the output is null i am trying to save a file in the sd of the emulator of the phone by asking the user to enter the file name

Question

i ma trying to save file on the emulator or the phone by asking the user to enter the file name using the alert dialog and then the system will add to the file name the current date and time but the problem is that the system save the file name by null.txt how to fix this problem ???

SignSActivity.java

package com.devleb.idapp;

import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.DatePickerDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Bundle;
import android.os.Environment;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class SignSoldgerActivity extends Activity {

    EditText edit_txt_note;
    final Context context = this;
    // attribute for the date picker

    public String fileName;
    String userinputResult;

    Button btndatePicker, btn_save_soldger;
    TextView txtatePicker;
    int year, monthofyear, dayofmonth;
    Calendar cal = Calendar.getInstance();
    DateFormat dt = DateFormat.getInstance();

    DatePickerDialog.OnDateSetListener dpd;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sign_soldger);

        edit_txt_note = (EditText) findViewById(R.id.editTxtNote);

        btndatePicker = (Button) findViewById(R.id.btnDateTimePicker);
        btndatePicker.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                new DatePickerDialog(SignSoldgerActivity.this, dpd, cal
                        .get(Calendar.YEAR), cal.get(Calendar.MONTH), cal
                        .get(Calendar.DAY_OF_MONTH)).show();

            }
        });

        txtatePicker = (TextView) findViewById(R.id.txtDate);

        dpd = new DatePickerDialog.OnDateSetListener() {

            @Override
            public void onDateSet(DatePicker view, int year, int monthOfYear,
                    int dayOfMonth) {
                // TODO Auto-generated method stub
                cal.set(Calendar.YEAR, year);
                cal.set(Calendar.MONTH, monthOfYear);
                cal.set(Calendar.DAY_OF_MONTH, dayOfMonth);

                txtatePicker.setText(new StringBuilder().append(year + "/")
                        .append(monthOfYear + "/").append(dayOfMonth));
            }
        };

        btn_save_soldger = (Button) findViewById(R.id.btnSaveSoldger);
        btn_save_soldger.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {

                // / for creating a dialog
                LayoutInflater li = LayoutInflater.from(context);
                View promptsView = li.inflate(R.layout.prompts, null);

                AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
                        context);

                // set prompts.xml to alertdialog builder
                alertDialogBuilder.setView(promptsView);

                final EditText userInput = (EditText) promptsView
                        .findViewById(R.id.editTextDialogUserInput);

                // set dialog message
                alertDialogBuilder
                        .setCancelable(false)
                        .setPositiveButton("OK",
                                new DialogInterface.OnClickListener() {
                                    public void onClick(DialogInterface dialog,
                                            int id) {
                                        // get user input and set it to result
                                        // edit text
                                        userinputResult = userInput.getText()
                                                .toString();

                                        SimpleDateFormat formatter = new SimpleDateFormat(
                                                "yyyy/MM/dd\\HH:mm:ss");
                                        Date now = new Date();
                                        fileName = formatter.format(now) + "/"
                                                + userinputResult;

                                        saveFile(fileName);
                                        txtatePicker.setText(fileName);
                                    }
                                })
                        .setNegativeButton("Cancel",
                                new DialogInterface.OnClickListener() {
                                    public void onClick(DialogInterface dialog,
                                            int id) {
                                        dialog.cancel();
                                    }
                                });

                // create alert dialog
                AlertDialog alertDialog = alertDialogBuilder.create();

                // show it
                alertDialog.show();

            }

        });

    }

    // / for saving the file on the SD

    public void saveFile(String fileName) {
        try {
            String sdPath = Environment.getExternalStorageDirectory()
                    .getAbsolutePath() + "/" + fileName + ".txt";

            File myFile = new File(sdPath);
            myFile.createNewFile();

            Toast.makeText(getBaseContext(), "the second step in saving file",
                    Toast.LENGTH_SHORT).show();

            FileOutputStream fOut = new FileOutputStream(myFile);
            OutputStreamWriter myOutWriter = new OutputStreamWriter(fOut);

            // append or write
            myOutWriter.append(edit_txt_note.getText());
            myOutWriter.close();
            fOut.close();
            edit_txt_note.setText("");
            Toast.makeText(getBaseContext(), "Done Writing SD" + fileName,
                    Toast.LENGTH_SHORT).show();

        } catch (Exception e) {

            Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT)
                    .show();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.sign_soldger, menu);
        return true;
    }

}

Manifest file

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.devleb.idapp"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.devleb.idapp.SplashScreen"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.devleb.idapp.SecondActivity"
            android:label="@string/title_activity_second" >
            <intent-filter>
                <action android:name="com.devleb.idapp.CLEARSCREEN" />

                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.devleb.idapp.SignSoldgerActivity"
            android:label="@string/title_activity_sign" >
        </activity>
        <activity
            android:name="com.devleb.idapp.SignOfficerActivity"
            android:label="@string/title_activity_sign_officer" >
        </activity>
        <activity
            android:name="com.devleb.idapp.RegisterActivity"
            android:label="@string/title_activity_register" >
        </activity>
    </application>

</manifest>

Log Cat

12-24 13:27:09.918: E/AndroidRuntime(1531): FATAL EXCEPTION: main
12-24 13:27:09.918: E/AndroidRuntime(1531): java.lang.RuntimeException: Unable to instantiate application android.app.Application: java.lang.NullPointerException
12-24 13:27:09.918: E/AndroidRuntime(1531):     at android.app.LoadedApk.makeApplication(LoadedApk.java:482)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at android.app.ActivityThread.handleBindApplication(ActivityThread.java:3938)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at android.app.ActivityThread.access$1300(ActivityThread.java:123)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1185)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at android.os.Handler.dispatchMessage(Handler.java:99)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at android.os.Looper.loop(Looper.java:137)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at android.app.ActivityThread.main(ActivityThread.java:4424)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at java.lang.reflect.Method.invokeNative(Native Method)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at java.lang.reflect.Method.invoke(Method.java:511)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at dalvik.system.NativeStart.main(Native Method)
12-24 13:27:09.918: E/AndroidRuntime(1531): Caused by: java.lang.NullPointerException
12-24 13:27:09.918: E/AndroidRuntime(1531):     at android.app.LoadedApk.initializeJavaContextClassLoader(LoadedApk.java:362)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at android.app.LoadedApk.getClassLoader(LoadedApk.java:305)
12-24 13:27:09.918: E/AndroidRuntime(1531):     at android.app.LoadedApk.makeApplication(LoadedApk.java:474)
12-24 13:27:09.918: E/AndroidRuntime(1531):     ... 11 more

Have you tried debugging your code and printing the filename ? — GrIsHu, Dec 24 '13 at 10:48
i tried your solution but still when i click save and before i enter the file name the system save the file name as null.txt — user3006788, Dec 24 '13 at 10:50

score 0 · Answer 1 · answered Dec 24 '13 at 10:52

You getting file name inside OK of Dialog so that you need to save your file only if your click OK. Try this,

@Override
    public void onClick(View arg0) {

        // / for creating a dialog
        LayoutInflater li = LayoutInflater.from(context);
        View promptsView = li.inflate(R.layout.prompts, null);

        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
                context);

        // set prompts.xml to alertdialog builder
        alertDialogBuilder.setView(promptsView);

        final EditText userInput = (EditText) promptsView
                .findViewById(R.id.editTextDialogUserInput);

        // set dialog message
        alertDialogBuilder
                .setCancelable(false)
                .setPositiveButton("OK",
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog,
                                    int id) {
                                // get user input and set it to result
                                // edit text
                                String userinputResult = userInput
                                        .getText().toString();

                                SimpleDateFormat formatter = new SimpleDateFormat(
                                        "yyyy/MM/dd\\HH:mm:ss");
                                Date now = new Date();
                                fileName = formatter.format(now) + "//"
                                        + userinputResult;

                                txtatePicker.setText(fileName);
                                // / for saving the file on the SD
                                writeFile(fileName);
                            }
                        })
                .setNegativeButton("Cancel",
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog,
                                    int id) {
                                dialog.cancel();
                            }
                        });

        // create alert dialog
        AlertDialog alertDialog = alertDialogBuilder.create();

        // show it
        alertDialog.show();



    }




    private void writeFile(String fileName){
         try {
                String sdPath = Environment.getExternalStorageDirectory()
                        .getAbsolutePath() + "/" + fileName + ".txt";

                File myFile = new File(sdPath);
                myFile.createNewFile();

                Toast.makeText(getBaseContext(),
                        "the second step in saving file",
                        Toast.LENGTH_SHORT).show();

                FileOutputStream fOut = new FileOutputStream(myFile);
                OutputStreamWriter myOutWriter = new OutputStreamWriter(
                        fOut);

                // append or write
                myOutWriter.append(edit_txt_note.getText());
                myOutWriter.close();
                fOut.close();
                edit_txt_note.setText("");
                Toast.makeText(getBaseContext(),
                        "Done Writing SD" + fileName, Toast.LENGTH_SHORT)
                        .show();

            } catch (Exception e) {

                Toast.makeText(getBaseContext(), e.getMessage(),
                        Toast.LENGTH_SHORT).show();
            }
    }

i tried your answer and now it give me a new error: **open failed:ENOENT(no such file or directory)** and the system did not save the file — user3006788, Dec 24 '13 at 11:09
Did you give `WRITE_EXTERNAL_STORAGE` permission, and do you have sdcard? — SathishKumar, Dec 24 '13 at 11:14
Check this, http://stackoverflow.com/questions/8152125/how-to-create-text-file-and-insert-data-to-that-file-on-android — SathishKumar, Dec 24 '13 at 11:22
yes i have this permission and i have sd Card but still the same error — user3006788, Dec 24 '13 at 11:25

score 0 · Answer 2 · answered Dec 24 '13 at 10:59

0

Create a separate method of your save file code and pass the Filename as parameter from your dialog ok button click as below:

Create method of save file code.

 public void saveFileinSDCard(String filename)
 {
    try {
        String sdPath = Environment.getExternalStorageDirectory()
                .getAbsolutePath() + "/" + filename+ ".txt";

        File myFile = new File(sdPath);
        myFile.createNewFile();

        Toast.makeText(getBaseContext(),
                "the second step in saving file",
                Toast.LENGTH_SHORT).show();

        FileOutputStream fOut = new FileOutputStream(myFile);
        OutputStreamWriter myOutWriter = new OutputStreamWriter(
                fOut);

        // append or write
        myOutWriter.append(edit_txt_note.getText());
        myOutWriter.close();
        fOut.close();
        edit_txt_note.setText("");
        Toast.makeText(getBaseContext(),
                "Done Writing SD" + fileName, Toast.LENGTH_SHORT)
                .show();

    } catch (Exception e) {

        Toast.makeText(getBaseContext(), e.getMessage(),
                Toast.LENGTH_SHORT).show();
    }
 }

Call the above method in your ok button click as below:

     alertDialogBuilder
            .setCancelable(false)
            .setPositiveButton("OK",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog,
                                int id) {
                            // get user input and set it to result
                            // edit text
                            String userinputResult = userInput
                                    .getText().toString();

                            SimpleDateFormat formatter = new SimpleDateFormat(
                                    "yyyy/MM/dd\\HH:mm:ss");
                            Date now = new Date();
                            fileName = formatter.format(now) + "//"
                                    + userinputResult;

                             saveFileinSDCard(fileName); //Call the method here.

                            txtatePicker.setText(fileName);
                        }
                    })

answered Dec 24 '13 at 10:59

GrIsHu

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i tried your answer and now it give me a new error: **open failed:ENOENT(no such file or directory)** and the system did not save the file – user3006788 Dec 24 '13 at 11:11
@user3006788 have you add permission for write and read external storage in manifest file?? – Piyush Dec 24 '13 at 11:14
@user3006788 Remove a one `/` slash from your file name in line `fileName = formatter.format(now) + "//"+ userinputResult;` and change it to `fileName = formatter.format(now) + "/"+ userinputResult;` and then check – GrIsHu Dec 24 '13 at 11:16
@ GrlsHu i add the log Cat that display the error as Null Exception where is the error ?? – user3006788 Dec 24 '13 at 11:34
@user3006788 Have you Created Skeleton Application Class?? – Piyush Dec 24 '13 at 11:35
@user3006788 The problem is because if you have created Application class then you must add to it in your manifest file with your app package name – Piyush Dec 24 '13 at 11:37
@ Piyush Gupta what is the Skeleton Application Class and no i did not – user3006788 Dec 24 '13 at 11:37
@user3006788 Is your all Operation Performed in your "SecondActivity"?? – Piyush Dec 24 '13 at 11:40
Remove this line in your manifest file `` and then try – GrIsHu Dec 24 '13 at 11:43
@user3006788 As per **GrIsHu** guideline remove that line: – Piyush Dec 24 '13 at 11:44
@user3006788 Do one thing comment Intent-Filter for SecondAcivity and after that run it – Piyush Dec 24 '13 at 11:58
@GrIsHu I need your help in some case – Piyush Dec 24 '13 at 13:23
@ GrIsHu it still the same error from 2 days anyone know how to fix it?? – user3006788 Dec 26 '13 at 10:20
@user3006788 Can you show me your whole code so that i can understand and resolve your issue? – GrIsHu Dec 26 '13 at 10:21

the output is null i am trying to save a file in the sd of the emulator of the phone by asking the user to enter the file name

SignSActivity.java

Manifest file

Log Cat

2 Answers2