Android n00b试图找出文件服务器上传。我尝试使用storeFile中的FTPClient方法将文件上传到Android中的FTP服务器，在Galaxy Nexus上进行测试时遇到了很多麻烦。两个问题。首先，它非常非常缓慢地运行 - 在代码移动之前，对于几个字节的文件只需要一分钟或更长时间（因此我的显示器在完成运行之前经常进入休眠状态）。其次，完成后服务器上没有文件到达。但是代码确实继续运行，据我所知，我没有得到任何明确的错误消息告诉我一些错误。但第三，在所有这些（和注销）之后，它给了我一个 NullPointerException 并中止了活动。
（同样是第四个问题NetworkInfo.getActiveNetworkInfo()似乎总是回到连接，即使我没有连接，但这似乎是无关的，我想专注于更大的问题。）
这是我的代码：
[Reuse.logIt是我用来打印到logcat的方法，printToUI打印到显示器上的setText。你可以告诉我，我正试图给自己一些路标来弄清楚发生了什么。]
public void uploadFile(String filename, File theFile)
{
Reuse.logIt(TAG, "UploadFile did run."); // test that at least
FTPClient theClient = new FTPClient();
// It's probably insecure to do it this way, but first I just want to make it work.
final String theSite = [the name of my site];
String username = [my username];
String password = [my password];
// get network status
Context theContext = getApplicationContext();
ConnectivityManager cMgr = (ConnectivityManager)theContext.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cMgr.getActiveNetworkInfo();
String beginStatus = netInfo.getState().toString();
// always says CONNECTED whether we're connected or not.
String networkStatus = "Network status = "+beginStatus;
Reuse.logIt(TAG, networkStatus);
// pass the network status where it can be displayed in a different window's text.
Brouillon instance = (Brouillon) theContext;
instance.setDataResult(networkStatus);
if (beginStatus == "CONNECTED")
// If we don't have a network connection, don't upload the file.
{
try
{
theClient.connect(theSite);
// When login succeeds, the login method returns true.
boolean login = theClient.login(username, password);
if (login)
{
// success!
Reuse.logIt(TAG, "Logged in successfully to "+theSite+"!");
printToUI("ftp_connect", "Logged in successfully to "+theSite+"!");
Reuse.logIt(TAG, "The code does continue after logging in.");
// Now upload the file.
String ftpPath = "/brouillon/";
String filenameOnFTP = ftpPath+filename;
Reuse.logIt(TAG, "It defined the variables.");
FileInputStream fis = new FileInputStream(theFile);
Reuse.logIt(TAG, "It created the FileInputStream too.");
theClient.storeFile(filenameOnFTP, fis);
Reuse.logIt(TAG, "We created a file called "+filenameOnFTP+".");
printToUI("upload","We created a file called "+filenameOnFTP+".");
}
else
{
Reuse.logIt(TAG, "Could not connect to "+theSite+".");
printToUI("ftp_connect","Could not connect to "+theSite+".");
}
boolean logout = theClient.logout();
if (logout)
{
Reuse.logIt(TAG, "Logged out successfully.");
printToUI("loggedout","Logged out successfully.");
}
else
{
Reuse.logIt(TAG, "Logout failed!");
printToUI("loggedout","Logout failed!");
}
}
catch(IOException e)
{
e.printStackTrace();
Reuse.logIt(TAG, "Got error message "+e.toString()+".");
}
}
else
{
// For testing purposes, abort the program if not connected. Can change that later.
Reuse.logIt(TAG, "beginStatus was not CONNECTED!");
System.exit(0);
}
}
}
这是我的logcat。 （在错误模式下设置。如果给出一个更详细的模式会有所帮助，我很乐意这样做，但我一开始就把它留下来，因为它会使这个帖子真的很长。）
03-29 13:08:13.400: E/SyncStatus(8764): Sync button pushed.
03-29 13:08:13.400: E/SyncStatus(8764): File created and closed.
03-29 13:08:13.400: E/SyncStatus(8764): UploadFile did run.
03-29 13:08:13.431: E/SyncStatus(8764): Network status = CONNECTED
03-29 13:08:14.556: E/SyncStatus(8764): Logged in successfully to [site name]!
03-29 13:08:14.556: E/SyncStatus(8764): The code does continue after logging in.
03-29 13:08:14.556: E/SyncStatus(8764): It defined the variables.
03-29 13:08:14.556: E/SyncStatus(8764): It created the FileInputStream too.
03-29 13:10:32.283: E/wpa_supplicant(452): android_priv_cmd: failed to issue private commands
03-29 13:11:28.603: E/SyncStatus(8764): We created a file called /brouillon/filename.txt.
03-29 13:11:28.705: E/SyncStatus(8764): Logged out successfully.
03-29 13:11:28.713: E/AndroidRuntime(8764): FATAL EXCEPTION: main
03-29 13:11:28.713: E/AndroidRuntime(8764): java.lang.NullPointerException
03-29 13:11:28.713: E/AndroidRuntime(8764): at com.loveofallwisdom.brouillon.SyncStatus$2.run(SyncStatus.java:174)
03-29 13:11:28.713: E/AndroidRuntime(8764): at android.os.Handler.handleCallback(Handler.java:725)
03-29 13:11:28.713: E/AndroidRuntime(8764): at android.os.Handler.dispatchMessage(Handler.java:92)
03-29 13:11:28.713: E/AndroidRuntime(8764): at android.os.Looper.loop(Looper.java:137)
03-29 13:11:28.713: E/AndroidRuntime(8764): at android.app.ActivityThread.main(ActivityThread.java:5041)
03-29 13:11:28.713: E/AndroidRuntime(8764): at java.lang.reflect.Method.invokeNative(Native Method)
03-29 13:11:28.713: E/AndroidRuntime(8764): at java.lang.reflect.Method.invoke(Method.java:511)
03-29 13:11:28.713: E/AndroidRuntime(8764): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
03-29 13:11:28.713: E/AndroidRuntime(8764): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
03-29 13:11:28.713: E/AndroidRuntime(8764): at dalvik.system.NativeStart.main(Native Method)
03-29 13:11:38.931: E/wpa_supplicant(452): android_priv_cmd: failed to issue private commands
答案 0 :(得分：5)
请以这种方式尝试：
public static String uploadOrder(String fileName)
{
String m;
FTPClient con = null;
m = "Conn failed";
try
{
con = new FTPClient();
con.connect("xxx.xxx.210.176");
//username and password for ftp server
if (con.login("ftpxxx@xxxxx", "pass"))
{
con.enterLocalPassiveMode();//passive mode - IMPORTANT
con.setFileType(FTP.ASCII_FILE_TYPE);//only for txt file ACII mode, for rest binary mode
String data = Environment.getExternalStorageDirectory().getPath() +"/"+ fileName; //data location
FileInputStream in = new FileInputStream(data);
File f = new File(data);
con.changeWorkingDirectory("xxxxxx");//
if(con.changeWorkingDirectory("Orders"))//
{
Log.i("FTP","Got into directory");
}
if(!con.changeWorkingDirectory(MainPage.fb_id))//
{
in.close();
con.logout();
con.disconnect();
return m;
}
if(con.storeFile(fileName, in))
{
m = "Upload success!";
}
if(!f.exists()) m = "File not exists.";
in.close();
//logging out
con.logout();
con.disconnect();
}
else
{
m = "Unsuccessful";
}
}
catch (Exception e)
{
m = e.getMessage();
}
return m;
}