Andorid10无法获取IMEI，读写文件也被限制。

获取设备唯一ID逻辑。

如果Android10以上 -> 在设备的外部目录创建UUID，只要用户没有手动删除该文件UUID一直存在。

如果Android10以下，获取设备IMEI

如果没有获取到IMEI -> 在设备外部目录创建UUIID

如果考虑IMEI是私密信息，可以对IMEI做MD5再返回。

import android.annotation.SuppressLint;

import android.content.ContentResolver;

import android.content.ContentUris;

import android.content.ContentValues;

import android.content.Context;

import android.content.SharedPreferences;

import android.database.Cursor;

import android.net.Uri;

import android.os.Build;

import android.os.Environment;

import android.provider.MediaStore;

import android.telephony.TelephonyManager;

import android.text.TextUtils;

import android.util.Log;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.util.UUID;

/**

* create by Huanmie on 2019-11-26 11:51

*/

public final class DeviceIdUtils {

private static final String TAG = DeviceIdUtils.class.getSimpleName();

private static final String TEMP_DIR = "system_config";

private static final String TEMP_FILE_NAME = "system_file";

private static final String TEMP_FILE_NAME_MIME_TYPE = "application/octet-stream";

private static final String SP_NAME = "device_info";

private static final String SP_KEY_DEVICE_ID = "device_id";

public static String getDeviceId(Context context) {

SharedPreferences sharedPreferences = context.getSharedPreferences(SP_NAME, Context.MODE_PRIVATE);

String deviceId = sharedPreferences.getString(SP_KEY_DEVICE_ID, null);

if (!TextUtils.isEmpty(deviceId)) {

return deviceId;

}

deviceId = getIMEI(context);

if (TextUtils.isEmpty(deviceId)) {

deviceId = createUUID(context);

}

sharedPreferences.edit()

.putString(SP_KEY_DEVICE_ID, deviceId)

.apply();

return deviceId;

}

private static String createUUID(Context context) {

String uuid = UUID.randomUUID().toString().replace("-", "");

if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.Q) {

Uri externalContentUri = MediaStore.Downloads.EXTERNAL_CONTENT_URI;

ContentResolver contentResolver = context.getContentResolver();

String[] projection = new String[]{

MediaStore.Downloads._ID

};

String selection = MediaStore.Downloads.TITLE + "=?";

String[] args = new String[]{

TEMP_FILE_NAME

};

Cursor query = contentResolver.query(externalContentUri, projection, selection, args, null);

if (query != null && query.moveToFirst()) {

Uri uri = ContentUris.withAppendedId(externalContentUri, query.getLong(0));

query.close();

InputStream inputStream = null;

BufferedReader bufferedReader = null;

try {

inputStream = contentResolver.openInputStream(uri);

if (inputStream != null) {

bufferedReader = new BufferedReader(new InputStreamReader(inputStream));

uuid = bufferedReader.readLine();

}

} catch (IOException e) {

e.printStackTrace();

} finally {

if (bufferedReader != null) {

try {

bufferedReader.close();

} catch (IOException e) {

e.printStackTrace();

}

}

if (inputStream != null) {

try {

inputStream.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

} else {

ContentValues contentValues = new ContentValues();

contentValues.put(MediaStore.Downloads.TITLE, TEMP_FILE_NAME);

contentValues.put(MediaStore.Downloads.MIME_TYPE, TEMP_FILE_NAME_MIME_TYPE);

contentValues.put(MediaStore.Downloads.DISPLAY_NAME, TEMP_FILE_NAME);

contentValues.put(MediaStore.Downloads.RELATIVE_PATH, Environment.DIRECTORY_DOWNLOADS + File.separator + TEMP_DIR);

Uri insert = contentResolver.insert(externalContentUri, contentValues);

if (insert != null) {

OutputStream outputStream = null;

try {

outputStream = contentResolver.openOutputStream(insert);

if (outputStream == null) {

return uuid;

}

outputStream.write(uuid.getBytes());

} catch (IOException e) {

e.printStackTrace();

} finally {

if (outputStream != null) {

try {

outputStream.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

}

}

} else {

File externalDownloadsDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);

File applicationFileDir = new File(externalDownloadsDir, TEMP_DIR);

if (!applicationFileDir.exists()) {

if (!applicationFileDir.mkdirs()) {

Log.e(TAG, "文件夹创建失败: " + applicationFileDir.getPath());

}

}

File file = new File(applicationFileDir, TEMP_FILE_NAME);

if (!file.exists()) {

FileWriter fileWriter = null;

try {

if (file.createNewFile()) {

fileWriter = new FileWriter(file, false);

fileWriter.write(uuid);

} else {

Log.e(TAG, "文件创建失败：" + file.getPath());

}

} catch (IOException e) {

Log.e(TAG, "文件创建失败：" + file.getPath());

e.printStackTrace();

} finally {

if (fileWriter != null) {

try {

fileWriter.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

} else {

FileReader fileReader = null;

BufferedReader bufferedReader = null;

try {

fileReader = new FileReader(file);

bufferedReader = new BufferedReader(fileReader);

uuid = bufferedReader.readLine();

bufferedReader.close();

fileReader.close();

} catch (IOException e) {

e.printStackTrace();

} finally {

if (bufferedReader != null) {

try {

bufferedReader.close();

} catch (IOException e) {

e.printStackTrace();

}

}

if (fileReader != null) {

try {

fileReader.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

}

}

return uuid;

}

private static String getIMEI(Context context) {

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {

return null;

}

try {

TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);

if (telephonyManager == null) {

return null;

}

@SuppressLint({"MissingPermission", "HardwareIds"}) String imei = telephonyManager.getDeviceId();

return imei;

} catch (Exception e) {

return null;

}

}

}