Android 下载XML文件时出现异常

我正在开发一个Android应用程序，我正在尝试从这个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

我想在点击按钮时下载文件。因此，我在单击按钮时使用以下代码

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();
    }

正如我使用的

try and catch

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？

将权限放入清单文件

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

---

检查您的清单文件、是否授予权限，并使用AsyncTask或线程概念进行url连接（后台工作）

---

这个错误正在发生

如果你忘了写这个

如果您的互联网速度很慢或无法正常工作

最后，如果您的服务器由于任何原因没有响应您的请求 试试这个

URL url = new URL(Your URL);

                //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/");

                //create a new file, specifying the path, and the filename

                //which we want to save the file as.

                File file = new File(SDCardRoot,"hello.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();

---

我想下载XML文件及其类似的web服务…因此，如果有任何错误，请让我知道..“您请求的页面不可用”。@H.Moody:我已经提供了我要下载的链接，它也在我的浏览器中打开。那么，请确切地告诉我问题出在哪里？你在清单中添加了互联网权限了吗file@Droid：是的，现在我已经添加了权限，但是现在得到了这个异常

java.io.FileNotFoundException:/sdcard/XML\u folder/webservice.XML（没有这样的文件或目录）

帮助？你能解释一下你的概念吗。事实上，我是Android开发的新手。所以，这对我来说是件好事。@Shiv你在设备或模拟器中运行你的应用程序在哪里？你能发布你的清单文件吗？嘿，正如你所说的，我已经添加了使用互联网的权限

，但现在我得到了这个

java.io.FileNotFoundException:/sdcard/XML\u文件夹/webservice.XML（没有这样的文件或目录）

help？？我在中运行我的应用程序device@Shiv文件根=新文件（Environment.getExternalStorageDirectory（），“/sdcard/XML_folder”）；如果（！root.exists（））{root.mkdirs（）；}文件gpxfile=新文件（根，“webservice.xml”）；我怎么能忘记这一点呢..顺便说一句谢谢..但是现在我得到了

java.io.FileNotFoundException:/sdcard/XML\u folder/webservice.XML（没有这样的文件或目录）

XML没有下载到这个/sdcard/XML\u folder/webservice.XML位置检查中。！！我必须创建这个位置吗？我的问题解决了。现在，您可以帮助我

如何在我的应用程序中使用此XML文件数据吗`
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            new Thread(new Runnable() 
                {
                  public void run() 
                    {
                try
                 {
                     //http connection code. 
                 }      
                          catch(Exception e) 
                         {
                        Toast.makeText(getApplicationContext(), e.getMessage(), Toast.LENGTH_SHORT).show(); 
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                }).start();


        }}); 

URL url = new URL(Your URL);

                //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/");

                //create a new file, specifying the path, and the filename

                //which we want to save the file as.

                File file = new File(SDCardRoot,"hello.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();