[英]Android Xml data parsing
我正在尝试解析XML并将其显示到列表视图中,但是在运行该应用程序后,列表显示没有任何反应,但没有XML数据。 我不知道我是否想念一些东西可以帮助我。
MainActivity类
public class MainActivity extends ListActivity {
// All static variables
static final String URL = "http://api.androidhive.info/pizza/?format=xml";
// XML node keys
static final String KEY_ITEM = "item"; // parent node
static final String KEY_ID = "id";
static final String KEY_NAME = "name";
static final String KEY_COST = "cost";
static final String KEY_DESC = "description";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
ListView myList=(ListView)findViewById(android.R.id.list);
ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();
XMLParser parser = new XMLParser();
String xml = null; // getting XML
try {
xml = parser.getXmlFormUrl(URL);
} catch (IOException e) {
e.printStackTrace();
}
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_ID, parser.getValue(e, KEY_ID));
map.put(KEY_NAME, parser.getValue(e, KEY_NAME));
map.put(KEY_COST, "Rs." + parser.getValue(e, KEY_COST));
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.activity_main,
new String[] { KEY_NAME, KEY_DESC, KEY_COST }, new int[] {
R.id.name, R.id.desciption, R.id.cost });
setListAdapter(adapter);
// selecting single ListView item
}
}
XmlParser类
public class XMLParser {
String result;
public String getXmlFormUrl(String link) throws IOException{
URL url=new URL(link.toString());
HttpURLConnection UrlConnection= (HttpURLConnection) url.openConnection();
int status=UrlConnection.getResponseCode();
if(status==200){
InputStream inputStream=UrlConnection.getInputStream();
BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(inputStream,"UTF8"));
StringBuilder stringBuilder= new StringBuilder();
String line;
while ((line=bufferedReader.readLine())!=null){
stringBuilder.append((line+"\n"));
}
result=stringBuilder.toString();
inputStream.close();
}
return result;
}
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 ){
return child.getNodeValue();
}
}
}
}
return "";
}
}
ActivityMain.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="android.prgguru.com.xmlparsingg.MainActivity"> <ListView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@android:id/list" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:layout_marginTop="73dp" /> </RelativeLayout>
在此行之后,我认为该列表应与XML数据一起显示,但没有任何反应
myList.setAdapter(adapter);
ids.xml
<?xml version="1.0" encoding="utf-8"?> <resources> <item name="desciption" type="id" /> <item name="cost" type="id" /> <item name="name" type="id" /> <item name="List" type="id"/> </resources>
创建main.xml文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<!-- Main ListView
Always give id value as list(@android:id/list)
-->
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
creare list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<!-- Name Label -->
<TextView
android:id="@+id/name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#dc6800"
android:textSize="16sp"
android:textStyle="bold"
android:paddingTop="6dip"
android:paddingBottom="2dip" />
<!-- Description label -->
<TextView
android:id="@+id/desciption"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#acacac"
android:paddingBottom="2dip">
</TextView>
<!-- Linear layout for cost and price Cost: Rs.100 -->
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<!-- Cost Label -->
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#5d5d5d"
android:gravity="left"
android:textStyle="bold"
android:text="Cost: " >
</TextView>
<!-- Price Label -->
<TextView
android:id="@+id/cost"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#acacac"
android:textStyle="bold"
android:gravity="left">
</TextView>
</LinearLayout>
</LinearLayout>
</LinearLayout>
创建MainActivity.java
import java.util.ArrayList;
import java.util.HashMap;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class MainActivity extends ListActivity {
// All static variables
static final String URL = "http://api.androidhive.info/pizza/?format=xml";
// XML node keys
static final String KEY_ITEM = "item"; // parent node
static final String KEY_ID = "id";
static final String KEY_NAME = "name";
static final String KEY_COST = "cost";
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_ID, parser.getValue(e, KEY_ID));
map.put(KEY_NAME, parser.getValue(e, KEY_NAME));
map.put(KEY_COST, "Rs." + parser.getValue(e, KEY_COST));
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_NAME, KEY_DESC, KEY_COST }, new int[] {
R.id.name, R.id.desciption, R.id.cost });
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
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 description = ((TextView) view.findViewById(R.id.desciption)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
in.putExtra(KEY_NAME, name);
in.putExtra(KEY_COST, cost);
in.putExtra(KEY_DESC, description);
startActivity(in);
}
});
}
}
创建XMLParser.java
import java.io.IOException;
import java.io.StringReader;
import java.io.UnsupportedEncodingException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
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 {
// 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));
}
}
从这里复制的所有代码,您只需要复制粘贴上面的代码,然后让我知道它是否有效
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