android 错误：java.io.filenotfoundexception /proc/net/xt_qtaguid/stats + 打开失败：ENOENT（没有这样的文件或目录）

Question

我正在尝试创建允许用户在输入文件名后保存文件的 android 应用程序，但问题是当用户尝试保存文件时会显示错误消息：

 Caused by: java.io.FileNotFoundException: /proc/net/xt_qtaguid/stats: open failed: ENOENT (No such file or directory)

然后它保存为 null.txt

的文件

如何解决这个错误？？？

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;
    }

}

Answer 1

它会引发错误，因为您尝试将文件保存在不存在的目录中。我运行了您的代码并使用断点检查字符串fileName 中的值。

从下面的屏幕截图中，您可以看到它是一个无效的目录，并且问题出在哪里。您可能想要更改目录。

[编辑]

更改设置文件名的方式。

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

现在，fileName 将具有当前日期 + 用户输入的文本。

例如，文件名将是2013-12-26-18-51-26-hello.txt

另外，请确保您已添加权限<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />