java 如果目录中存在文件，我如何覆盖它
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how can i overwrite a file if it exists in directory
提问by remy boys
i'm saving image in my directory with same name (for a purpose) but when file is already exists there it won't get overwritten , how do i know that ? because when i'm saving this file the already existing file is not changing but when i use a different name for my file it works. so what i want is to replace the existing file with a new one. so far this is what i'm trying :
我正在以相同的名称（出于某种目的）将图像保存在我的目录中，但是当文件已经存在时，它不会被覆盖，我怎么知道？因为当我保存这个文件时，已经存在的文件没有改变，但是当我为我的文件使用不同的名称时，它可以工作。所以我想要的是用新文件替换现有文件。到目前为止，这就是我正在尝试的：
content.setDrawingCacheEnabled(true);
Bitmap bitmap = content.getDrawingCache(); // an bitmap file for saving
File file = new File(context.getApplicationContext().getFilesDir() + "/img.jpg"); //here's the path where i'm saving my file
if (file.exists()){
file.delete(); // here i'm checking if file exists and if yes then i'm deleting it but its not working
}
String path = file.getPath();
try {
file.createNewFile();
FileOutputStream ostream = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 60, ostream);
savedFile = new File(path);
ostream.close();
}
catch (Exception e)
{
e.printStackTrace();
}
i'm doing another check right after deleting existing file :
删除现有文件后，我正在做另一项检查：
if (file.exists()){
Toast.makeText(context , "Still EXISTS",Toast.LENGTH_SHORT).show();
}
and this time file is not here cause the toast is not appearing.
而这次文件不在这里，因为 toast 没有出现。
回答by sai
Add this line to Your Code
将此行添加到您的代码
FileWriter fw = new FileWriter(myDir + "/score.jpg", false);
回答by Jame
First, Let insert the permission in your AndroidManifest.xml file (less than Android 6.0 version)
首先，让我们在你的 AndroidManifest.xml 文件中插入权限（低于 Android 6.0 版本）
android:name="android.permission.WRITE_INTERNAL_STORAGE" />
Then, use the below code to write the bitmap to file
然后，使用下面的代码将位图写入文件
String path = Environment.getExternalStorageDirectory().toString();
OutputStream fOut = null;
File file = new File(path, "FitnessGirl"+".jpg"); // the File to save to
fOut = new FileOutputStream(file);
Bitmap pictureBitmap = content.getDrawingCache();// Your bitmap
//Bitmap pictureBitmap = getImageBitmap(myurl); // obtaining the Bitmap
pictureBitmap.compress(Bitmap.CompressFormat.JPEG, 85, fOut); // saving the Bitmap to a file compressed as a JPEG with 85% compression rate
fOut.flush();
fOut.close(); // do not forget to close the stream
MediaStore.Images.Media.insertImage(getContentResolver(),file.getAbsolutePath(),file.getName(),file.getName());
回答by Prokash Sarkar
Try this,
试试这个，
boolean result = Files.deleteIfExists(file.toPath());
Also make sure you have write permission enabled!
还要确保您已启用写入权限！
PS:From Android Lollipop you need the runtime permissionand the permission already set in manifest file won't work.
PS：在 Android Lollipop 中，您需要运行时权限，并且清单文件中已设置的权限将不起作用。
