Android 如何从服务器下载文件找不到错误文件？

您能告诉我如何从服务器下载文件吗？我正在获取错误填充未找到错误

07-30 17:10:28.849: W/System.err(14900): java.io.FileNotFoundException: /testnaveen: open failed: EROFS (Read-only file system)
07-30 17:10:28.849: W/System.err(14900):    at libcore.io.IoBridge.open(IoBridge.java:409)
07-30 17:10:28.849: W/System.err(14900):    at java.io.FileOutputStream.<init>(FileOutputStream.java:88)
07-30 17:10:28.849: W/System.err(14900):    at java.io.FileOutputStream.<init>(FileOutputStream.java:128)
07-30 17:10:28.849: W/System.err(14900):    at java.io.FileOutputStream.<init>(FileOutputStream.java:117)
07-30 17:10:28.849: W/System.err(14900):    at com.mobilecem.atms.GlobalFunction.downloadFileFromServer(GlobalFunction.java:147)

我叫两个方向，但热相同的错误为什么

GlobalFunction.downloadFileFromServer("test", "http://www.example.com/inputParameters.js");
GlobalFunction.downloadFileFromServer( new File(Activity.this.getFilesDir(),"www").getAbsolutePath(), "url");

如果您使用的是Honeycom或更高版本，则需要使用来调用与网络相关的操作

---

使用下载管理器。

下载管理器的优点：

如果连接丢失，它会自动重试下载

它负责工作线程，即后台线程

它在导航栏中显示您的下载状态和进度状态

package com.example.testing;
import android.app.Activity;
import android.app.DownloadManager;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;

public class FileDownloading extends Activity
{

@Override
protected void onCreate(Bundle savedInstanceState)
{
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    startDownload("http://www.example.com/inputParameters.js","inputParameters.js");
}
public void startDownload(String url ,String fileName)
{
    Log.d("Download Url", url);
    DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
    request.setTitle("Your File Name");
    request.setDescription(fileName+" is downloading..");
    request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName);
    DownloadManager downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE); 
    long downloadID = downloadManager.enqueue(request); 
}
 }

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不要忘记在

manifest.xml中使用Internet和存储权限

确保您的文件不是只读的。已在清单中提供写入外部存储权限？已写入menifest文件。请从服务器下载文件，确保文件名正确，并将其上载到服务器上。如果您点击类似按钮，则会将其上载到服务器上，因为有文件。但文件名是什么？我提到任何东西，你必须重写它才能使用AsyncTask

package com.example.testing;
import android.app.Activity;
import android.app.DownloadManager;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;

public class FileDownloading extends Activity
{

@Override
protected void onCreate(Bundle savedInstanceState)
{
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    startDownload("http://www.example.com/inputParameters.js","inputParameters.js");
}
public void startDownload(String url ,String fileName)
{
    Log.d("Download Url", url);
    DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
    request.setTitle("Your File Name");
    request.setDescription(fileName+" is downloading..");
    request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName);
    DownloadManager downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE); 
    long downloadID = downloadManager.enqueue(request); 
}
 }