java - 文件已创建但返回 false

Question

我不明白为什么我们不进入第二个if。我首先检查文件是否存在(不，逻辑)，创建它，然后再次检查，但它仍然返回 false。我试了一个小时才找到问题，我确信这是一个愚蠢的错误。抱歉我的英语不好

代码如下:

package com.example.testcreatefileonclick;

import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Main extends Activity implements android.view.View.OnClickListener{

    Button button;
    Button addTeam;
    Boolean append = true;

    String name = "nomFichier.txt";

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

        button = (Button)findViewById(R.id.button1);
        button.setOnClickListener((OnClickListener) this);
        addTeam = (Button)findViewById(R.id.button2);
        addTeam.setOnClickListener((OnClickListener) this);

    }

    @Override
    public void onClick(View v) {
        try {
            File fichier = new File(name);


            if (!fichier.exists()) {
                System.out.println("File doesn't exists");
            }


            FileOutputStream fOut = openFileOutput(name, MODE_WORLD_READABLE);
            OutputStreamWriter osw = new OutputStreamWriter(fOut); 
            osw.write("text");
            osw.flush();
            osw.close();

            //Why don't we go in this if ?
            if (fichier.exists()) {
                System.out.println("File exists");
            }


        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}

编辑:工作代码

package com.example.testcreatefileonclick;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Main extends Activity implements android.view.View.OnClickListener{

    Button button;
    Button addTeam;
    Boolean append = true;
    String name = "nomFichier.txt";

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

        button = (Button)findViewById(R.id.button1);
        button.setOnClickListener((OnClickListener) this);
        addTeam = (Button)findViewById(R.id.button2);
        addTeam.setOnClickListener((OnClickListener) this);

    }

    @Override
    public void onClick(View v) {
        try {
            String filePath = (this.getFilesDir().getPath().toString());
            File fichier = new File(filePath + name);

            if (!fichier.exists()) {
                System.out.println("File doesn't exists");
            }

            fichier.createNewFile();
            FileWriter file = new FileWriter(filePath + name);
            file.write("text");
            file.flush();
            file.close();

            if (fichier.exists()) {
                System.out.println("File exists");
            }


        } catch (IOException e) {
            System.out.println("Exception");
            e.printStackTrace();
        }
    }
}

Answer 1

尝试替换这个:

FileOutputStream fOut = openFileOutput(name, MODE_WORLD_READABLE);
        OutputStreamWriter osw = new OutputStreamWriter(fOut); 
        osw.write("text");
        osw.flush();
        osw.close();

通过这个:

fichier.createNewFile();
FileWriter file = new FileWriter(name);
file.write("text");
file.flush();
file.close();