java - 读取 txt 文件时出错

Question

当我尝试读取保存在手机外部存储上的文件时，我的代码中出现此错误:

java.io.FileNotFoundException: shopping.txt: open failed: ENOENT (No such file or directory)

我可以成功地将数据写入该文件，我已经做了很多次了。但是，我无法通过提供完整路径或通过其他方法来读取同一文件。

代码写入并保存成功:

File path  = new File(this.getFilesDir().getPath());
            String value = "vegetables";
            // File output = new File(path + File.separator + fileName);
            File output = new File(getApplicationContext().getExternalFilesDir(null),"shopping.txt");
            try {
                FileOutputStream fileout = new FileOutputStream(output.getAbsolutePath());
                OutputStreamWriter outputWriter=new OutputStreamWriter(fileout);
                outputWriter.write(value);
                outputWriter.close();
                //display file saved message
               // Toast.makeText(getBaseContext(), "File saved successfully!",
                 //       Toast.LENGTH_LONG).show();
                Toast.makeText(MainActivity.this,String.valueOf(output),Toast.LENGTH_LONG).show();
                Log.d("MainActivity", "Chemin fichier = [" + output + "]");
            }
            catch (IOException e) {
                Log.e("Exception", "File write failed: " + e.toString());
            }
        }

编写的代码使我的应用程序崩溃:

try
            {
                File gFile;
                FileInputStream fis = new FileInputStream (new File("shopping.txt"));
                //FileInputStream fis = openFileInput("/storage/emulated/0/Android/data/com.example.namour.shoppinglist/files/shopping.txt");
                BufferedReader reader = new BufferedReader(new InputStreamReader(fis));
                String line = null, input="";
                while ((line = reader.readLine()) != null)
                    input += line;

                Toast.makeText(MainActivity.this,line,Toast.LENGTH_LONG).show();
                reader.close();
                fis.close();
                Toast.makeText(MainActivity.this,"Read successful",Toast.LENGTH_LONG).show();
                //return input;
            }
            catch (IOException e)

            {
                Log.e("Exception", "File read failed: " + e.toString());
                //toast("Error loading file: " + ex.getLocalizedMessage());

            }

我做错了什么？当然，不是权限问题，因为我可以成功写入。

非常感谢您的帮助。

Answer 1

您错过了指定正确的路径。您正在当前工作目录(运行时)中查找名为 shopping.txt 的文件。使用正确的路径创建一个新的 File 对象，它将起作用:
文件输入 = new File(getApplicationContext().getExternalFilesDir(null),"shopping.txt");。您可以通过编写重用您的对象。