FTPClient应用程序

我正在使用ftp客户端项目。我在logcat中有以下错误。FTPClient应用程序

09-25 19:51:26.884: D/MyFTPClient(9521): Connection Success 
09-25 19:51:27.424: W/dalvikvm(9521): dvmFindClassByName rejecting 'UNIX Type: L8' 
09-25 19:51:32.309: W/dalvikvm(9521): threadid=12: thread exiting with uncaught exception (group=0x40a89228) 
09-25 19:51:32.319: E/AndroidRuntime(9521): FATAL EXCEPTION: AsyncTask #1 
09-25 19:51:32.319: E/AndroidRuntime(9521): java.lang.RuntimeException: An error occured while executing doInBackground() 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at android.os.AsyncTask$3.done(AsyncTask.java:278) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at java.util.concurrent.FutureTask.setException(FutureTask.java:124) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at java.util.concurrent.FutureTask.run(FutureTask.java:137) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at java.lang.Thread.run(Thread.java:864) 
09-25 19:51:32.319: E/AndroidRuntime(9521): Caused by: java.lang.NullPointerException 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at com.example.ftpclient.MyFTPClient.listftpitems(MyFTPClient.java:112) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at com.example.ftpclient.MyFTPClient$connection_test.doInBackground(MyFTPClient.java:69) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at com.example.ftpclient.MyFTPClient$connection_test.doInBackground(MyFTPClient.java:1) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at android.os.AsyncTask$2.call(AsyncTask.java:264) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305) 
09-25 19:51:32.319: E/AndroidRuntime(9521):  ... 5 more 
09-25 19:51:32.399: I/Adreno200-EGLSUB(9521): <ConfigWindowMatch:1991>: Format RGBA_8888.

我的代码是

protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.showfiles); 

    lv = (ListView) findViewById(R.id.listview1); 
    new connection_test().execute(""); 


    } 

private class connection_test extends AsyncTask<String, Void,ArrayList<String>> { 
     ArrayList<String> temparrlist = new ArrayList<String>(); 
     @Override 
     protected void onPreExecute(){ 
      dialog = ProgressDialog.show(MyFTPClient.this,null,"Please wait..."); 

     } 

     @Override 
     protected ArrayList<String> doInBackground(String... connection) { 

       temparrlist=listftpitems(); 
       return temparrlist; 

     } 

     @Override 
     protected void onPostExecute(ArrayList<String> result) { 
      dialog.dismiss(); 
      ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(MyFTPClient.this,android.R.layout.simple_list_item_1,result); 
      lv.setAdapter(arrayAdapter); 

     } 
    } 

public ArrayList<String> listftpitems(){ 

    try { 
     //ArrayList<String> arrayList = new ArrayList<String>(); 
      mFTPClient = new FTPClient(); 
      mFTPClient.connect("ftp.ftpaddress",21); 


       boolean status = mFTPClient.login("userid", "password"); 
       mFTPClient.setFileType(FTP.BINARY_FILE_TYPE); 
       mFTPClient.enterLocalPassiveMode(); 

       if (status == true) { 
        Log.d(TAG, "Connection Success"); 

       } else { 

        Log.d(TAG, "Connection failed"); 
       } 

      } catch (Exception e) { 
      e.printStackTrace(); 
     } 

     final FTPFile[] files; 
     try { 
      files = mFTPClient.listFiles("/public_html/"); 
      for (FTPFile file : files) { 
       String details = file.getName(); 
       arrayList.add(details); 
       Log.d(TAG, details); 
      } 
     }catch (IOException e1) { 
      e1.printStackTrace(); 
     } 

    return arrayList; 
    }

来源

2013-09-25 Nishad

变量arrayList可当你试图将项目添加到它尚未instaciated。在arrayList.add(details);。尝试在调用asynctask之前实例化这个变量。

来源

2013-09-26 08:27:52 KLiFF

你有'arrayList = new ArrayList （）;'某处？ – KLiFF

谢谢你，先生你是正确的代码工作。 – Nishad

很高兴听到！ – KLiFF

FTPClient应用程序

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