Android 声明URL的正确方法？

在我的应用程序中，我试图从我的网站下载一个文件，但我遇到了一些问题。首先，我似乎无法找到正确的方法来声明URL。其次，当我运行应用程序时，当我告诉连接获取InputStream时，它会崩溃。我不知道我做错了什么。我在网上搜索了一下午的大部分时间，尝试了很多方法来解决URL的问题，但都没有成功

我很想知道我做错了什么，所以任何帮助都将不胜感激

package shc_BalloonSat.namespace;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;

import org.apache.http.util.ByteArrayBuffer;

import android.util.Log;

public class dl_viewKML
{
    String file_path = "";
    String file_url;
    String file_name;

    void downloadFile()
    {
        try
        {
            String file_name = "data.kml";

            //URL url = new URL("http://space.uah.edu");
            String encodedURL = "http:////"+URLEncoder.encode("www.wktechnologies.com/shc_android_app/", "UTF-8");
            URL url = new URL(encodedURL);
            File file = new File(url + "/" + file_name);

            long startTime = System.currentTimeMillis();
            Log.d("SHC BalloonSat", "Download beginning: ");
            Log.d("SHC BalloonSat", "Download url: " + url);
            Log.d("SHC BalloonSat", "Downloaded file name: " + file_name);

            // Open a connection to the specified URL
            URLConnection conn = url.openConnection();

            // Define InputStreams to read from the URLConnection.
            InputStream is = conn.getInputStream();//crashes here
            BufferedInputStream bis = new BufferedInputStream(is);

            // Read bytes to the Buffer until there is nothing more to read(-1).
            ByteArrayBuffer baf = new ByteArrayBuffer(50);
            int current = 0;
            while ((current = bis.read()) != -1)
            {
                baf.append((byte) current);
            }

            // Convert the Bytes read to a String.
            FileOutputStream fos = new FileOutputStream(file);
            fos.write(baf.toByteArray());
            fos.close();
            Log.d("SHC BalloonSat", "Download ready in: " + ((System.currentTimeMillis() - startTime) / 1000) + " secs.");
            }

            catch (IOException e)
            {
                Log.e("log_tag", "Error: " + e.toString());
            }   
    }
}

---

不需要使用url调用URLEncoder。URLEncoder.encode用于对参数进行编码：

因此，请编辑代码以：

void downloadFile()
{
    try
    {
        String file_name = "data.kml";

        //URL url = new URL("http://space.uah.edu");
        String encodedURL =         "http://"+"www.wktechnologies.com/shc_android_app/data.kml";
        URL url = new URL(encodedURL);

        // Open a connection to the specified URL
        URLConnection conn = url.openConnection();

        // Define InputStreams to read from the URLConnection.
        InputStream is = conn.getInputStream();//crashes here
        BufferedInputStream bis = new BufferedInputStream(is);

        // Read bytes to the Buffer until there is nothing more to read(-1).
        ByteArrayBuffer baf = new ByteArrayBuffer(50);
        int current = 0;
        while ((current = bis.read()) != -1)
        {
            baf.append((byte) current);
        }

        // Convert the Bytes read to a String.
        FileOutputStream fos = new FileOutputStream(file);
        fos.write(baf.toByteArray());
        fos.close();
        Log.d("SHC BalloonSat", "Download ready in: " + ((System.currentTimeMillis() - startTime) / 1000) + " secs.");
    }

    catch (IOException e)
    {
        Log.e("log_tag", "Error: " + e.toString());
    }

}

---

不需要使用url调用URLEncoder。URLEncoder.encode用于对参数进行编码：

因此，请编辑代码以：

void downloadFile()
{
    try
    {
        String file_name = "data.kml";

        //URL url = new URL("http://space.uah.edu");
        String encodedURL =         "http://"+"www.wktechnologies.com/shc_android_app/data.kml";
        URL url = new URL(encodedURL);

        // Open a connection to the specified URL
        URLConnection conn = url.openConnection();

        // Define InputStreams to read from the URLConnection.
        InputStream is = conn.getInputStream();//crashes here
        BufferedInputStream bis = new BufferedInputStream(is);

        // Read bytes to the Buffer until there is nothing more to read(-1).
        ByteArrayBuffer baf = new ByteArrayBuffer(50);
        int current = 0;
        while ((current = bis.read()) != -1)
        {
            baf.append((byte) current);
        }

        // Convert the Bytes read to a String.
        FileOutputStream fos = new FileOutputStream(file);
        fos.write(baf.toByteArray());
        fos.close();
        Log.d("SHC BalloonSat", "Download ready in: " + ((System.currentTimeMillis() - startTime) / 1000) + " secs.");
    }

    catch (IOException e)
    {
        Log.e("log_tag", "Error: " + e.toString());
    }

}

使用字符串encodedURL=”http://www.wktechnologies.com/shc_android_app/"; 对于您应用的编码不正确，请参阅RFC3986（）的第3节。它告诉您如何对URI的各个部分进行编码。不幸的是，URI的每个部分（主机、路径、查询等）的编码规则略有不同

使用字符串encodedURL=”http://www.wktechnologies.com/shc_android_app/";

---

对于您应用的编码不正确，请参阅RFC3986（）的第3节。它告诉您如何对URI的各个部分进行编码。不幸的是，URI的每个部分（主机、路径、查询等）的编码规则略有不同

确保在您的清单中，您已声明允许访问internet

您可以使用以下命令

public class dl_viewKML
{

private static final String encodedURL ="http://www.wktechnologies.com/shc_android_app/";
String file_path = "";
String file_url;
String file_name;

void downloadFile()
{
try
{
    String file_name = "data.kml";

    //URL url = new URL("http://space.uah.edu");

    URL url = new URL(encodedURL);
    File file = new File(url + "/" + file_name);

    long startTime = System.currentTimeMillis();
    Log.d("SHC BalloonSat", "Download beginning: ");
    Log.d("SHC BalloonSat", "Download url: " + url);
    Log.d("SHC BalloonSat", "Downloaded file name: " + file_name);

    // Open a connection to the specified URL
    URLConnection conn = url.openConnection();

    // Define InputStreams to read from the URLConnection.
    InputStream is = conn.getInputStream();//crashes here
    BufferedInputStream bis = new BufferedInputStream(is);

    // Read bytes to the Buffer until there is nothing more to read(-1).
    ByteArrayBuffer baf = new ByteArrayBuffer(50);
    int current = 0;
    while ((current = bis.read()) != -1)
    {
        baf.append((byte) current);
    }

    // Convert the Bytes read to a String.
    FileOutputStream fos = new FileOutputStream(file);
    fos.write(baf.toByteArray());
    fos.close();
    Log.d("SHC BalloonSat", "Download ready in: " + ((System.currentTimeMillis() - startTime) / 1000) + " secs.");
}

catch (IOException e)
{
    Log.e("log_tag", "Error: " + e.toString());
}

}

---

请确保在您的清单中，您已声明允许访问internet

您可以使用以下命令

public class dl_viewKML
{

private static final String encodedURL ="http://www.wktechnologies.com/shc_android_app/";
String file_path = "";
String file_url;
String file_name;

void downloadFile()
{
try
{
    String file_name = "data.kml";

    //URL url = new URL("http://space.uah.edu");

    URL url = new URL(encodedURL);
    File file = new File(url + "/" + file_name);

    long startTime = System.currentTimeMillis();
    Log.d("SHC BalloonSat", "Download beginning: ");
    Log.d("SHC BalloonSat", "Download url: " + url);
    Log.d("SHC BalloonSat", "Downloaded file name: " + file_name);

    // Open a connection to the specified URL
    URLConnection conn = url.openConnection();

    // Define InputStreams to read from the URLConnection.
    InputStream is = conn.getInputStream();//crashes here
    BufferedInputStream bis = new BufferedInputStream(is);

    // Read bytes to the Buffer until there is nothing more to read(-1).
    ByteArrayBuffer baf = new ByteArrayBuffer(50);
    int current = 0;
    while ((current = bis.read()) != -1)
    {
        baf.append((byte) current);
    }

    // Convert the Bytes read to a String.
    FileOutputStream fos = new FileOutputStream(file);
    fos.write(baf.toByteArray());
    fos.close();
    Log.d("SHC BalloonSat", "Download ready in: " + ((System.currentTimeMillis() - startTime) / 1000) + " secs.");
}

catch (IOException e)
{
    Log.e("log_tag", "Error: " + e.toString());
}

}

---

你能发布StackStrace吗？你能发布StackStrace吗？好的，我这样做了，现在它给了我一个错误：error:java.io.FileNotFoundException:/http:/www.wktechnologies.com/shc\u android\u app/data.kml是什么导致http://更改为/http:/？我是说这是一个硬编码的URL。它到底是如何变化的呢？根据我的catch语句，url显示的是以/http://开头的链接，而不是http://Ok，我这样做了，现在它给了我一个错误：error:java.io.FileNotFoundException:/http:/www.wktechnologies.com/shc_android\u app/data.kml是什么导致http://更改为/http:/？我是说这是一个硬编码的URL。它到底是如何变化的呢？根据我的catch语句，url显示的是以/http:/开头的链接，而不是http://