部落格摘要：很簡單，就是獲取裝置的唯一ID，直接上正文。

先來看看幾種比較單一的方式：

 IMEI

方式：TelephonyManager.getDeviceId():

問題

範圍：只能支援擁有通話功能的裝置，對於平板不可以。

永續性：返廠，資料擦除的時候不徹底，保留了原來的標識。

許可權：需要許可權：android.permission.READ_PHONE_STATE

bug: 有些廠家的實現有bug，返回一些不可用的資料

 Mac地址

ACCESS_WIFI_STATE許可權

有些裝置沒有WiFi，或者藍芽，就不可以，如果WiFi沒有開啟，硬體也不會返回Mac地址，不建議使用

ANDROID_ID

2.2（Froyo，8）版本系統會不可信，來自主要生產廠商的主流手機，至少有一個普遍發現的bug，這些有問題的手機相同的ANDROID_ID: 9774d56d682e549c

但是如果返廠的手機，或者被root的手機，可能會變

 
 Serial Number

從Android 2.3 (“Gingerbread”)開始可用，可以通過android.os.Build.SERIAL獲取，對於沒有通話功能的裝置，它會

返回一個唯一的device ID，

以下幾個是stackoverflow上評論較多的幾個，沒貼完，還有其他，綜合的，用到以上的部分方式：

有興趣的朋友可以再仔細看看

支援率比較高的（支援票數157）：androidID --> 剔除2.2版本（API 8）中有問題的手機，使用UUID替代 

import android.content.Context;
import android.content.SharedPreferences;
import android.provider.Settings.Secure;
import android.telephony.TelephonyManager;

import java.io.UnsupportedEncodingException;
import java.util.UUID;

public class DeviceUuidFactory {

    protected static final String PREFS_FILE = "device_id.xml";
    protected static final String PREFS_DEVICE_ID = "device_id";
    protected static volatile UUID uuid;

    public DeviceUuidFactory(Context context) {
        if (uuid == null) {
            synchronized (DeviceUuidFactory.class) {
                if (uuid == null) {
                    final SharedPreferences prefs = context
                            .getSharedPreferences(PREFS_FILE, 0);
                    final String id = prefs.getString(PREFS_DEVICE_ID, null);
                    if (id != null) {
                        // Use the ids previously computed and stored in the
                        // prefs file
                        uuid = UUID.fromString(id);
                    } else {
                        final String androidId = Secure.getString(
                            context.getContentResolver(), Secure.ANDROID_ID);
                        // Use the Android ID unless it's broken, in which case
                        // fallback on deviceId,
                        // unless it's not available, then fallback on a random
                        // number which we store to a prefs file
                        try {
                            if (!"9774d56d682e549c".equals(androidId)) {
                                uuid = UUID.nameUUIDFromBytes(androidId
                                        .getBytes("utf8"));
                            } else {
                                final String deviceId = ((TelephonyManager) 
                                        context.getSystemService(
                                            Context.TELEPHONY_SERVICE)
                                            .getDeviceId();
                                uuid = deviceId != null ? UUID
                                        .nameUUIDFromBytes(deviceId
                                                .getBytes("utf8")) : UUID
                                        .randomUUID();
                            }
                        } catch (UnsupportedEncodingException e) {
                            throw new RuntimeException(e);
                        }
                        // Write the value out to the prefs file
                        prefs.edit()
                                .putString(PREFS_DEVICE_ID, uuid.toString())
                                .commit();
                    }
                }
            }
        }
    }

    /**
     * Returns a unique UUID for the current android device. As with all UUIDs,
     * this unique ID is "very highly likely" to be unique across all Android
     * devices. Much more so than ANDROID_ID is.
     * 
     * The UUID is generated by using ANDROID_ID as the base key if appropriate,
     * falling back on TelephonyManager.getDeviceID() if ANDROID_ID is known to
     * be incorrect, and finally falling back on a random UUID that's persisted
     * to SharedPreferences if getDeviceID() does not return a usable value.
     * 
     * In some rare circumstances, this ID may change. In particular, if the
     * device is factory reset a new device ID may be generated. In addition, if
     * a user upgrades their phone from certain buggy implementations of Android
     * 2.2 to a newer, non-buggy version of Android, the device ID may change.
     * Or, if a user uninstalls your app on a device that has neither a proper
     * Android ID nor a Device ID, this ID may change on reinstallation.
     * 
     * Note that if the code falls back on using TelephonyManager.getDeviceId(),
     * the resulting ID will NOT change after a factory reset. Something to be
     * aware of.
     * 
     * Works around a bug in Android 2.2 for many devices when using ANDROID_ID
     * directly.
     * 
     * @see http://code.google.com/p/android/issues/detail?id=10603
     * 
     * @return a UUID that may be used to uniquely identify your device for most
     *         purposes.
     */
    public UUID getDeviceUuid() {
        return uuid;
    }
}
 

根據版本進行判斷的方式：Serial序列號-->UUID （支援數31）

通過Serial 即可，在覆蓋率上，你已經成功的獲得了98.4%的使用者，剩下的1.6%的使用者系統是在9 以下的。

通過AndroidID獲取，前面已經說過，在8上，有些商家的手機會有一些bug，返回相同的AndroidID，如果Serial和AndroidID都不行

/**
 * Return pseudo unique ID
 * @return ID
 */
public static String getUniquePsuedoID()
{
    // If all else fails, if the user does have lower than API 9 (lower
    // than Gingerbread), has reset their phone or 'Secure.ANDROID_ID'
    // returns 'null', then simply the ID returned will be solely based
    // off their Android device information. This is where the collisions
    // can happen.
    // Thanks http://www.pocketmagic.net/?p=1662!
    // Try not to use DISPLAY, HOST or ID - these items could change.
    // If there are collisions, there will be overlapping data
    String m_szDevIDShort = "35" + (Build.BOARD.length() % 10) + (Build.BRAND.length() % 10) + (Build.CPU_ABI.length() % 10) + (Build.DEVICE.length() % 10) + (Build.MANUFACTURER.length() % 10) + (Build.MODEL.length() % 10) + (Build.PRODUCT.length() % 10);

    // Thanks to @Roman SL!
    // http://stackoverflow.com/a/4789483/950427
    // Only devices with API >= 9 have android.os.Build.SERIAL
    // http://developer.android.com/reference/android/os/Build.html#SERIAL
    // If a user upgrades software or roots their phone, there will be a duplicate entry
    String serial = null;
    try
    {
        serial = android.os.Build.class.getField("SERIAL").get(null).toString();

        // Go ahead and return the serial for api => 9
        return new UUID(m_szDevIDShort.hashCode(), serial.hashCode()).toString();
    }
    catch (Exception e)
    {
        // String needs to be initialized
        serial = "serial"; // some value
    }

    // Thanks @Joe!
    // http://stackoverflow.com/a/2853253/950427
    // Finally, combine the values we have found by using the UUID class to create a unique identifier
    return new UUID(m_szDevIDShort.hashCode(), serial.hashCode()).toString();
}

不用READ_PHONE_STATE許可權直接獲取ROM資訊的方式：（支援率較低 16）

String m_szDevIDShort = "35" + //we make this look like a valid IMEI
            Build.BOARD.length()%10+ Build.BRAND.length()%10 +
            Build.CPU_ABI.length()%10 + Build.DEVICE.length()%10 +
            Build.DISPLAY.length()%10 + Build.HOST.length()%10 +
            Build.ID.length()%10 + Build.MANUFACTURER.length()%10 +
            Build.MODEL.length()%10 + Build.PRODUCT.length()%10 +
            Build.TAGS.length()%10 + Build.TYPE.length()%10 +
            Build.USER.length()%10 ; //13 digits

最後貼上自己在專案中用的：

public static String getDeviceId(Context context) {
		String deviceId = "";
		if (deviceId != null && !"".equals(deviceId)) {
return deviceId;
}
		if (deviceId == null || "".equals(deviceId)) {
			try {
				deviceId = getLocalMac(context).replace(":", "");
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		if (deviceId == null || "".equals(deviceId)) {
			try {
				deviceId = getAndroidId(context);
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		if (deviceId == null || "".equals(deviceId)) {
			
			if (deviceId == null || "".equals(deviceId)) {
				UUID uuid = UUID.randomUUID();
				deviceId = uuid.toString().replace("-", "");
				writeDeviceID(deviceId);
			}
		}
		return deviceId;
	}

// IMEI碼
	private static String getIMIEStatus(Context context) {
		TelephonyManager tm = (TelephonyManager) context
				.getSystemService(Context.TELEPHONY_SERVICE);
		String deviceId = tm.getDeviceId();
		return deviceId;
	}

	// Mac地址
	private static String getLocalMac(Context context) {
		WifiManager wifi = (WifiManager) context
				.getSystemService(Context.WIFI_SERVICE);
		WifiInfo info = wifi.getConnectionInfo();
		return info.getMacAddress();
	}

	// Android Id
	private static String getAndroidId(Context context) {
		String androidId = Settings.Secure.getString(
				context.getContentResolver(), Settings.Secure.ANDROID_ID);
		return androidId;
	}

	public static void saveDeviceID(String str) {
		try {
			FileOutputStream fos = new FileOutputStream(file);
			Writer out = new OutputStreamWriter(fos, "UTF-8");
			out.write(str);
			out.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public static String readDeviceID() {
		StringBuffer buffer = new StringBuffer();
		try {
			FileInputStream fis = new FileInputStream(file);
			InputStreamReader isr = new InputStreamReader(fis, "UTF-8");
			Reader in = new BufferedReader(isr);
			int i;
			while ((i = in.read()) > -1) {
				buffer.append((char) i);
			}
			in.close();
			return buffer.toString();
		} catch (IOException e) {
			e.printStackTrace();
			return null;
		}
	}