我正在开发一个 Android 应用程序,我正在尝试从此 URL 下载 XML 文件 http://data.gov.in/sites/default/files/Date-Wise-Prices-all-Commodity .xml
并尝试将此文件保存到我的 SD 卡中。
我想在单击按钮时下载文件。所以,我在 Button Click 上使用了以下代码..
try
{
URL url = new URL("http://data.gov.in/sites/default/files/Date-Wise-Prices-all-Commodity.xml");
//create the new connection
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
//set up some things on the connection
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
//and connect!
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 = new File("/sdcard/"+"XML_folder/");
//create a new file, specifying the path, and the filename
//which we want to save the file as.
File file = new File(SDCardRoot,"webservice.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();
//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;
int progress=(int)(downloadedSize*100/totalSize);
//this is where you would do something to report the prgress, like this maybe
//updateProgress(downloadedSize, totalSize);
}
//close the output stream when done
fileOutput.close();
}
catch(Exception e)
{
Toast.makeText(getApplicationContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
}
当我使用 try and catch
时,它会捕获异常并向我显示此消息 data.gov.in
(java.net.UnknownHostException: data. gov.in)
那么,现在该怎么办?
最佳答案
检查您的 list 文件,是否授予权限,并使用 AsyncTask 或线程概念进行 url 连接(后台工作)。
ibut.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
new Thread(new Runnable()
{
public void run()
{
try
{
//http connection code.
}
catch(Exception e)
{
Toast.makeText(getApplicationContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
}
}).start();
}});
关于android - 下载 XML 文件时出现异常,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19443273/