无法启动的活动ComponentInfo { [英] Unable to start activity ComponentInfo{
问题描述
我有以下错误：
12-05 20:35:31.005: E/AndroidRuntime(1084): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.helplawyer/com.example.helplawyer.AndroidXMLParsingActivity}: android.os.NetworkOnMainThreadException
在XML清单我加入＆LT;使用-权限的Android：名称=android.permission.INTERNET对/＆GT;
这是我的主类
package com.example.helplawyer;
public class AndroidXMLParsingActivity extends ListActivity {
// All static variables
static final String URL = "http://www.consultant.ru/rss/hotdocs.xml";
// XML node keys
static final String KEY_ITEM = "item"; // parent node
static final String KEY_TITLE = "title";
static final String KEY_DATE = "pubDate";
static final String KEY_LINK = "link";
static final String KEY_DESC = "description";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mainxml);
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_LINK, parser.getValue(e, KEY_LINK));
map.put(KEY_DATE, parser.getValue(e, KEY_DATE));
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, KEY_DATE, KEY_LINK }, new int[] {
R.id.name, R.id.description, R.id.cost, R.id.link });
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String cost = ((TextView) view.findViewById(R.id.cost)).getText().toString();
String link = ((TextView) view.findViewById(R.id.link)).getText().toString();
String description = ((TextView) view.findViewById(R.id.description)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
in.putExtra(KEY_TITLE, name);
in.putExtra(KEY_DATE, cost);
in.putExtra(KEY_LINK, link);
in.putExtra(KEY_DESC, description);
startActivity(in);
}
});
}
}
XMLParser的
XMLParser
package com.example.helplawyer;
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));
}
}
我读<一href="http://stackoverflow.com/questions/8559381/e-androidruntime3306-java-lang-runtimeexception-unable-to-start-activity-com">stackoverflow我需要使用新主题（新的Runnable（）{
但我不知道如何重写我的code，我的应用程序工作良好。
请帮我看看我的问题！
谢谢
I read on stackoverflow that I need to use new Thread(new Runnable() {
but I don't understand how to rewrite my code that my app works good.
Please, help me with my problem!
Thank you
推荐答案
从Android的文档。
当应用程序试图执行时引发的异常 联网运行其主线程。
The exception that is thrown when an application attempts to perform a networking operation on its main thread.
这是只抛出针对蜂窝SDK或应用程序 更高。针对早期SDK版本的应用程序可以做 网络对他们的主事件循环线程，但它的高度 灰心。查看文档设计的响应。
This is only thrown for applications targeting the Honeycomb SDK or higher. Applications targeting earlier SDK versions are allowed to do networking on their main event loop threads, but it's heavily discouraged. See the document Designing for Responsiveness.
另请参见StrictMode。
Also see StrictMode.
看这里在后台运行此操作的例子（查找的如何避免ANRS 的）
Look here for examples of running this operation in the background (Find "How to Avoid ANRs")
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