Android uses the File class to obtain file-related information based on the file path

How does Android get file-related information through the file path, such as file name, file size, creation time, relative path of the file, absolute path of the file, etc.:

As shown in the figure:

Code:

 

public class MainActivity extends Activity {

	private String path = "/storage/emulated/0/Android/data/cn.wps.moffice_eng/mm.doc";
	private TextView mTextView;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate (savedInstanceState);
		setContentView(R.layout.activity_main);
		initView();
	}

	@SuppressLint("SimpleDateFormat")
	private void initView() {
		// TODO Auto-generated method stub
		mTextView = (TextView) findViewById(R.id.textview);
		File f = new File(path);
		if (f.exists()) {
			FileInputStream fis = null;
			try {
				fis = new FileInputStream(f);
				String time = new SimpleDateFormat("yyyy-MM-dd")
						.format(new Date(f.lastModified()));
				System.out.println("File creation time" + time);
				System.out.println("File size:" + ShowLongFileSzie(f.length()));// Calculate file size
																			// B,KB,MB,
				System.out.println("文件大小:" + fis.available() + "B");
				System.out.println("File name: " + f.getName());
				System.out.println("Does the file exist: " + f.exists());
				System.out.println("The relative path of the file: " + f.getPath());
				System.out.println("Absolute path of file: " + f.getAbsolutePath());
				System.out.println("File can be read: " + f.canRead());
				System.out.println("File can be written: " + f.canWrite());
				System.out.println("File parent path: " + f.getParent());
				System.out.println("File size: " + f.length() + "B");
				System.out.println("File last modified time: " + new Date(f.lastModified()));
				System.out.println("Is it a file type: " + f.isFile());
				System.out.println("Is it a folder type: " + f.isDirectory());
				mTextView.setText("File creation time:" + time + "\n" + "File size:"
						+ ShowLongFileSzie(f.length()) + "\n" + "File name:"
						+ f.getName() + "\n" + "Does the file exist:" + f.exists() + "\n"
						+ "The relative path of the file:" + f.getPath() + "\n" + "The absolute path of the file:"
						+ f.getAbsolutePath() + "\n" + "File can be written:" + f.canWrite()
						+ "\n" + "Is it a folder type:" + f.isDirectory());
			} catch (Exception e) {
				e.printStackTrace ();
			}
		}
	}

	/****
	 * Calculate file size
	 *
	 * @param length
	 * @return
	 */
	public String ShowLongFileSzie(Long length) {
		if (length >= 1048576) {
			return (length / 1048576) + "MB";
		} else if (length >= 1024) {
			return (length / 1024) + "KB";
		} else if (length < 1024) {
			return length + "B";
		} else {
			return "0KB";
		}
	}

}

Don't forget to add permissions in AndroidManifest.xml!

 

<!-- SD card permissions-->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

 

Source code click to download