java.io.filenotfoundexception 尝试从不同文件写入现有文件

Question

我在一个 Activity 的内部存储器中创建了一个文件，并想在下一个 Activity 中再次写入它，但我收到了这个错误。在第一个 Activity 中:

String id_file = "tt_id";
String key_file = "tt_key";
FileOutputStream outputStream1;
FileOutputStream outputStream2;
try {
   outputStream1 = openFileOutput(id_file, Context.MODE_PRIVATE);
   outputStream2 = openFileOutput(key_file, Context.MODE_PRIVATE);
   outputStream1.write(id.getBytes());
   outputStream2.write(key.getBytes());
   outputStream1.close();
   outputStream2.close();

但是在第二个 Activity 中:

FileOutputStream outputStream1;
FileOutputStream outputStream2;
String id="dfg";
String key="khdfks";
    outputStream1 = openFileOutput("tt_id",Context.MODE_PRIVATE);
    outputStream2 = openFileOutput("tt_key", Context.MODE_PRIVATE);
outputStream1.write(id.getBytes());
outputStream2.write(key.getBytes());
outputStream1.close();
outputStream2.close();

我刚刚开始开发 Android 应用程序，因此非常感谢您的帮助。提前谢谢你

Answer 1

我认为您需要在读/写之前指定创建的文件位置。还要确保该文件存在。否则它会抛出文件未找到异常。为此，试试这个，

File file = new File(Environment.getExternalStorageDirectory() + File.separator + "test.txt");
file.createNewFile();
if(file.exists())
{      
    OutputStream outputStream1 = new FileOutputStream(file);     
    String id="dfg";
    outputStream1.write(id.getBytes());
    outputStream1.close();
}