保存來自Url的XML並閱讀它

Question

我在製作android應用程序，我需要從URL下載xml文件並將其打開， 我該如何做到這一點？

public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 

    File dir1 = getDir("xmls",Context.MODE_PRIVATE);//Creating an internal dir; 
    System.out.println("dir1: " + dir1); 

    //Saving The File 
    try { 
     URL url = new URL("http://www. the url of my xml .xml"); 
     // The server thinks this request is from an Opera browser! 
     String userAgent = "Opera/9.63 (Windows NT 5.1; U; en) Presto/2.1.1"; 
     System.out.println("Downloading ..."); 
     downloadFromUrl(url, dir1+"news.xml", userAgent); 
     System.out.println("OK"); 
} catch (Exception e) { 
     System.err.println(e); 
     System.out.println("Entri pure nel catch"); 
    } 
    //This is the path of the xml file that i have saved 
    URL = dir1+"/news.xml" ; 
    ArrayList<HashMap<String, String>> songsList = 
             new ArrayList<HashMap<String, String>>(); 
    XMLParser parser = new XMLParser(); 
    String xml = parser.getXmlFromUrl(URL); // getting XML from UR 
    Document doc = parser.getDomElement(xml); // getting DOM element 
    //And then i do all the parsing 
    NodeList nl = doc.getElementsByTagName(KEY_CATEGORIA); 

而且XMlParser類是這樣的：

public class XMLParser_Categorie { 

// constructor 
public XMLParser_Categorie() { 

} 

/** 
* 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; 
} 

我需要改變這個指令：

DefaultHttpClient httpClient = new DefaultHttpClient(); 
HttpPost httpPost = new HttpPost(url); 
HttpResponse httpResponse = httpClient.execute(httpPost); 
HttpEntity httpEntity = httpResponse.getEntity(); 
xml = EntityUtils.toString(httpEntity); 

它從本地目錄和非HTTP請求的請求。

Answer 1

這裏是你的代碼片段，

try { 

     URL url = new URL("your url goes here"); 

     //create the new connection 
     HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection(); 

     urlConnection.connect(); 

     //set the path where we want to save the file 
     //in this case, going to save it on the root directory of the 
     //sd card. 
     File SDCardRoot = Environment.getExternalStorageDirectory(); 
     //create a new file, specifying the path, and the filename 
     //which we want to save the file as. 
     File file = new File(SDCardRoot,"Demo.xml"); 

     //this will be used to write the downloaded data into the file we created 
     FileOutputStream fileOutput = new FileOutputStream(file); 

     //this will be used in reading the data from the internet 
     InputStream inputStream = urlConnection.getInputStream(); 

     //this is the total size of the file 
     int totalSize = urlConnection.getContentLength(); 
     progressDialog.setMax(totalSize); 

     //variable to store total downloaded bytes 
     int downloadedSize = 0; 

     //create a buffer... 
     byte[] buffer = new byte[1024]; 
     int bufferLength = 0; //used to store a temporary size of the buffer 

     //now, read through the input buffer and write the contents to the file 
     while ((bufferLength = inputStream.read(buffer)) > 0) { 
       //add the data in the buffer to the file in the file output stream (the file on the sd card 
       fileOutput.write(buffer, 0, bufferLength); 
       //add up the size so we know how much is downloaded 
       downloadedSize += bufferLength; 

     } 
     //close the output stream when done 
     fileOutput.close(); 
     //catch some possible errors... 
} catch (MalformedURLException e) { 
     e.printStackTrace(); 
} catch (IOException e) { 
     e.printStackTrace(); 
} 

否則這些鏈接可以幫助你，

1）Read remote XML in android

2）Download remote XML and store it in android