEY_DESC);
t1.setText(desc);
}
}).start();
DoStyling();
}
public void DoStyling() {
// TODO Auto-generated method stub
t1.setVisibility(View.VISIBLE);
//Toast.makeText(getActivity(), ""+lovenumarray, Toast.LENGTH_SHORT).show();
}
}
logcat的：
10-14 18:44:35.712: E/AndroidRuntime(17084): FATAL EXCEPTION: main
10-14 18:44:35.712: E/AndroidRuntime(17084): java.lang.NullPointerException
10-14 18:44:35.712: E/AndroidRuntime(17084): at tech.know.merge.calove.HoroscopeFragment.DoStyling(HoroscopeFragment.java:82)
10-14 18:44:35.712: E/AndroidRuntime(17084): at tech.know.merge.calove.HoroscopeFragment.ShowResult(HoroscopeFragment.java:76)
10-14 18:44:35.712: E/AndroidRuntime(17084): at tech.know.merge.calove.HoroscopeFragment.access$0(HoroscopeFragment.java:59)
10-14 18:44:35.712: E/AndroidRuntime(17084): at tech.know.merge.calove.HoroscopeFragment$1.onClick(HoroscopeFragment.java:49)
10-14 18:44:35.712: E/AndroidRuntime(17084): at android.view.View.performClick(View.java:4211)
10-14 18:44:35.712: E/AndroidRuntime(17084): at android.view.View$PerformClick.run(View.java:17446)
10-14 18:44:35.712: E/AndroidRuntime(17084): at android.os.Handler.handleCallback(Handler.java:725)
10-14 18:44:35.712: E/AndroidRuntime(17084): at android.os.Handler.dispatchMessage(Handler.java:92)
10-14 18:44:35.712: E/AndroidRuntime(17084): at android.os.Looper.loop(Looper.java:153)
10-14 18:44:35.712: E/AndroidRuntime(17084): at android.app.ActivityThread.main(ActivityThread.java:5297)
10-14 18:44:35.712: E/AndroidRuntime(17084): at java.lang.reflect.Method.invokeNative(Native Method)
10-14 18:44:35.712: E/AndroidRuntime(17084): at java.lang.reflect.Method.invoke(Method.java:511)
10-14 18:44:35.712: E/AndroidRuntime(17084): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
10-14 18:44:35.712: E/AndroidRuntime(17084): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
10-14 18:44:35.712: E/AndroidRuntime(17084): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：4)
Hello Here您可以使用DOM Parser解决您的问题
class getData extends AsyncTask<Void, Void, String> {
private ProgressDialog mProgress;
private String responseString;
private String result;
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
mProgress = new ProgressDialog(DOMXMLParsingActivity.this);
mProgress.setMessage("Loading");
mProgress.setProgressStyle(ProgressDialog.STYLE_SPINNER);
mProgress.setCancelable(false);
mProgress.show();
}
@Override
protected String doInBackground(Void... unsued) {
try {
HttpPost httpPost = new HttpPost(
"http://www.findyourfate.com/rss/dailyhoroscope-feed.asp?sign=Capricorn");
httpPost.addHeader("Accept", "application/xml");
httpPost.addHeader("Content-Type", "application/xml");
HttpClient httpclient = new DefaultHttpClient();
HttpResponse httpResponse = (HttpResponse) httpclient
.execute(httpPost);
if (httpResponse.getStatusLine().getStatusCode() == 200) {
responseString = EntityUtils.toString(httpResponse
.getEntity());
System.out.println("pankaj " + responseString);
result = "true";
}
} catch (Exception e) {
e.printStackTrace();
System.out.println("error" + e);
result = "false";
}
return result;
}
@Override
protected void onPostExecute(String sResponse) {
mProgress.dismiss();
if (result.equals("true")) {
XMLDOMParser parser = new XMLDOMParser();
ArrayList<Data> datas = new ArrayList<Data>();
InputStream stream = new ByteArrayInputStream(
responseString.getBytes());
Document doc = parser.getDocument(stream);
NodeList nodeList = doc.getElementsByTagName("item");
for (int i = 0; i < nodeList.getLength(); i++) {
Element e = (Element) nodeList.item(i);
Data data = new Data();
data.setName(parser.getValue(e, "title"));
data.setUsername(parser.getValue(e, "description"));
datas.add(data);
System.out.println("pankaj " + parser.getValue(e, "title")
+ " " + parser.getValue(e, "description") + " "
+ parser.getValue(e, "link"));
}
listView.setAdapter(new CustomListAdapter(
DOMXMLParsingActivity.this, datas));
} else {
}
}
}
package com.example.demowork;
import java.io.IOException;
import java.io.InputStream;
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 XMLDOMParser {
public Document getDocument(InputStream inputStream) {
Document document = null;
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder db = factory.newDocumentBuilder();
InputSource inputSource = new InputSource(inputStream);
document = db.parse(inputSource);
} 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 document;
}
public String getValue(Element item, String name) {
NodeList nodes = item.getElementsByTagName(name);
return this.getTextNodeValue(nodes.item(0));
}
private final String getTextNodeValue(Node node) {
Node child;
if (node != null) {
if (node.hasChildNodes()) {
child = node.getFirstChild();
while (child != null) {
if (child.getNodeType() == Node.TEXT_NODE) {
return child.getNodeValue();
}
child = child.getNextSibling();
}
}
}
return "";
}
}