学步园

首先在电脑上配置tomcat，webapps目录下新建mp3文件夹，

截图

首先我们通过SAX解析resources.xml 获取歌曲信息。

启动 Tomcat访问一下服务器地址http://210.**.**.**:8080/mp3/resources.xml

210.**.**.**是我的IP，把这里改成自己的IP

本来下载是一个耗时的东西，需要另外开启一个线程或则service去下载，由于这里就在本人的电脑上测试

就在主线程中下载了

Info.java

package rw.down;</p> <p>public class Info {<br /> int id;<br /> String nameString;<br /> /**<br /> * @return the id<br /> */<br /> public int getId() {<br /> return id;<br /> }<br /> /**<br /> * @param id the id to set<br /> */<br /> public void setId(int id) {<br /> this.id = id;<br /> }<br /> /**<br /> * @return the nameString<br /> */<br /> public String getNameString() {<br /> return nameString;<br /> }<br /> /**<br /> * @param nameString the nameString to set<br /> */<br /> public void setNameString(String nameString) {<br /> this.nameString = nameString;<br /> }<br /> /* (non-Javadoc)<br /> * @see java.lang.Object#toString()<br /> */<br /> @Override<br /> public String toString() {<br /> return "info [id=" + id + ", nameString=" + nameString + "]";<br /> }<br /> }<br />

infoHandle.java

package rw.down;</p> <p>import java.util.List;</p> <p>import org.xml.sax.Attributes;<br /> import org.xml.sax.SAXException;<br /> import org.xml.sax.helpers.DefaultHandler;</p> <p>import android.util.Log;</p> <p>public class infoHandle extends DefaultHandler {</p> <p> private Info Mp3_info;<br /> private List<Info> List_Mp3_Infos;<br /> private String preString;</p> <p> public infoHandle() {<br /> super();<br /> }</p> <p> public infoHandle(List<Info> list_Mp3_Infos) {<br /> super();<br /> List_Mp3_Infos = list_Mp3_Infos;<br /> }</p> <p> @Override<br /> public void startDocument() throws SAXException {<br /> // TODO Auto-generated method stub<br /> super.startDocument();<br /> }</p> <p> @Override<br /> public void startElement(String uri, String localName, String qName,<br /> Attributes attributes) throws SAXException {<br /> // TODO Auto-generated method stub<br /> preString=localName;<br /> if (preString.equals("resource")) {<br /> Mp3_info=new Info();<br /> }<br /> super.startElement(uri, localName, qName, attributes);<br /> }</p> <p> public void endElement(String uri, String localName, String qName)<br /> throws SAXException {<br /> // TODO Auto-generated method stub<br /> preString=" ";<br /> Log.i("endElement_localName-------->", localName);<br /> if (localName.equals("resource")) {<br /> List_Mp3_Infos.add(Mp3_info);<br /> }<br /> super.endElement(uri, localName, qName);<br /> }</p> <p> @Override<br /> public void characters(char[] ch, int start, int length)<br /> throws SAXException {<br /> // TODO Auto-generated method stub<br /> String dateString;<br /> dateString=new String(ch, start, length);<br /> if (preString.equals("id")) {<br /> Mp3_info.setId(Integer.parseInt(dateString));<br /> Log.i("id--------->", dateString);<br /> }else if (preString.equals("mp3.name")) {<br /> Mp3_info.setNameString(dateString);<br /> Log.i("mp3.name--------->", dateString);<br /> }</p> <p> super.characters(ch, start, length);<br /> }</p> <p> @Override<br /> public void endDocument() throws SAXException {<br /> // TODO Auto-generated method stub<br /> super.endDocument();<br /> }</p> <p>}<br />

DonwnFileActivity.java

package rw.down;</p> <p>import java.io.File;<br /> import java.io.FileOutputStream;<br /> import java.io.IOException;<br /> import java.io.InputStream;<br /> import java.io.OutputStream;</p> <p>import java.net.HttpURLConnection;<br /> import java.net.MalformedURLException;<br /> import java.net.URL;<br /> import java.util.ArrayList;<br /> import java.util.Iterator;<br /> import java.util.List;</p> <p>import javax.xml.parsers.ParserConfigurationException;<br /> import javax.xml.parsers.SAXParser;<br /> import javax.xml.parsers.SAXParserFactory;</p> <p>import org.apache.http.HttpConnection;<br /> import org.apache.http.message.BufferedHeader;<br /> import org.xml.sax.InputSource;<br /> import org.xml.sax.SAXException;<br /> import org.xml.sax.XMLReader;<br /> import org.xmlpull.v1.XmlPullParser;<br /> import org.xmlpull.v1.XmlPullParserException;<br /> import org.xmlpull.v1.XmlPullParserFactory;</p> <p>import android.app.Activity;<br /> import android.app.ProgressDialog;<br /> import android.content.Intent;<br /> import android.content.res.AssetManager.AssetInputStream;<br /> import android.os.Bundle;<br /> import android.os.Environment;<br /> import android.util.Log;<br /> import android.view.MenuItem;<br /> import android.view.View;<br /> import android.view.View.OnClickListener;<br /> import android.widget.AdapterView;<br /> import android.widget.AdapterView.OnItemClickListener;<br /> import android.widget.ArrayAdapter;<br /> import android.widget.Button;<br /> import android.widget.ListAdapter;<br /> import android.widget.ListView;<br /> import android.widget.SimpleAdapter;<br /> import android.widget.TextView;<br /> import android.widget.Toast;</p> <p>public class DownFileActivity extends Activity {<br /> /** Called when the activity is first created. */<br /> private Button button;<br /> private ListView listView;<br /> private List<String> list=new ArrayList<String>();<br /> private ArrayAdapter<String> adapter1;<br /> private List<String> musicnameList;<br /> private Intent service;<br /> @Override<br /> public void onCreate(Bundle savedInstanceState) {<br /> super.onCreate(savedInstanceState);<br /> setContentView(R.layout.main);<br /> service=new Intent(this,DownService.class);<br /> button=(Button) findViewById(R.id.button1);<br /> listView=(ListView) findViewById(R.id.listView1);<br /> button.setOnClickListener(new Mybutton());<br /> }<br /> class Mybutton implements OnClickListener{</p> <p> @Override<br /> public void onClick(View v) {</p> <p> // TODO Auto-generated method stub<br /> button.setText("刷新列表");<br /> musicnameList=new ArrayList<String>();<br /> List<Info> lInfos=parseXML();<br /> list.clear();<br /> adapter1 =new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, list);<br /> listView.setAdapter(adapter1);<br /> for (Iterator iterator = lInfos.iterator(); iterator.hasNext();) {<br /> Info info = (Info) iterator.next();<br /> musicnameList.add(info.getNameString());<br /> list.add(info.getId()+" "+info.getNameString());<br /> }<br /> adapter1 =new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, list);<br /> listView.setAdapter(adapter1);<br /> listView.setOnItemClickListener(new ItemLitener());<br /> }</p> <p> }<br /> private List<Info> parseXML()<br /> {<br /> List<Info> infos=null;</p> <p> SAXParserFactory factory=SAXParserFactory.newInstance();<br /> try {</p> <p> URL url=new URL("http://210.30.12.34:8080/mp3/resources.xml");</p> <p> HttpURLConnection connection=(HttpURLConnection) url.openConnection();<br /> if (connection.getReadTimeout()==4) {</p> <p> Toast.makeText(getApplicationContext(), "请求超时", Toast.LENGTH_LONG).show();<br /> return null;<br /> }<br /> InputStream inputStream2=connection.getInputStream();<br /> SAXParser parser=factory.newSAXParser();<br /> XMLReader reader=parser.getXMLReader();<br /> infos=new ArrayList<Info>();<br /> reader.setContentHandler(new infoHandle(infos));<br /> reader.parse(new InputSource(inputStream2));</p> <p> } catch (ParserConfigurationException e) {<br /> // TODO Auto-generated catch block<br /> e.printStackTrace();<br /> } catch (SAXException e) {<br /> // TODO Auto-generated catch block<br /> e.printStackTrace();<br /> } catch (MalformedURLException e) {<br /> // TODO Auto-generated catch block<br /> e.printStackTrace();<br /> } catch (IOException e) {<br /> // TODO Auto-generated catch block<br /> e.printStackTrace();<br /> }<br /> return infos;<br /> }<br /> private class ItemLitener implements OnItemClickListener{</p> <p> @Override<br /> public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {<br /> // TODO Auto-generated method stub</p> <p> Toast.makeText( getApplicationContext(), musicnameList.get(arg2).toString(), Toast.LENGTH_LONG).show();<br /> String downUrlString="http://210.30.12.34:8080/mp3/"+musicnameList.get(arg2).toString();<br /> String sdcardSave="DownFile";<br /> String filename=musicnameList.get(arg2).toString();<br /> OutputStream outputStream=null;<br /> HttpURLConnection connection;<br /> /*<br /> * 1.在AndroidMainfest.xml中进行权限配置<br /> * <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /><br /> * 取得写入SDCard的权限<br /> * 2.取得SDCard的路径： Environment.getExternalStorageDirectory()<br /> * 3.检查要保存的文件上是否已经存在<br /> * 4.不存在，新建文件夹，新建文件<br /> * 5.将input流中的信息写入SDCard<br /> * 6.关闭流<br /> */<br /> String SDcardPath=Environment.getExternalStorageDirectory()+"";<br /> String pathString=SDcardPath+"/"+sdcardSave+"/"+filename;<br /> File file=new File(pathString);</p> <p> startService(service);<br /> try {<br /> connection = (HttpURLConnection) new URL(downUrlString).openConnection();<br /> InputStream inputStream=connection.getInputStream();<br /> if (!file.exists()) {<br /> new File(SDcardPath+"/"+sdcardSave).mkdir();<br /> }<br /> File[] filelist=new File(SDcardPath+"/"+sdcardSave).listFiles();<br /> for (int i = 0; i < filelist.length; i++) {<br /> if (filelist[i].getName().equals(filename)) {<br /> Toast.makeText(getApplicationContext(), filename+"已经存在", Toast.LENGTH_LONG).show();<br /> return ;<br /> }<br /> }<br /> file.createNewFile();<br /> System.err.println("开始下载");</p> <p> outputStream=new FileOutputStream(file);<br /> byte[] buffer=new byte[4*1024];<br /> while ((inputStream.read(buffer))!=-1) {<br /> outputStream.write(buffer);<br /> }<br /> outputStream.flush();<br /> } catch (IOException e) {<br /> // TODO Auto-generated catch block<br /> e.printStackTrace();<br /> }finally{<br /> try {<br /> outputStream.close();<br /> Toast.makeText(getApplicationContext(), "下载成功", Toast.LENGTH_LONG).show();<br /> System.err.println("下载完成");<br /> //progressDialog.dismiss();<br /> } catch (Exception e2) {<br /> // TODO: handle exception<br /> Toast.makeText(getApplicationContext(), "下载失败", Toast.LENGTH_LONG).show();<br /> //progressDialog.cancel();<br /> }</p> <p> }<br /> }</p> <p> }<br /> }

DownService.java

package rw.down;<br /> import android.app.Service;<br /> import android.content.Intent;<br /> import android.os.IBinder;<br /> import android.widget.Toast;</p> <p>public class DownService extends Service {</p> <p> @Override<br /> public IBinder onBind(Intent arg0) {<br /> // TODO Auto-generated method stub<br /> return null;<br /> }</p> <p> public void onCreate() {<br /> // TODO Auto-generated method stub<br /> super.onCreate();<br /> }</p> <p> public void onDestroy() {<br /> // TODO Auto-generated method stub<br /> super.onDestroy();<br /> }</p> <p> public void onStart(Intent intent, int startId) {<br /> // TODO Auto-generated method stub<br /> Toast.makeText(getApplicationContext(), "服务开始", Toast.LENGTH_LONG).show();<br /> super.onStart(intent, startId);<br /> }</p> <p>}<br />

在AndroidManifest.xml中添加两个权限

<uses-permission android:name="android.permission.INTERNET"></uses-permission><br /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

和一个服务

<service android:name="DownService"></service>

效果，因为我已经运行过了，因为我已经运行过了，所以DownFile这个文件已经存在，第一次运行是回创建这个文件夹

通过ls命令 我们看见  现在文件夹里面什么也没有

点击我们要下载的歌曲，我现在点击Beyond.mo3

如果下载成功

如果没有找到这个歌曲，会提示下载失败

现在我们再来看看DownFile这个文件夹下面