android: determining a symbolic link

问题

I am scanning all directories starting from "/" to find some particular directories like "MYFOLDER". However, the folder is that I get double instances of the same folder. This occurs because one folder is located in "/mnt/sdcard/MYFOLDER" and the same folder has a symbolic link in "/sdcard/MYFOLDER"..

My Question is, "Is there any way to determine whether the folder is a symbolic link or not?". Please give me some suggestions..

回答1:

This is essentially how they do in Apache Commons (subject to their license):

public static boolean isSymlink(File file) throws IOException {
  File canon;
  if (file.getParent() == null) {
    canon = file;
  } else {
    File canonDir = file.getParentFile().getCanonicalFile();
    canon = new File(canonDir, file.getName());
  }
  return !canon.getCanonicalFile().equals(canon.getAbsoluteFile());
}

Edit thanks to @LarsH comment. The above code only checks whether the children file is a symlink.

In order to answer the OP question, it's even easier:

public static boolean containsSymlink(File file) {
  return !file.getCanonicalFile().equals(file.getAbsoluteFile());
}

来源：https://stackoverflow.com/questions/7281612/android-determining-a-symbolic-link

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android