Java “错误”；“未找到文件”；即使在创建文件后也会抛出

我的代码相当长，但基本上，每次用户单击一个按钮时，它都会运行两种方法—从文件中读取对象数组。然后，它将一个新人的详细信息附加到此数组，然后第二个方法写入该文件。第一次，在logcat中，我得到了错误“未找到文件”-这是意料之中的，因为我还没有创建文件。第二次点击，同样的错误。反复出现同样的错误。所以，我推断，有些地方出了问题，因为否则它不会抛出错误“未找到文件”-文件是上次写入时创建的。 我的活动代码：

package com.example.partyorganiser;


import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Arrays;



import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;

public class AddPeople extends Activity {

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


///Addpeople is the activity to add people to an arraylist, which is read and then written back to the file

    ///It will then write this to a file in the internal memory of the device, in  CSV like format.


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_list, menu);
    return true;
}
public void addpeople_action_save(View view) {
    EditText et_addpeople_name = (EditText) findViewById(R.id.addpeople_name);
    EditText et_addpeople_number = (EditText) findViewById(R.id.addpeople_number);
    String person_name = et_addpeople_name.getText().toString();///parses from the EditText to a string.
    String person_number = et_addpeople_number.getText().toString();
    ///Next section is writing the two strings to a internal file, as a CSV format.
    ///eg: Bill, 0123567898
    ///this will actually append the string to an arraylist of strings, before writing it back to the file.
    ArrayList<PeopleDetails> peopledetails_return = Readpeopledetails();///throws error here, presumably, when reading a file that doesn't exist.
    ///but doesn't stop normal program flow....
    PeopleDetails person_details = new PeopleDetails("", "");
    person_details.name = person_name;
    person_details.number = person_number;

    ///need to write arraylists back to file. Will overwrite if exists (contains previous data in arraylist)
    ///or will write a new file if it doesn't exist.
    ///New method(PeopleNumber, PeopleName, Filename)
    ///will write to file.
}
///SORT METHOD:
///Could sort the names and numbers by alphabetical order,

public void addpeople_switchmenu(View view){
    Intent switch_menu = new Intent(this, MenuList.class);
    EditText et_addpeople_name = (EditText) findViewById(R.id.addpeople_name); et_addpeople_name.setText(null);
    EditText et_addpeople_number = (EditText) findViewById(R.id.addpeople_number);et_addpeople_number.setText(null);
    startActivity(switch_menu);
}

public void peopledetails_write(ArrayList<PeopleDetails> peopledetails_file) {
    ////numbers is the arraylist of numbers.
    ///names is the arraylist of names of people.
    ///Written to file like 01235 678 908, Daniel; 01245 645 123, Bob Marley; etc.
    ///Like a CSV file. 
    try{
        FileOutputStream outputstream_people = openFileOutput("PeopleDetailsFile", MODE_PRIVATE);
                OutputStreamWriter osw = new OutputStreamWriter(outputstream_people); 

        String filestring = ""; ///initializes filestring, which is written to the file.
        for(PeopleDetails person : peopledetails_file){
            String person_detail_string = "";
            person_detail_string = person.name + "," + person.number;
            filestring = filestring + person_detail_string + ";";

        }
    }
        catch (IOException e) {
            Log.e("ERROR", e.toString());
    }






    }

public ArrayList<PeopleDetails> Readpeopledetails(){
    String filereadfrom = "";///declares a string to read file contents into. then split into peopledetails.





    ///Initialises two arraylists of string. one for names and one for numer.s will be used like paralell arrays.
    try{
        InputStream filestream = openFileInput("PeopleDetailsFile");
        if (filestream != null){///first time file is not created. Later will be created, when writing back to the file.
            InputStreamReader inputStreamReader = new InputStreamReader(filestream);
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String receiveString = "";
            StringBuilder stringBuilder = new StringBuilder();

            while ( (receiveString = bufferedReader.readLine()) != null ) {
                stringBuilder.append(receiveString);

            }
            filereadfrom = stringBuilder.toString();
            ///using two delimiters: ";" and ","
            ///split based on ";" to get people as a string, put in array
            ///then split all strings in that array, based on "," and place each into the array peopledetails
            String[] parsearray = filereadfrom.split(";");
            ArrayList<PeopleDetails> peopledetails_array = new ArrayList<PeopleDetails>();

                for(String personstring: parsearray){
                    String[] split = personstring.split(",");
                    PeopleDetails peopledetails_unit = new PeopleDetails("", "");
                    peopledetails_unit.name= split[0];
                    peopledetails_unit.number = split[1];
                    peopledetails_array.add(peopledetails_unit);

                      ///neatly initializes and writes to the peopledetails_array in one section. 
            }



            return peopledetails_array; }
    }





        catch(FileNotFoundException e) {
            Log.e("File not found" , e.toString());
            }

        catch(IOException e){
            Log.e("Can't read file" , e.toString());






        }
    return null;



}
public ArrayList<PeopleDetails> sortList(ArrayList<PeopleDetails> list){
    PeopleDetails[] array = (PeopleDetails[]) list.toArray();
    for (int i = 0; i< (array.length - 1) ; i++){
        for (int j = 0; j < (array.length - 1); j++){
            if(array[j].name.compareTo(array[j + 1].name) > 0){
                PeopleDetails transfer = array[j];
                array[j] = array[j + 1];
                array[j + 1] = transfer;

            }
        }///based off the common bubble sort algorithm - easy to implement.
        ///if it was a much much bigger data system, this would be inappropriate, with Order(n**2), 
        ///as it uses two for loops each n times.
    }
    ArrayList<PeopleDetails> returnlist = new ArrayList<PeopleDetails>();
    for(PeopleDetails item : array){
        returnlist.add(item);


    }
    return returnlist;

}

package com.example.partyorganiser；
导入java.io.BufferedReader；
导入java.io.File；
导入java.io.FileNotFoundException；
导入java.io.FileOutputStream；
导入java.io.FileWriter；
导入java.io.IOException；
导入java.io.InputStream；
导入java.io.InputStreamReader；
导入java.io.OutputStreamWriter；
导入java.util.ArrayList；
导入java.util.List；
导入java.util.array；
导入android.os.Bundle；
导入android.app.Activity；
导入android.content.Context；
导入android.content.Intent；
导入android.util.Log；
导入android.view.Menu；
导入android.view.view；
导入android.widget.EditText；
公共类AddPeople扩展活动{
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity\u add\u people）；
}
///Addpeople是将人员添加到arraylist的活动，arraylist将被读取然后写回文件
///然后，它将以类似CSV的格式将其写入设备内部内存中的文件。
@凌驾
公共布尔onCreateOptions菜单（菜单）{
//为菜单充气；这会将项目添加到操作栏（如果存在）。
getMenuInflater（）.充气（R.menu.menu\u列表，菜单）；
返回true；
}
公共void addpeople\u action\u save（视图）{
EditText et_addpeople_name=（EditText）findViewById（R.id.addpeople_name）；
EditText et_addpeople_number=（EditText）findViewById（R.id.addpeople_number）；
String person_name=et_addpeople_name.getText（）.toString（）；///将编辑文本解析为字符串。
字符串person_number=et_addpeople_number.getText（）.toString（）；
///下一节将把这两个字符串作为CSV格式写入一个内部文件。
///例：比尔，0123567898
///这实际上会在将字符串写回文件之前将其附加到字符串的arraylist中。
ArrayList peopledetails_return=Readpeopledetails（）；///在读取不存在的文件时，可能会在此处抛出错误。
///但不会停止正常的程序流。。。。
PeopleDetails person_details=新的PeopleDetails（“，”）；
person\u details.name=person\u name；
person\u details.number=person\u number；
///需要将arraylist写回文件。如果存在，将覆盖（arraylist中包含以前的数据）
///或者，如果不存在，将写入新文件。
///新方法（PeopleNumber、PeopleName、Filename）
///将写入文件。
}
///排序方法：
///可以按字母顺序排列姓名和数字，
public void addpeople\u开关菜单（视图）{
意向开关\菜单=新意向（此，MenuList.class）；
EditText et_addpeople_name=（EditText）findViewById（R.id.addpeople_name）；et_addpeople_name.setText（null）；
EditText et_addpeople_number=（EditText）findViewById（R.id.addpeople_number）；et_addpeople_number.settText（null）；
启动触觉（开关菜单）；
}
public void peopledetails\u write（ArrayList peopledetails\u文件）{
////数字是数字的数组列表。
///姓名是人名的数组列表。
///写进文件中，比如01235678908，丹尼尔；01245645123，鲍勃·马利；等等。
///像一个CSV文件。
试一试{
FileOutputStream outputstream\u people=openFileOutput（“PeopleDetailsFile”，MODE\u PRIVATE）；
OutputStreamWriter osw=新的OutputStreamWriter（outputstream_人）；
String filestring=“”；///初始化写入文件的filestring。
for（PeopleDetails人员：PeopleDetails\u文件）{
字符串person_detail_String=“”；
person\u detail\u string=person.name+“，”+person.number；
filestring=filestring+person_detail_string+“；”；
}
}
捕获（IOE异常）{
Log.e（“ERROR”，e.toString（））；
}
}
公共ArrayList Readpeopledetails（）{
String filereadfrom=“”；///声明要将文件内容读入的字符串。然后拆分为peopledetails。
///初始化字符串的两个ArrayList。一个用于名称，一个用于数字。s将与并行数组一样使用。
试一试{
InputStream filestream=openFileInput（“PeopleDetailsFile”）；
如果（filestream！=null）{///第一次未创建文件。稍后将在写回文件时创建。
InputStreamReader InputStreamReader=新的InputStreamReader（文件流）；
BufferedReader BufferedReader=新的BufferedReader（inputStreamReader）；
字符串receiveString=“”；
StringBuilder StringBuilder=新的StringBuilder（）；
而（（receiveString=bufferedReader.readLine（））！=null）{
stringBuilder.append（receiveString）；
}
filereadfrom=stringBuilder.toString（）；
///使用两个分隔符：；“和”
///基于“；”进行拆分以将人员作为字符串，放入数组中
///然后根据“，”拆分该数组中的所有字符串，并将每个字符串放入数组peopledetails中
字符串[]parsearray=filereadfrom.split（“；”）；
ArrayList peopledetails_array=new ArrayList（）；
for（字符串personstring:parsearray）{
String[]split=personstring.split（“，”）；
PeopleDetails PeopleDetails\u unit=新的PeopleDetails（“，”）；
peopledetails_unit.name=split[0]；
peopledetails_unit.number=拆分[1]；
人物细节_
  ArrayList<PeopleDetails> peopledetails_return = Readpeopledetails()

  InputStream filestream = openFileInput("PeopleDetailsFile");

551     public abstract FileOutputStream openFileOutput(String name, int mode)
552         throws FileNotFoundException;

  FileOutputStream outputstream_people = openFileOutput("PeopleDetailsFile", MODE_PRIVATE);