MountInfo.java

package zce.app.sdpath;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;

import android.os.Environment;

/**
 * MountInfo dev = MountInfo.getInstance(); DevInfo info; info =
 * dev.getInternalInfo();// Internal SD Card Informations try { // Methods:
 * //获取内置sd卡路径 info.getLabel(); // SD 卡的名称 info.getMount_point();// SD 卡挂载点
 * info.getPath(); // SD 卡路径 info.getSysfs_path(); // ....没弄清楚什么意思 "\n\n"); }
 * catch (Exception e) { } info = dev.getExternalInfo();// External SD Card
 * Informations try { // Methods: //"获取外置sd卡路径 info.getLabel(); // SD 卡的名称
 * info.getMount_point();// SD 卡挂载点 info.getPath(); // SD 卡路径
 * info.getSysfs_path(); // ....没弄清楚什么意思 "\n\n"); } catch (Exception e) { }
 * 
 * @author zce
 * 
 */

public class MountInfo implements IDev {
	/**
	 * ***
	 */
	public final String HEAD = "dev_mount";
	public final String LABEL = "<label>";
	public final String MOUNT_POINT = "<mount_point>";
	public final String PATH = "<part>";
	public final String SYSFS_PATH = "<sysfs_path1...>";

	/**
	 * Label for the volume
	 */
	private final int NLABEL = 1;
	/**
	 * Partition
	 */
	private final int NPATH = 2;
	/**
	 * Where the volume will be mounted
	 */
	private final int NMOUNT_POINT = 3;
	private final int NSYSFS_PATH = 4;

	private final int DEV_INTERNAL = 0;
	private final int DEV_EXTERNAL = 1;

	private ArrayList<String> cache = new ArrayList<String>();

	private static MountInfo dev;
	private DevInfo info;

	private final File VOLD_FSTAB = new File(Environment.getRootDirectory()
			.getAbsoluteFile()
			+ File.separator
			+ "etc"
			+ File.separator
			+ "vold.fstab");

	public static MountInfo getInstance() {
		if (null == dev)
			dev = new MountInfo();
		return dev;
	}

	private DevInfo getInfo(final int device) {
		// for(String str:cache)
		// System.out.println(str);

		if (null == info)
			info = new DevInfo();

		try {
			initVoldFstabToCache();
		} catch (IOException e) {
			e.printStackTrace();
		}

		if (device >= cache.size())
			return null;
		String[] sinfo = cache.get(device).split(" ");

		info.setLabel(sinfo[NLABEL]);
		info.setMount_point(sinfo[NMOUNT_POINT]);
		info.setPath(sinfo[NPATH]);
		info.setSysfs_path(sinfo[NSYSFS_PATH]);

		return info;
	}

	/**
	 * init the words into the cache array
	 * 
	 * @throws IOException
	 */
	private void initVoldFstabToCache() throws IOException {
		cache.clear();
		BufferedReader br = new BufferedReader(new FileReader(VOLD_FSTAB));
		String tmp = null;
		while ((tmp = br.readLine()) != null) {
			// the words startsWith "dev_mount" are the SD info
			if (tmp.startsWith(HEAD)) {
				cache.add(tmp);
			}
		}
		br.close();
		cache.trimToSize();
	}

	@Override
	public DevInfo getInternalInfo() {
		return getInfo(DEV_INTERNAL);
	}

	@Override
	public DevInfo getExternalInfo() {
		return getInfo(DEV_EXTERNAL);
	}
}

interface IDev {
	DevInfo getInternalInfo();

	DevInfo getExternalInfo();
}