Android 异步任务中的HTTP请求
我有一个解析XML文件的HTTP请求。 我正在尝试从asyntask连接到internet,但一直无法连接 我这样做是通过将代码放在线程中,而不是放在AsycTask中来实现的 我遇到的问题是,HTTP请求是在一个字符串中使用以下代码行调用的:Android 异步任务中的HTTP请求,android,request,android-asynctask,Android,Request,Android Asynctask,我有一个解析XML文件的HTTP请求。 我正在尝试从asyntask连接到internet,但一直无法连接 我这样做是通过将代码放在线程中,而不是放在AsycTask中来实现的 我遇到的问题是,HTTP请求是在一个字符串中使用以下代码行调用的: String xml = parser.getXmlFromUrl(URL); 运行这个 public String getXmlFromUrl(String url) { Thread t= new Thread(){
String xml = parser.getXmlFromUrl(URL);
运行这个
public String getXmlFromUrl(String url) {
Thread t= new Thread(){
public void run() {
xml = null;
try {
Log.i("Log1","Parse");
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("http://api.androidhive.info/music/music.xml");
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();
}
mHandler.post(mUpdateResults);
}
};
t.start();
return xml;
}
final Runnable mUpdateResults =new Runnable (){
public void run(){//2
}
};
正如我所提到的,HTTP请求在一个线程中,但当我试图将其放入AsycTask中时,总是会发现错误。。。我不知道怎么做
我已经参考了AsycTask的文档,并且已经阅读了很多次,我搜索了教程,但是我无法正确构建它
两天后,我开始有点绝望
我为我的工作提供了完整的代码,如果有人能告诉我如何替换AsyncTask线程,我将非常感激
非常感谢您的问候
全部活动:
公共类PrueBasaActivity扩展活动{
静态最终字符串URL=”http://api.androidhive.info/music/music.xml";
//XML节点密钥
静态最终字符串键\u SONG=“SONG”//父节点
静态最终字符串键\u ID=“ID”;
静态最终字符串键\u TITLE=“TITLE”;
静态最终字符串键\u ARTIST=“ARTIST”;
静态最终字符串键\u DURATION=“DURATION”;
静态最终字符串键\u THUMB\u URL=“THUMB\u URL”;
私有数组列表数据;
ArrayList songsList;
列表视图列表;
懒散适配器;
字符串xml;
最终处理程序mHandler=新处理程序();
//建造师
公共void XMLParser(){
}
/**
*Cogiendo el XML de la URL中介HTTP请求
*@param url字符串
* */
公共字符串getXmlFromUrl(字符串url){
线程t=新线程(){
公开募捐{
xml=null;
试一试{
Log.i(“Log1”、“Parse”);
//defaultHttpClient
DefaultHttpClient httpClient=新的DefaultHttpClient();
HttpPost HttpPost=新的HttpPost(“http://api.androidhive.info/music/music.xml");
HttpResponse HttpResponse=httpClient.execute(httpPost);
HttpEntity HttpEntity=httpResponse.getEntity();
xml=EntityUtils.toString(httpEntity);
}捕获(不支持的编码异常e){
e、 printStackTrace();
}捕获(客户端协议例外e){
e、 printStackTrace();
}捕获(IOE异常){
e、 printStackTrace();
}
mHandler.post(mUpdateResults);
}
};
t、 start();
返回xml;
}
最终可运行mUpdateResults=新可运行(){
public void run(){//2
}
};
/*
*@param XML字符串
* */
公共文档getDoElement(字符串xml){
单据单据=空;
DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
试一试{
DocumentBuilder db=dbf.newDocumentBuilder();
InputSource is=新的InputSource();
is.setCharacterStream(新的StringReader(xml));
doc=db.parse(is);
}捕获(ParserConfiguration异常e){
Log.e(“错误:,e.getMessage());
返回null;
}捕获(SAXE异常){
Log.e(“错误:,e.getMessage());
返回null;
}捕获(IOE异常){
Log.e(“错误:,e.getMessage());
返回null;
}
退货单;
}
/*
*@param元素
*/
公共最终字符串getElementValue(节点元素){
节点子节点;
if(elem!=null){
if(elem.hasChildNodes()){
for(child=elem.getFirstChild();child!=null;child=child.getNextSibling()){
if(child.getNodeType()==Node.TEXT\u节点){
返回child.getNodeValue();
}
}
}
}
返回“”;
}
/*
*@param元素节点
*@param键字符串
* */
公共字符串getValue(元素项,字符串str){
NodeList n=item.getElementsByTagName(str);
返回此.getElementValue(n.item(0));
}
@凌驾
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
list=(ListView)findViewById(R.id.list);
songsList=newarraylist();
XMLParser=新的XMLParser();
String xml=parser.getXmlFromUrl(URL);//Cogiendo xml de la URL
Document doc=parser.getdoElement(xml);//Cogiendo DOM de los elementos
NodeList nl=doc.getElementsByTagName(KEY_-SONG);
//循环通过所有歌曲节点
对于(int i=0;ivalue
put(KEY_ID,parser.getValue(e,KEY_ID));
put(KEY_TITLE,parser.getValue(e,KEY_TITLE));
put(KEY_-ARTIST,parser.getValue(e,KEY_-ARTIST));
put(KEY_DURATION,parser.getValue(e,KEY_DURATION));
put(KEY_THUMB_URL,parser.getValue(e,KEY_THUMB_URL));
//将哈希列表添加到ArrayList
歌曲列表。添加(地图);
}
//帕桑多·达托斯·帕萨多斯·德尔·阿雷利斯特
适配器=新的MinAdapter(t
public class PruebasActivity extends Activity {
static final String URL = "http://api.androidhive.info/music/music.xml";
// XML node keys
static final String KEY_SONG = "song"; // parent node
static final String KEY_ID = "id";
static final String KEY_TITLE = "title";
static final String KEY_ARTIST = "artist";
static final String KEY_DURATION = "duration";
static final String KEY_THUMB_URL = "thumb_url";
private ArrayList<HashMap<String, String>> data;
ArrayList<HashMap<String, String>> songsList;
ListView list;
LazyAdapter adapter;
String xml;
final Handler mHandler=new Handler();
// constructor
public void XMLParser() {
}
/**
* Cogiendo el XML de la URL mediante HTTP request
* @param url string
* */
public String getXmlFromUrl(String url) {
Thread t= new Thread(){
public void run() {
xml = null;
try {
Log.i("Log1","Parse");
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("http://api.androidhive.info/music/music.xml");
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();
}
mHandler.post(mUpdateResults);
}
};
t.start();
return xml;
}
final Runnable mUpdateResults =new Runnable (){
public void run(){//2
}
};
/*
* @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;
}
/*
* @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 "";
}
/*
* @param Element node
* @param key string
* */
public String getValue(Element item, String str) {
NodeList n = item.getElementsByTagName(str);
return this.getElementValue(n.item(0));
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
list=(ListView)findViewById(R.id.list);
songsList = new ArrayList<HashMap<String, String>>();
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL); // Cogiendo XML de la URL
Document doc = parser.getDomElement(xml); // Cogiendo DOM de los elementos
NodeList nl = doc.getElementsByTagName(KEY_SONG);
// looping through all song nodes <song>
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_ID, parser.getValue(e, KEY_ID));
map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE));
map.put(KEY_ARTIST, parser.getValue(e, KEY_ARTIST));
map.put(KEY_DURATION, parser.getValue(e, KEY_DURATION));
map.put(KEY_THUMB_URL, parser.getValue(e, KEY_THUMB_URL));
// adding HashList to ArrayList
songsList.add(map);
}
// Pasando datos parseados del adaptador al arrayList
adapter=new MinAdapter(this, songsList);
list.setAdapter(adapter);
}
}
public class XmlTask extends AsyncTask<String, Void, String>{
public String doInBackground(String... urls){
String url = urls[0];
// Place your getXmlFromUrl content here
return xml;
}
public void onPostExecute(String xml){
// Your XML parsing staement here
}
}
new XmlTask().execute("http://yoururl");
public class PruebasActivity extends Activity {
static final String URL = "http://api.androidhive.info/music/music.xml";
// XML node keys
static final String KEY_SONG = "song"; // parent node
static final String KEY_ID = "id";
static final String KEY_TITLE = "title";
static final String KEY_ARTIST = "artist";
static final String KEY_DURATION = "duration";
static final String KEY_THUMB_URL = "thumb_url";
private ArrayList<HashMap<String, String>> data;
ArrayList<HashMap<String, String>> songsList;
ListView list;
LazyAdapter adapter;
String xml;
// constructor
public void XMLParser() {
}
/**
* Cogiendo el XML de la URL mediante HTTP request
* @param url string
* */
public String getXmlFromUrl(String url) {
xml = null;
try {
Log.i("Log1","Parse");
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("http://api.androidhive.info/music/music.xml");
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;
}
/*
* @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;
}
/*
* @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 "";
}
/*
* @param Element node
* @param key string
* */
public String getValue(Element item, String str) {
NodeList n = item.getElementsByTagName(str);
return this.getElementValue(n.item(0));
}
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
list=(ListView)findViewById(R.id.list);
AsyncTask<Void, Void, Void> ast = new AsyncTask<Void, Void, Void>(){
ProgressDialog p;
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
p = new ProgressDialog(EditTextDemoActivity.this);
//write code to start the progress dialog
}
@Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
songsList = new ArrayList<HashMap<String, String>>();
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL); // Cogiendo XML de la URL
Document doc = parser.getDomElement(xml); // Cogiendo DOM de los elementos
NodeList nl = doc.getElementsByTagName(KEY_SONG);
// looping through all song nodes <song>
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_ID, parser.getValue(e, KEY_ID));
map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE));
map.put(KEY_ARTIST, parser.getValue(e, KEY_ARTIST));
map.put(KEY_DURATION, parser.getValue(e, KEY_DURATION));
map.put(KEY_THUMB_URL, parser.getValue(e, KEY_THUMB_URL));
// adding HashList to ArrayList
songsList.add(map);
}
}
@Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
p.dismiss();
adapter=new MinAdapter(this, songsList);
lst.setAdapter(adapter);
}
};
ast.execute();
}
}