我正在开发 android 项目来测试上传或下载文件的 FTP 功能。这是我基于本教程的第一次尝试代码：
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
try {
SimpleFTP ftp = new SimpleFTP();
// Connect to an FTP server on port 21.
ftp.connect("ftp.olympe-network.com", 21, "username", "password");
// Set binary mode.
ftp.bin();
// Change to a new working directory on the FTP server.
ftp.cwd("web");
// Upload some files.
ftp.stor(new File("shirt.jpg"));
//ftp.stor(new File("comicbot-latest.png"));
// You can also upload from an InputStream, e.g.
ftp.stor(new FileInputStream(new File("shirt.jpg")), "shirt.jpg");
/*ftp.stor(someSocket.getInputStream(), "blah.dat");
*/
// Quit from the FTP server.
ftp.disconnect();
}
catch (IOException e) {
// Jibble.
}
}
我的 shirt.jpg 文件存储在主项目文件夹中。我使用的是模拟器而不是物理设备。我的日志中没有错误，但文件没有上传。
然后，我改用另一种方法：
private void loadLogs() {
//radBtn.addView(null);
new processTask().execute();
}
private class processTask extends AsyncTask<String, Void, Void>{
private ProgressDialog Dialog = new ProgressDialog(activitiMain.this);
private TextView log;
private Spinner s;
protected void onPreExecute() {
Dialog.setMessage("Loading...");
Dialog.show();
}
@Override
protected Void doInBackground(String... arg0) {
FTPClient client = new FTPClient();
try {
SharedPreferences myPref = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
String ipaddr = myPref.getString("etServer", "");
String port= myPref.getString("port", "21");
String logFile= myPref.getString("logfname", "error_log");
String filePath= myPref.getString("path", "/public_html");
String uname= myPref.getString("uname", "");
String pass= myPref.getString("pass", "");
client.connect(ipaddr,21);
client.enterLocalPassiveMode();
boolean login = client.login(uname, pass);
client.changeWorkingDirectory(filePath);
System.out.println(client.printWorkingDirectory());
BufferedReader reader = null;
String line = null;
sv = new ScrollView(activitiMain.this);
sv.setLayoutParams(LP_FF);
LinearLayout loglay = new LinearLayout(activitiMain.this);
loglay.setOrientation( LinearLayout.VERTICAL ); //FTPFile[] ftpFiles = client.listFiles();
FTPFile[] ftpFiles = client.listFiles();
ArrayList<String> name = new ArrayList<String>();
ArrayAdapter <CharSequence> adapter =new ArrayAdapter <CharSequence> (getBaseContext(), android.R.layout.simple_spinner_item );
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
adapter.add("Select File");*/
//s = new (Spinner)findViewById(R.id.Spinner01);
s = new Spinner(activitiMain.this);
for (int i = 0; i < ftpFiles.length; i++) {
String fname =ftpFiles[i].getName();
Log.i("FTP", "File " +i +" : "+fname);
name.add(fname);
long length = ftpFiles[i].getSize();
//adapter2.add(ftpFiles[i].getName());
//String readableLength = FileUtils.byteCountToDisplaySize( length );
///System.out.println( name + ":\t\t" + readableLength );
}
//String [] strArray =null;
//strArray.toArray(name);
String [] files = name.toArray(new String[name.size()]);
@SuppressWarnings("unchecked")
ArrayAdapter<Object> adapter2 = new ArrayAdapter<Object>(getApplicationContext(), android.R.layout.simple_spinner_item,files);
adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
s.setAdapter(adapter2);
loglay.addView(s);
Log.i("Files", ftpFiles.toString());
for (FTPFile ftpFile : ftpFiles) {
String fileName = ftpFile.getName();
if (fileName.equals(logFile)){
try {
InputStream stream = client.retrieveFileStream(fileName);
reader = new BufferedReader(new InputStreamReader(stream, "UTF-8"));
//line = reader.readLine();
while ((line = reader.readLine())!= null && line.trim().length()>0) {
//System.out.println(line);
log = new TextView(activitiMain.this);
String trail = line;
log.setTextColor(Color.GREEN);
log.setPadding(10, 5, 0, 5);
log.setText(trail);
loglay.addView(log);
}
sv.addView(loglay);
} finally {
if (reader != null) try { reader.close(); } catch (IOException logOrIgnore) {}
}
}
}
client.logout();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
client.disconnect();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
protected void onPostExecute(Void unused) {
Dialog.dismiss();
setContentView(sv);
}
在我的首选项屏幕中，我指定了 ftp 服务器参数，但我的 logcat 中也出现错误：
05-27 18:36:38.237: ERROR/AndroidRuntime(585): FATAL EXCEPTION: main
05-27 18:36:38.237: ERROR/AndroidRuntime(585): java.lang.NullPointerException
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at android.view.ViewGroup.addViewInner(ViewGroup.java:1969)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at android.view.ViewGroup.addView(ViewGroup.java:1865)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at android.view.ViewGroup.addView(ViewGroup.java:1845)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:217)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:207)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at android.app.Activity.setContentView(Activity.java:1658)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at com.sam.remote.activitiMain$processTask.onPostExecute(activitiMain.java:160)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at com.sam.remote.activitiMain$processTask.onPostExecute(activitiMain.java:1)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at android.os.AsyncTask.finish(AsyncTask.java:417)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at android.os.AsyncTask.access$300(AsyncTask.java:127)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at android.os.Handler.dispatchMessage(Handler.java:99)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at android.os.Looper.loop(Looper.java:123)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at android.app.ActivityThread.main(ActivityThread.java:4627)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at java.lang.reflect.Method.invokeNative(Native Method)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at java.lang.reflect.Method.invoke(Method.java:521)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-27 18:36:38.237: ERROR/AndroidRuntime(585): at dalvik.system.NativeStart.main(Native Method)