Commonly Used Utility Classes in Android Development

/**     * Supplement: Calculate the actual distance between two points     *     * @return meters     */    public static double getDistance(double longitude1, double latitude1, double longitude2, double latitude2) {        // Latitude        double lat1 = (Math.PI / 180) * latitude1;        double lat2 = (Math.PI / 180) * latitude2;        // Longitude        double lon1 = (Math.PI / 180) * longitude1;        double lon2 = (Math.PI / 180) * longitude2;        // Radius of the Earth        double R = 6371;        // Distance between the two points in km. To get meters, multiply the result by 1000.        double d = Math.acos(Math.sin(lat1) * Math.sin(lat2) + Math.cos(lat1) * Math.cos(lat2) * Math.cos(lon2 - lon1)) * R;        return d * 1000;    }

/**     * Check if the SD card is available     * @return returns true if the SD card is available     */    public static boolean hasSdcard() {        String status = Environment.getExternalStorageState();        return Environment.MEDIA_MOUNTED.equals(status);    }    /**     * Read the content of the file     * &lt;br&gt;     * Default utf-8 encoding     * @param filePath file path     * @return string     * @throws IOException     */    public static String readFile(String filePath) throws IOException {        return readFile(filePath, "utf-8");    }    /**     * Read the content of the file     * @param filePath file directory     * @param charsetName character encoding     * @return String string     */    public static String readFile(String filePath, String charsetName) throws IOException {        if (TextUtils.isEmpty(filePath))            return null;        if (TextUtils.isEmpty(charsetName))            charsetName = "utf-8";            File file = new File(filePath);            StringBuilder fileContent = new StringBuilder("");        if (file == null || !file.isFile())            return null;            BufferedReader reader = null;        try {                InputStreamReader is = new InputStreamReader(new FileInputStream(file), charsetName);                reader = new BufferedReader(is);                String line = null;            while ((line = reader.readLine()) != null) {                if (!fileContent.toString().equals("")) {                    fileContent.append("\n");                }                fileContent.append(line);            }            return fileContent.toString();        } finally {            if (reader != null) {                try {                    reader.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }    }    /**     * Read text file into a List of strings (default utf-8 encoding)     * @param filePath file directory     * @return returns null if the file does not exist, otherwise returns a string collection     * @throws IOException     */    public static List readFileToList(String filePath) throws IOException {        return readFileToList(filePath, "utf-8");    }    /**     * Read text file into a List of strings     * @param filePath file directory     * @param charsetName character encoding     * @return returns null if the file does not exist, otherwise returns a string collection     */    public static List readFileToList(String filePath, String charsetName) throws IOException {        if (TextUtils.isEmpty(filePath))            return null;        if (TextUtils.isEmpty(charsetName))            charsetName = "utf-8";        File file = new File(filePath);        List fileContent = new ArrayList<>();        if (file == null || !file.isFile()) {            return null;        }        BufferedReader reader = null;        try {            InputStreamReader is = new InputStreamReader(new FileInputStream(file), charsetName);            reader = new BufferedReader(is);            String line = null;            while ((line = reader.readLine()) != null) {                fileContent.add(line);            }            return fileContent;        } finally {            if (reader != null) {                try {                    reader.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }    }    /**     * Write data to a file     * @param filePath file directory     * @param content content to be written     * @param append if true, the data will be written to the end of the file instead of the beginning     * @return returns true if the write is successful, returns false if it fails     * @throws IOException     */    public static boolean writeFile(String filePath, String content, boolean append) throws IOException {        if (TextUtils.isEmpty(filePath))            return false;        if (TextUtils.isEmpty(content))            return false;        FileWriter fileWriter = null;        try {            createFile(filePath);            fileWriter = new FileWriter(filePath, append);            fileWriter.write(content);            fileWriter.flush();            return true;        } finally {            if (fileWriter != null) {                try {                    fileWriter.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }    }    /**     * Write data to a file&lt;br&gt;     * Default writes data to the beginning of the file     * @param filePath file directory     * @param stream byte input stream     * @return returns true if the write is successful, otherwise returns false     * @throws IOException     */    public static boolean writeFile(String filePath, InputStream stream) throws IOException {        return writeFile(filePath, stream, false);    }    /**     * Write data to a file     * @param filePath file directory     * @param stream byte input stream     * @param append if true, the data will be written to the end of the file; if false, the original data will be cleared and written from the beginning     * @return returns true if the write is successful, otherwise returns false     * @throws IOException     */    public static boolean writeFile(String filePath, InputStream stream, boolean append) throws IOException {        if (TextUtils.isEmpty(filePath))            throw new NullPointerException("filePath is Empty");        if (stream == null)            throw new NullPointerException("InputStream is null");        return writeFile(new File(filePath), stream, append);    }    /**     * Write data to a file     * Default writes data to the beginning of the file     * @param file specified file     * @param stream byte input stream     * @return returns true if the write is successful, otherwise returns false     * @throws IOException     */    public static boolean writeFile(File file, InputStream stream) throws IOException {        return writeFile(file, stream, false);    }    /**     * Write data to a file     * @param file specified file     * @param stream byte input stream     * @param append if true, data will be written to the beginning; if false, the original data will be cleared and written from the beginning     * @return returns true if the write is successful, otherwise returns false     * @throws IOException     */    public static boolean writeFile(File file, InputStream stream, boolean append) throws IOException {        if (file == null)            throw new NullPointerException("file = null");        OutputStream out = null;        try {            createFile(file.getAbsolutePath());            out = new FileOutputStream(file, append);            byte data[] = new byte[1024];            int length = -1;            while ((length = stream.read(data)) != -1) {                out.write(data, 0, length);            }            out.flush();            return true;        } finally {            if (out != null) {                try {                    out.close();                    stream.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }    }

/**     * Convert long time to yyyy-MM-dd HH:mm:ss string<br>     * @param timeInMillis time long value     * @return yyyy-MM-dd HH:mm:ss     */    public static String getDateTimeFromMillis(long timeInMillis) {        return getDateTimeFormat(new Date(timeInMillis));    }    /**     * Convert date to yyyy-MM-dd HH:mm:ss string     * <br>     * @param date Date object     * @return  yyyy-MM-dd HH:mm:ss     */    public static String getDateTimeFormat(Date date) {        return dateSimpleFormat(date, defaultDateTimeFormat.get());    }    /**     * Convert year, month, day int to yyyy-MM-dd string     * @param year year     * @param month month 1-12     * @param day day     * Note: month represents Calendar month, which is one less than actual     * No input item checks were made     */    public static String getDateFormat(int year, int month, int day) {        return getDateFormat(getDate(year, month, day));    }    /**     * Get HH:mm:ss time     * @param date     * @return     */    public static String getTimeFormat(Date date) {        return dateSimpleFormat(date, defaultTimeFormat.get());    }    /**     * Format date display format     * @param sdate original date format "yyyy-MM-dd"     * @param format formatted date format     * @return formatted date display     */    public static String dateFormat(String sdate, String format) {        SimpleDateFormat formatter = new SimpleDateFormat(format);        java.sql.Date date = java.sql.Date.valueOf(sdate);        return dateSimpleFormat(date, formatter);    }    /**     * Format date display format     * @param date Date object     * @param format formatted date format     * @return formatted date display     */    public static String dateFormat(Date date, String format) {        SimpleDateFormat formatter = new SimpleDateFormat(format);        return dateSimpleFormat(date, formatter);    }    /**     * Convert date to string     * @param date Date     * @param format SimpleDateFormat     * <br>     * Note: If SimpleDateFormat is null, use the default format yyyy-MM-dd HH:mm:ss     * @return yyyy-MM-dd HH:mm:ss     */    public static String dateSimpleFormat(Date date, SimpleDateFormat format) {        if (format == null)            format = defaultDateTimeFormat.get();        return (date == null ? "" : format.format(date));    }    /**     * Convert string in "yyyy-MM-dd HH:mm:ss" format to Date     * @param strDate time string     * @return Date     */    public static Date getDateByDateTimeFormat(String strDate) {        return getDateByFormat(strDate, defaultDateTimeFormat.get());    }    /**     * Convert string in "yyyy-MM-dd" format to Date     * @param strDate     * @return Date     */    public static Date getDateByDateFormat(String strDate) {        return getDateByFormat(strDate, defaultDateFormat.get());    }    /**     * Convert time string in specified format to Date object     * @param strDate time string     * @param format format string     * @return Date     */    public static Date getDateByFormat(String strDate, String format) {        return getDateByFormat(strDate, new SimpleDateFormat(format));    }    /**     * Convert String string to Date according to a certain format<br>     * Note: If SimpleDateFormat is null, use the default format yyyy-MM-dd HH:mm:ss     * @param strDate time string     * @param format SimpleDateFormat object     * @exception ParseException date format conversion error     */    private static Date getDateByFormat(String strDate, SimpleDateFormat format) {        if (format == null)            format = defaultDateTimeFormat.get();        try {            return format.parse(strDate);        } catch (ParseException e) {            e.printStackTrace();        }        return null;    }    /**     * Convert year, month int to date     * @param year year     * @param month month 1-12     * @param day day     * Note: month represents Calendar month, which is one less than actual     */    public static Date getDate(int year, int month, int day) {        Calendar mCalendar = Calendar.getInstance();        mCalendar.set(year, month - 1, day);        return mCalendar.getTime();    }    /**     * Calculate the number of days between two dates     *     * @param strat start date, format yyyy-MM-dd     * @param end end date, format yyyy-MM-dd     * @return number of days between the two dates     */    public static long getIntervalDays(String strat, String end) {        return ((java.sql.Date.valueOf(end)).getTime() - (java.sql.Date.valueOf(strat)).getTime()) / (3600 * 24 * 1000);    }    /**     * Get the current year     * @return year(int)     */    public static int getCurrentYear() {        Calendar mCalendar = Calendar.getInstance();        return mCalendar.get(Calendar.YEAR);    }    /**     * Get the current month     * @return month(int) 1-12     */    public static int getCurrentMonth() {        Calendar mCalendar = Calendar.getInstance();        return mCalendar.get(Calendar.MONTH) + 1;    }    /**     * Get the current day of the month     * @return day(int)     */    public static int getDayOfMonth() {        Calendar mCalendar = Calendar.getInstance();        return mCalendar.get(Calendar.DAY_OF_MONTH);    }    /**     * Get today's date (format: yyyy-MM-dd)     * @return yyyy-MM-dd     */    public static String getToday() {        Calendar mCalendar = Calendar.getInstance();        return getDateFormat(mCalendar.getTime());    }    /**     * Get yesterday's date (format: yyyy-MM-dd)     * @return yyyy-MM-dd     */    public static String getYesterday() {        Calendar mCalendar = Calendar.getInstance();        mCalendar.add(Calendar.DATE, -1);        return getDateFormat(mCalendar.getTime());    }    /**     * Get the day before yesterday's date (format: yyyy-MM-dd)     * @return yyyy-MM-dd     */    public static String getBeforeYesterday() {        Calendar mCalendar = Calendar.getInstance();        mCalendar.add(Calendar.DATE, -2);        return getDateFormat(mCalendar.getTime());    }    /**     * Get the date a few days before or after     * @param diff difference: positive for pushing forward, negative for pushing back     * @return     */    public static String getOtherDay(int diff) {        Calendar mCalendar = Calendar.getInstance();        mCalendar.add(Calendar.DATE, diff);        return getDateFormat(mCalendar.getTime());    }    /**     * Get the date object after adding a certain number of days to a given date.     *     * @param //date given date object     * @param amount number of days to add; use a negative number for days before.     * @return Date object after adding a certain number of days.     */    public static String getCalcDateFormat(String sDate, int amount) {        Date date = getCalcDate(getDateByDateFormat(sDate), amount);        return getDateFormat(date);    }    /**     * Get the date object after adding a certain number of days to a given date.     *     * @param date given date object     * @param amount number of days to add; use a negative number for days before.     * @return Date object after adding a certain number of days.     */    public static Date getCalcDate(Date date, int amount) {        Calendar cal = Calendar.getInstance();        cal.setTime(date);        cal.add(Calendar.DATE, amount);        return cal.getTime();    }