ANDROID_MARS学习笔记_S01原始版_020_Mp3player001_歌曲列表

一、项目设计

二、歌曲列表简介

1.利用java.net.HttpURLConnection以流的形式下载xml文件为String

2.自定义ContentHandler--》Mp3ListContentHandler

3.利用自定义的ContentHandler和javax.xml.parsers.SAXParserFactory生成org.xml.sax.XMLReader，用来处理下载的xml字符串，处理结果以List<Mp3Info>返回

4.以返回的List<Mp3Info>和布局文件创建android.widget.SimpleAdapter

5.最后在activity中调用setListAdapter(adapter)，完成更新列表操作

二、代码
1.xml
(1)main.xml

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:orientation="vertical" android:layout_width="fill_parent"
 4     android:layout_height="fill_parent">
 5     <LinearLayout android:id="@+id/listLinearLayout"
 6         android:layout_width="fill_parent" android:layout_height="wrap_content"
 7         android:orientation="vertical">
 8         <ListView android:id="@id/android:list" android:layout_width="fill_parent"
 9             android:layout_height="wrap_content" android:drawSelectorOnTop="false"
10             android:scrollbars="vertical" />
11     </LinearLayout>
12 </LinearLayout>

 

(2)AndroidManifest.xml

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
 3     package="tony.mp3player"
 4     android:versionCode="1"
 5     android:versionName="1.0" >
 6 
 7     <uses-sdk
 8         android:minSdkVersion="8"
 9         android:targetSdkVersion="21" />
10 
11     <application
12         android:allowBackup="true"
13         android:icon="@drawable/ic_launcher"
14         android:label="@string/app_name"
15         android:theme="@style/AppTheme" >
16         <activity
17             android:name=".Mp3ListActivity"
18             android:label="@string/app_name" >
19             <intent-filter>
20                 <action android:name="android.intent.action.MAIN" />
21 
22                 <category android:name="android.intent.category.LAUNCHER" />
23             </intent-filter>
24         </activity>
25     </application>
26     <uses-permission android:name="android.permission.INTERNET"/>
27 </manifest>

 

3.mp3info_item.xml

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="fill_parent"
 4     android:layout_height="fill_parent"
 5     android:orientation="horizontal"
 6     android:paddingLeft="10dip"
 7     android:paddingRight="10dip"
 8     android:paddingTop="1dip"
 9     android:paddingBottom="1dip"
10     >
11     <TextView android:id="@+id/mp3Name"
12     android:layout_height="30dip"
13     android:layout_width="180dip"
14     android:textSize="10pt"/>
15     <TextView android:id="@+id/mp3Size"
16     android:layout_height="30dip"
17     android:layout_width="180dip"
18     android:textSize="10pt"/>
19 </LinearLayout>

 

2.java
(1)Mp3ListActivity.java

  1 package tony.mp3player;
  2 
  3 import java.io.IOException;
  4 import java.io.StringReader;
  5 import java.util.ArrayList;
  6 import java.util.HashMap;
  7 import java.util.Iterator;
  8 import java.util.List;
  9 import java.util.Map;
 10 
 11 import javax.xml.parsers.ParserConfigurationException;
 12 import javax.xml.parsers.SAXParserFactory;
 13 
 14 import org.xml.sax.InputSource;
 15 import org.xml.sax.SAXException;
 16 import org.xml.sax.XMLReader;
 17 
 18 import tony.download.HttpDownloader;
 19 import tony.model.Mp3Info;
 20 import tony.xml.Mp3ListContentHandler;
 21 import android.annotation.SuppressLint;
 22 import android.app.ListActivity;
 23 import android.os.Bundle;
 24 import android.os.StrictMode;
 25 import android.view.Menu;
 26 import android.view.MenuItem;
 27 import android.widget.SimpleAdapter;
 28 
 29 @SuppressLint("NewApi")
 30 public class Mp3ListActivity extends ListActivity {
 31     private static final int UPDATE = 1;
 32     private static final int ABOUT = 1;
 33     @Override
 34     protected void onCreate(Bundle savedInstanceState) {
 35         super.onCreate(savedInstanceState);
 36         setContentView(R.layout.main);
 37         if (android.os.Build.VERSION.SDK_INT > 9) {
 38             StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
 39             StrictMode.setThreadPolicy(policy);
 40         }
 41         updateListView();
 42     }
 43     
 44     /**
 45      * 在用点击MENU按钮之后，会调用该方法，我们可以在这个方法当中加入自己的按钮控件
 46      */
 47     @Override
 48     public boolean onCreateOptionsMenu(Menu menu) {
 49         menu.add(0, UPDATE, UPDATE, R.string.mp3list_update);
 50         menu.add(0, ABOUT, ABOUT, R.string.mp3list_about);
 51         return super.onCreateOptionsMenu(menu);
 52     }
 53     
 54     /**
 55      * 当菜单选项被选中时调用
 56      */
 57     @Override
 58     public boolean onOptionsItemSelected(MenuItem item) {
 59         System.out.println("onOptionsItemSelected--->ItemId="+item.getItemId());
 60         switch (item.getItemId()) {
 61         case UPDATE:
 62             updateListView();
 63             break;
 64         case 2:
 65             break;
 66         default:
 67             break;
 68         }
 69         return super.onOptionsItemSelected(item);
 70     }
 71     
 72     private void updateListView() {
 73         String xml = downloadXML("http://192.168.1.104:8080/mp3/resources.xml");
 74         List<Mp3Info> infos = parse(xml);
 75         SimpleAdapter adapter = buidSimpleAdapter(infos);
 76         setListAdapter(adapter);
 77     }
 78 
 79     private SimpleAdapter buidSimpleAdapter(List<Mp3Info> infos) {
 80         // 生成一个List对象，并按照SimpleAdapter的标准，将mp3Infos当中的数据添加到List当中去
 81         List<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();
 82         HashMap<String,String> map = null;
 83         Mp3Info info = null;
 84         for(Iterator it = infos.iterator() ; it.hasNext() ;) {
 85             info = (Mp3Info) it.next();
 86             map = new HashMap<String,String>();
 87             map.put("mp3Name", info.getMp3Name());
 88             map.put("mp3Size", info.getMp3Size());
 89             list.add(map);
 90         }
 91         SimpleAdapter adapter = new SimpleAdapter(this, list, R.layout.mp3info_item, 
 92                 new String[]{"mp3Name", "mp3Size"}, new int[]{R.id.mp3Name, R.id.mp3Size});
 93         return adapter;
 94     }
 95 
 96     private String downloadXML(String urlStr) {
 97         HttpDownloader httpDownloader = new HttpDownloader();
 98         String result = httpDownloader.download(urlStr);
 99         return result;
100     }
101     
102     private List<Mp3Info> parse(String xml) {
103         SAXParserFactory spf =  SAXParserFactory.newInstance();
104         List<Mp3Info> infos = new ArrayList<Mp3Info>();
105         try {
106             XMLReader reader = spf.newSAXParser().getXMLReader();
107             Mp3ListContentHandler handler = new Mp3ListContentHandler(infos);
108             reader.setContentHandler(handler);
109             reader.parse(new InputSource(new StringReader(xml)));
110             for(Iterator it = infos.iterator();it.hasNext();) {
111                 Mp3Info info = (Mp3Info) it.next();
112                 System.out.println(info);
113             }
114         } catch (SAXException e) {
115             e.printStackTrace();
116         } catch (ParserConfigurationException e) {
117             e.printStackTrace();
118         } catch (IOException e) {
119             e.printStackTrace();
120         }
121         return infos;
122     }
123 }

 

(2)Mp3ListContentHandler.java

 1 package tony.xml;
 2 
 3 import java.util.List;
 4 
 5 import org.xml.sax.Attributes;
 6 import org.xml.sax.SAXException;
 7 import org.xml.sax.helpers.DefaultHandler;
 8 
 9 import tony.model.Mp3Info;
10 
11 public class Mp3ListContentHandler extends DefaultHandler {
12 
13     private List<Mp3Info> infos = null;
14     private Mp3Info mp3Info = null;
15     private String tagName = null;
16 
17     public Mp3ListContentHandler(List<Mp3Info> infos) {
18         super();
19         this.infos = infos;
20     }
21 
22     @Override
23     public void startDocument() throws SAXException {
24         super.startDocument();
25     }
26 
27     @Override
28     public void endDocument() throws SAXException {
29         super.endDocument();
30     }
31 
32     @Override
33     public void startElement(String uri, String localName, String qName,
34             Attributes attributes) throws SAXException {
35         this.tagName = localName;
36         if(tagName.equals("resource")) {
37             mp3Info = new Mp3Info();
38         }
39     }
40 
41     @Override
42     public void endElement(String uri, String localName, String qName)
43             throws SAXException {
44         if(qName.equals("resource")) {
45             infos.add(mp3Info);
46         }
47         tagName = "";
48     }
49 
50     @Override
51     public void characters(char[] ch, int start, int length)
52             throws SAXException {
53         String temp = new String(ch, start, length);
54         if(tagName.equals("id")) 
55             mp3Info.setId(temp);
56         else if(tagName.equals("mp3.name"))
57             mp3Info.setMp3Name(temp);
58         else if(tagName.equals("mp3.size"))
59             mp3Info.setMp3Size(temp);
60         else if(tagName.equals("lrc.name"))
61             mp3Info.setLrcName(temp);
62         else if(tagName.equals("lrc.size"))
63             mp3Info.setLrcSize(temp);
64     }
65 }

 

(3)HttpDownloader.java

 1 package tony.download;
 2 
 3 import java.io.BufferedReader;
 4 import java.io.InputStreamReader;
 5 import java.net.HttpURLConnection;
 6 import java.net.URL;
 7 
 8 public class HttpDownloader {
 9 
10     /**
11      * 根据URL下载文件，前提是这个文件当中的内容是文本，函数的返回值就是文件当中的内容
12      * 1.创建一个URL对象
13      * 2.通过URL对象，创建一个HttpURLConnection对象
14      * 3.得到InputStram
15      * 4.从InputStream当中读取数据
16      * @param urlStr
17      * @return
18      */
19     public String download(String urlStr) {
20         StringBuffer sb = new StringBuffer();
21         String line = null;
22         BufferedReader buffer = null;
23         try {
24             // 创建一个URL对象
25             URL url = new URL(urlStr);
26             // 创建一个Http连接
27             HttpURLConnection urlConn = (HttpURLConnection) url
28                     .openConnection();
29             // 使用IO流读取数据
30             buffer = new BufferedReader(new InputStreamReader(urlConn
31                     .getInputStream()));
32             while ((line = buffer.readLine()) != null) {
33                 sb.append(line);
34             }
35         } catch (Exception e) {
36             e.printStackTrace();
37         } finally {
38             try {
39                 buffer.close();
40             } catch (Exception e) {
41                 e.printStackTrace();
42             }
43         }
44         return sb.toString();
45     }
46 }

 

(4)

 1 package tony.model;
 2 
 3 public class Mp3Info {
 4 
 5     private String id,mp3Name,mp3Size,lrcName,lrcSize;
 6 
 7     public Mp3Info() {
 8         super();
 9     }
10 
11     public Mp3Info(String id, String mp3Name, String mp3Size, String lrcName,
12             String lrcSize) {
13         super();
14         this.id = id;
15         this.mp3Name = mp3Name;
16         this.mp3Size = mp3Size;
17         this.lrcName = lrcName;
18         this.lrcSize = lrcSize;
19     }
20 
21     @Override
22     public String toString() {
23         return "Mp3Info [id=" + id + ", mp3Name=" + mp3Name + ", mp3Size="
24                 + mp3Size + ", lrcName=" + lrcName + ", lrcSize=" + lrcSize
25                 + "]";
26     }
27 
28     public String getId() {
29         return id;
30     }
31 
32     public void setId(String id) {
33         this.id = id;
34     }
35 
36     public String getMp3Name() {
37         return mp3Name;
38     }
39 
40     public void setMp3Name(String mp3Name) {
41         this.mp3Name = mp3Name;
42     }
43 
44     public String getMp3Size() {
45         return mp3Size;
46     }
47 
48     public void setMp3Size(String mp3Size) {
49         this.mp3Size = mp3Size;
50     }
51 
52     public String getLrcName() {
53         return lrcName;
54     }
55 
56     public void setLrcName(String lrcName) {
57         this.lrcName = lrcName;
58     }
59 
60     public String getLrcSize() {
61         return lrcSize;
62     }
63 
64     public void setLrcSize(String lrcSize) {
65         this.lrcSize = lrcSize;
66     }
67     
68     
69 }

 

四、运行结果