如何在android中獲取文件所有權和權限

Question

使用ls我得到以下信息。如何從android中的文件對象獲得相同的結果。 Like如何使用File Object獲取u0_a23名稱字符串。

root@android:/ # ls /proc/ -l             
dr-xr-xr-x root  root    2013-07-01 12:19 1 
dr-xr-xr-x root  root    2013-07-01 12:19 10 
dr-xr-xr-x root  root    2013-07-01 12:31 1069 
dr-xr-xr-x root  root    2013-07-01 12:19 11 
dr-xr-xr-x root  root    2013-07-01 12:19 12 
dr-xr-xr-x root  root    2013-07-01 12:19 13 
dr-xr-xr-x root  root    2013-07-01 12:19 14 
dr-xr-xr-x root  root    2013-07-01 12:19 2 
dr-xr-xr-x root  root    2013-07-01 12:19 25 
dr-xr-xr-x root  root    2013-07-01 12:19 26 
dr-xr-xr-x root  root    2013-07-01 12:19 27 
dr-xr-xr-x root  root    2013-07-01 12:19 28 
dr-xr-xr-x root  root    2013-07-01 12:19 29 
dr-xr-xr-x root  root    2013-07-01 12:19 290 
dr-xr-xr-x root  root    2013-07-01 12:19 292 
dr-xr-xr-x system system   2013-07-01 12:19 294 
dr-xr-xr-x root  root    2013-07-01 12:19 3 
dr-xr-xr-x system system   2013-07-01 12:19 30 
dr-xr-xr-x root  root    2013-07-01 12:19 31 
dr-xr-xr-x root  root    2013-07-01 12:19 33 
dr-xr-xr-x root  root    2013-07-01 12:19 34 
dr-xr-xr-x radio radio    2013-07-01 12:19 35 
dr-xr-xr-x u0_a23 u0_a23   2013-07-01 12:20 357 

Answer 1

您可以創建一個Process對象並執行該命令。您可以將File對象的路徑附加爲參數。之後，您可以從InputStream中讀取結果。

如果您需要示例，請發表評論。

Answer 2

在Java 7中有Files#getOwner，否則正如vRallev所說的，唯一的方法是使用Process。

嘗試一個過程，看看有多快（在我的設備上，在調試模式下的Galaxy S2只需要40ms，而不是我猜）。

我試圖用文件信息實現一個小對象FileInfo。也許你會發現它很有用。我不確定它每次都會起作用（我假設唯一缺少的參數可能是大小和類似的東西），但它可能是一個開始。

public static void test() { 
    long start = System.currentTimeMillis(); 
    BufferedWriter out; 
    BufferedReader in; 
    String test = ""; 
    List<FileInfo> fileInfoList = new ArrayList<FileInfo>(); 
    try { 
     Process proc = Runtime.getRuntime().exec("ls -l"); 
     out = new BufferedWriter(new OutputStreamWriter(proc.getOutputStream())); 
     in = new BufferedReader(new InputStreamReader(proc.getInputStream())); 
     String line = ""; 
     while((line = in.readLine()) != null) { 
      fileInfoList.add(createFileInfo(line.split("\\s+"))); 
     } 
     proc.waitFor(); 
     in.close(); 
     out.close(); 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
    long execTime = System.currentTimeMillis() - start; 
    System.out.println(execTime); 
} 

private static FileInfo createFileInfo(String... args) { 
    FileInfo fi = null; 
    if(args.length == 6) { 
     fi = new FileInfo(args[0],args[1],args[2],args[3] +" "+ args[4],args[5]); 
    } else if(args.length == 7) { 
     fi = new FileInfo(args[0],args[1],args[2],args[3],args[4] +" "+ args[5],args[6]); 
    } 
    return fi; 
} 

private static class FileInfo { 
    private String permissions; 
    private String owner; 
    private String group; 
    private String size; 
    private String date; 
    private String fileName; 

    private FileInfo(String permissions, String owner, String group, String size, String date, String fileName) { 
     this.permissions = permissions; 
     this.owner = owner; 
     this.group = group; 
     this.size = size; 
     this.date = date; 
     this.fileName = fileName; 
    } 

    private FileInfo(String permissions, String owner, String group, String date, String fileName) { 
     this.permissions = permissions; 
     this.owner = owner; 
     this.group = group; 
     this.date = date; 
     this.fileName = fileName; 
    } 
}