非常实用的Java工具类，拿走不谢（一）-原创手记-慕课网

一、时间工具类：格式化时间、计算时间
（1）DateUtils.java

package com.lhf;

import java.text.SimpleDateFormat;

/**
 * 日期格式化
 *
 * @description 
 *
 * @author lhf
 * @createDate 2017年9月4日
 */
public class DateUtils {

    public static String getCurrentDate(String aFormat) {
        String tDate = new SimpleDateFormat(aFormat).format(new java.util.Date(System.currentTimeMillis()));
        return tDate;
    }

    public static String getCurrentDate() {
        return DateUtils.getCurrentDate("yyyyMMdd");
    }
    public static String getCurrentTime() {
        return DateUtils.getCurrentDate("HHmmss");
    }
    public static String getCurrentDateAndTime() {
        return DateUtils.getCurrentDate("yyyyMMddHHmmss");
    }
    public static String getCurrentDateAndTimeFormat() {
        return DateUtils.getCurrentDate("yyyy-MM-dd HH:mm:ss");
    }

    public static String getNewRandomCode(int codeLen) {
        //首先定义随机数据源
        //根据需要得到的数据码的长度返回随机字符串
        java.util.Random randomCode = new java.util.Random();
        String strCode = "";
        while (codeLen &gt; 0) {
            int charCode=randomCode.nextInt(9);
            strCode += charCode;
            codeLen--;
        }
        return strCode;
    }

    public static void main(String[] args) {
        System.out.println(getNewRandomCode(20));
        System.out.println(getCurrentDate());
        System.out.println(getCurrentTime());
        System.out.println(getCurrentDateAndTime());
        System.out.println(getCurrentDateAndTimeFormat());
    }
}

（2）DateUtil.java

package com.utils;

import java.security.InvalidParameterException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

import com.shove.Convert;

/**
 * 时间工具类
 *
 * @description 
 *
 * @author lhf
 * @createDate 2018年6月25日
 */
public class DateUtil {

    /** 1秒对应的毫秒数 */
    public static final long MILLIS_IN_A_SECOND = 1000;

    /** 1分对应的秒数 */
    public static final long SECONDS_IN_A_MINUTE = 60;

    /** 1小时对应的分钟数 */
    public static final long MINUTES_IN_AN_HOUR = 60;

    /** 1天对应的小时数 */
    public static final long HOURS_IN_A_DAY = 24;

    /** 1星期对应的天数 */
    public static final int DAYS_IN_A_WEEK = 7;

    /** 1年对应的月数 */
    public static final int MONTHS_IN_A_YEAR = 12;

    /** 1天对应的毫秒数  */
    public static final long millSecondsInOneDay = HOURS_IN_A_DAY * MINUTES_IN_AN_HOUR * SECONDS_IN_A_MINUTE * MILLIS_IN_A_SECOND;

    /** 1分钟对应的毫秒数  */
    public static final long millSecondsInOneMinute = SECONDS_IN_A_MINUTE * MILLIS_IN_A_SECOND;

    /** 时间格式化*/
    public static final String DATE_FORMAT = "yyyyMMddHHmmssSSS";

    /**
     * 获取简单的日期
     * @return
     */
    public static String getSimpleDate() {
        SimpleDateFormat time = new SimpleDateFormat(DATE_FORMAT);
        String now = time.format(new Date());

        return now;
    }

    /**
     * 日期格式化
     *
     * @param date 日期
     * @param formate 格式，以本类定义的格式为准，可自行添加。
     * @return
     */
    public static String dateToString(Date date, String formate) {
        if (date == null) {
            return "";
        }

        return new SimpleDateFormat(formate).format(date);
    }

    /**
     * 字符串转日期 
     *
     * @param dateString 
     * @param format 日期格式
     * @return
     */
    public static Date strToDate(String dateString, String format){
        if(dateString == null) {
            throw new InvalidParameterException("dateString cannot be null!");
        }
        try {
            return new SimpleDateFormat(format).parse(dateString);
        } catch (ParseException e) {
            throw new RuntimeException("parse error! [dateString:"+ dateString +";format:"+ format +"]");
        }
    }

     /**
     * 计算两个日期之间相差的周年数，忽略时间
     * 
     * @param startDate
     * @param endDate
     * @return
     */
    public static int getYearsBetween(Date startDate, Date endDate) {
        if (startDate == null || endDate == null) {
            throw new InvalidParameterException("startDate and endDate cannot be null!");
        }
        if (startDate.after(endDate)) {
            throw new InvalidParameterException("startDate cannot be after endDate!");
        }

        Calendar calendar = Calendar.getInstance();
        calendar.setTime(startDate);
        int year1 = calendar.get(Calendar.YEAR);
        int month1 = calendar.get(Calendar.MONTH);
        int day1 = calendar.get(Calendar.DATE);

        calendar.setTime(endDate);
        int year2 = calendar.get(Calendar.YEAR);
        int month2 = calendar.get(Calendar.MONTH);
        int day2 = calendar.get(Calendar.DATE);

        int result = year2 - year1;
        if (month2 &lt; month1) {
            result--;
        } else if (month2 == month1 &amp;&amp; day2 &lt; day1) {
            result--;
        }
        return result;
    }

    /**
     * 根据生日获取年龄
     *
     * @param birthday
     * @return
     * @description 
     */
    public static int getAge(Date birthday) {
        return getYearsBetween(birthday, new Date()) + 1;
    }

    /**
     * 计算两个时间之间相差的天数,满一天算一天
     *
     * @param startDate
     * @param endDate
     * @return
     * @description 
     */
    public static int getDaysDiffFloor(Date startDate,Date endDate){
        if (startDate == null || endDate == null) {
            throw new InvalidParameterException("startDate and endDate cannot be null!");
        }
        if (startDate.after(endDate)) {
                throw new InvalidParameterException("startDate cannot be after endDate!");
        }
        double days = Math.floor((endDate.getTime() - startDate.getTime()) / (double)millSecondsInOneDay);  //满一天算一天
        return Convert.strToInt(String.format("%.0f", days), 0);
    }

    /**
     * 计算两个时间之间相差的天数，不满一天按一天算
     *
     * @param startDate
     * @param endDate
     * @return
     * @description 
     */
    public static int getDaysDiffCeil(Date startDate,Date endDate){
        if (startDate == null || endDate == null) {
            throw new InvalidParameterException("startDate and endDate cannot be null!");
        }
        if (startDate.after(endDate)) {
                throw new InvalidParameterException("startDate cannot be after endDate!");
        }
        double days = Math.ceil((endDate.getTime() - startDate.getTime()) / (double)millSecondsInOneDay);  //不满一天按一天算
        return Convert.strToInt(String.format("%.0f", days), 0);
    }

    /**
     * 统计两个日期之间包含的天数,忽略时间
     *
     * @param startDate
     * @param endDate
     * @return
     * @description 
     */
    public static int getDaysBetween(Date startDate, Date endDate) {
        if (startDate == null || endDate == null) {
            throw new InvalidParameterException("startDate and endDate cannot be null!");
        }
        Date _startDate = org.apache.commons.lang.time.DateUtils.truncate(startDate, Calendar.DATE);
        Date _endDate = org.apache.commons.lang.time.DateUtils.truncate(endDate,Calendar.DATE);
        if (_startDate.after(_endDate)) {
            throw new InvalidParameterException("startDate cannot be after endDate!");
        }
        return (int) ((_endDate.getTime() - _startDate.getTime()) / millSecondsInOneDay);
    }

    /**
     * 计算两个时间之间相差的分钟数,满一分钟算一分钟
     *
     * @param startDate
     * @param endDate
     * @return
     * @description 
     */
    public static long getMinutesDiffFloor(Date startDate,Date endDate){
        if (startDate == null || endDate == null) {
            throw new InvalidParameterException("startDate and endDate cannot be null!");
        }
        if (startDate.after(endDate)) {
                throw new InvalidParameterException("startDate cannot be after endDate!");
        }
        double days = Math.floor((endDate.getTime() - startDate.getTime()) / (double)millSecondsInOneMinute);  
        return Convert.strToLong(String.format("%.0f", days), 0);
    }

    /**
     * 日期增加
     *
     * @param date 日期
     * @param calendarType 增加类型，如：Calendar.YEAR，Calendar.DAY_OF_YEAR，Calendar.MONTH
     * @param value
     * @return
     */
    public static Date addDate(Date date,int calendarType,int calendarValue){
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.add(calendarType, calendarValue);
        return calendar.getTime();
    }

    /**
     * 日期增加n年
     *
     * @param date 日期
     * @param year 年数
     * @return
     */
    public static Date addYear(Date date,int year) {
        return addDate(date,Calendar.YEAR, year);
    }

    /**
     * 日期增加n月
     *
     * @param date 日期
     * @param month 月数
     * @return
     *
     * @author huangyunsong
     * @createDate 2015年12月21日
     */
    public static Date addMonth(Date date,int month) { 
        return addDate(date,Calendar.MONTH, month);
    }

    /**
     * 日期增加n天
     *
     * @param date 日期
     * @param day 天数
     * @return
     */
    public static Date addDay(Date date,int day) {
        return addDate(date,Calendar.DAY_OF_YEAR, day);
    }

    /**
     * 日期减少n年
     *
     * @param date 日期
     * @param year 年数
     * @return
     */
    public static Date minusYear(Date date,int year) {
        return addDate(date,Calendar.YEAR, -year);
    }

    /**
     * 日期减少n月
     *
     * @param date 日期
     * @param month 月数
     * @return
     */
    public static Date minusMonth(Date date,int month) { 
        return addDate(date,Calendar.MONTH, -month);
    }

    /**
     * 日期减少n天
     *
     * @param date 日期
     * @param day 天数
     * @return
     */
    public static Date minusDay(Date date,int day) {
        return addDate(date,Calendar.DAY_OF_YEAR, -day);
    }

    /**
     * 获取年
     * @param time
     * @return
     */
    public static int getYear(Date time) {
        if (time == null) {
            throw new InvalidParameterException("time cannot be null!");
        }
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(time);
        return calendar.get(Calendar.YEAR);
    }

    /**
     * 获取当前时间年
     * @return
     */
    public static int getCurrentYear() {
        return getYear(new Date());
    }

    /**
     * 获取月
     * @param time
     * @return
     */
    public static int getMonth(Date time) {
        if (time == null) {
            throw new InvalidParameterException("time cannot be null!");
        }
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(time);
        return calendar.get(Calendar.MONTH) + 1;
    }

    /**
     * 获取当前时间月
     * @return
     */
    public static int getCurrentMonth() {
        return getMonth(new Date());
    }

    /**
     * 获取日
     * @param time
     * @return
     */
    public static int getDay(Date time) {
        if (time == null) {
            throw new InvalidParameterException("time cannot be null!");
        }
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(time);
        return calendar.get(Calendar.DAY_OF_MONTH);
    }

    /**
     * 获取当前时间日
     * @return
     */
    public static int getCurrentDay() {
        return getDay(new Date());
    }

    /**
     * 判断date1是否在date2之后，忽略时间部分
     * 
     * @param date1
     * @param date2
     * @return
     */
    public static boolean isDateAfter(Date date1, Date date2) {
        Date theDate1 = org.apache.commons.lang.time.DateUtils.truncate(date1,Calendar.DATE);
        Date theDate2 = org.apache.commons.lang.time.DateUtils.truncate(date2,Calendar.DATE);
        return theDate1.after(theDate2);
    }

    /**
     * 判断date1是否在date2之前，忽略时间部分
     * 
     * @param date1
     * @param date2
     * @return
     */
    public static boolean isDateBefore(Date date1, Date date2) {
        return isDateAfter(date2, date1);
    }

    /**
     * 判断date1是否在date2之后       如:“2015-12-06 12：05：15”.after("2015-12-06 12:17:16") = true
     *
     * @author liudong
     * @createDate 2015年12月24日
     * @param val 
     * @param scale
     * @return
     */
    public static boolean isDatetimeAfter(Date date1, Date date2) {
        return date1.after(date2);
    }

    /**
     * 判断time1是否在time2之后，忽略日期部分
     * 
     * @param time1
     * @param time2
     * @return
     */
    public static boolean isTimeAfter(Date time1, Date time2) {
        Calendar calendar1 = Calendar.getInstance();
        calendar1.setTime(time1);
        calendar1.set(1900, 1, 1);
        Calendar calendar2 = Calendar.getInstance();
        calendar2.setTime(time2);
        calendar2.set(1900, 1, 1);
        return calendar1.after(calendar2);
    }

    /**
     * 判断time1是否在time2之前，忽略日期部分
     * 
     * @param time1
     * @param time2
     * @return
     */
    public static boolean isTimeBefore(Date time1, Date time2) {
        return isTimeAfter(time2, time1);
    }

    /**
     * 判断两个日期是否同一天（忽略时间部分）
     * 
     * @param date1
     * @param date2
     * @return
     */
    public static boolean isSameDay(Date date1, Date date2) {
        return org.apache.commons.lang.time.DateUtils.isSameDay(date1, date2);
    }

    /**
     * 判断是否过期
     *
     * @param validTime 生产日期
     * @param time 有效期 单位秒
     * @return
     */
    public static boolean isInValidTime(Date validTime, int time){
        long currTime = System.currentTimeMillis();
        long valid = validTime.getTime();

        return ((currTime - valid) &lt; time*1000);
    }

    /**
     * 获取时间的时间轴表示
     * @param date
     * @return
     */
    public static String getTimeLine(Date date){
        long now = new Date().getTime();
        long da1 = date.getTime();
        String timeline = "";
        if(now&gt;da1){//之前
            long a = now-da1;
            if(a/1000==0){
                timeline = "刚刚";
            }else {
                long a1 = a/1000;
                if(a1&lt;60){
                    timeline = a1+"秒前";
                } else{
                    long b = a1/60;
                    if(b&lt;60){
                        if(b&gt;30){
                            timeline = "半小时前";
                        }else{
                            timeline = b+"分钟前";
                        }
                    }else{
                        long c = b/60;
                        if(c&lt;24){
                            timeline = c+"小时前";
                        }else {
                            long d = c/24;
                            if(d&lt;30){
                                if(d&gt;7){
                                    timeline = (d/7)+"周前";
                                }else{
                                    timeline = d+"天前";
                                }
                            } else{
                                long e = d/30;
                                if(e&lt;12){
                                    timeline = e+"月前";
                                } else{
                                    timeline = dateToString(date, "yy/MM/dd");
                                }
                            }
                        }
                    }
                }
            }
        } else {
            long a = da1-now;
            if(a/1000==0){
                timeline = "刚刚";
            }else {

                long a1 = a/1000;{
                    if(a1&lt;60){
                        timeline = a1+"秒后";
                    } else{
                        long b = a1/60;

                        if(b&lt;60){
                            if(b==30){
                                timeline = "半小时后";
                            }else{
                                timeline = b+"分钟后";
                            }
                        }else{
                            long c = b/60;
                            if(c&lt;24){
                                timeline = c+"小时后";
                            }else {
                                long d = c/24;
                                if(d&lt;30){
                                    if(d%7==0){
                                        timeline = (d/7)+"周后";
                                    }else{
                                        timeline = d+"天后";
                                    }
                                } else{
                                    long e = d/30;
                                    if(e&lt;12){
                                        timeline = e+"月后";
                                    } else{
                                        timeline = dateToString(date, "yy/MM/dd");
                                    }
                                }

                            }

                        }
                    }
                }

            }
        }
        return timeline;
    }

    /**
     *  获取当前月份的第一天
     *
     * @author liudong
     * @createDate 2015年12月24日
     * @param val 
     * @param scale
     * @return
     */
    public static String getMonthFirstDay() {     
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");  
        Calendar calendar = Calendar.getInstance();     
        calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMinimum(Calendar.DAY_OF_MONTH));     
        String s = sdf.format(calendar.getTime());
        StringBuffer str = new StringBuffer().append(s).append(" 00:00:00");

        return str.toString();     
    }

    /**
     * 获取当前月份的最后一天
     *
     * @author liudong
     * @createDate 2015年12月24日
     * @param val 
     * @param scale
     * @return
     */
    public static String getMonthLastDay() {     
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");  
        Calendar calendar = Calendar.getInstance();     
        calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));     
        String s = sdf.format(calendar.getTime());
        StringBuffer str = new StringBuffer().append(s).append(" 23:59:59");

        return str.toString();    
    }

    /**
     * 获取今天次日的时间
     * 比如现在时间是：2018-07-03 14:53:35
     * 次日是：2018-07-04 00:00:00
     * DateUtil.getTodayNextDay(DateUtil.addDay(new Date(), 1))
     * 
     * @return
     *
     * @author liuhefei
     * @createDate 2018年7月3日
     */
    public static String getTodayNextDay(Date date) {     
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");  
        Calendar calendar = Calendar.getInstance();        
        String s = sdf.format(date);
        StringBuffer str = new StringBuffer().append(s).append(" 00:00:00");

        return str.toString();     
    }

   /**
     * 得到当前时间距2013-11-01 00:00:00的小时数
     * @return
     */
    public static String getHours(){
        SimpleDateFormat simple = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Date date = null;
        try {
            date = simple.parse("2013-11-01 00:00:00");
        } catch (ParseException e) {
            e.printStackTrace();
        }
        long millisecond=System.currentTimeMillis()-date.getTime();
        long temp = 1000*60*60 ;
        long hours = millisecond/temp;

        return Long.toString(hours);
    }

    /**
     * 获得当前周- 周一的日期
     *
     * @return
     */
    public static String getCurrentMonday() {
        int mondayPlus = getMondayPlus();
        GregorianCalendar currentDate = new GregorianCalendar();
        currentDate.add(Calendar.DATE, mondayPlus);
        Date monday = currentDate.getTime();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd 00:00:00");
        String preMonday = sdf.format(monday);
        return preMonday;
    }

    public static int getMondayPlus() {
        Calendar cd = Calendar.getInstance();
        // 获得今天是一周的第几天，星期日是第一天，星期一是第二天......
        int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK);
        if (dayOfWeek == 1) {
            return -6;
        } else {
            return 2 - dayOfWeek;
        }
    }

    /**
     * 获得当前周- 周日的日期
     *
     * @return
     */
    public static String getPreviousSunday() {
        int mondayPlus = getMondayPlus();
        GregorianCalendar currentDate = new GregorianCalendar();
        currentDate.add(Calendar.DATE, mondayPlus + 6);
        Date monday = currentDate.getTime();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd 23:59:59");
        String preMonday = sdf.format(monday);
        return preMonday;
    }

    /**
     * 返回2个日期相差的天数
     * @param fDate
     * @param oDate
     * @return
     */
    public static int getIntervalDays(Date fDate, Date oDate) {

       if (null == fDate || null == oDate) {

           return -1;
       }

       long intervalMilli = oDate.getTime() - fDate.getTime();

       return (int) (intervalMilli / (24 * 60 * 60 * 1000));

    }

    /**
     * 判断date1是否与date2相等，忽略时间部分
     * 
     * @param date1
     * @param date2
     * @return
     */
     public static boolean isDateEqual(Date date1, Date date2) {
        Date theDate1 = org.apache.commons.lang.time.DateUtils.truncate(date1,Calendar.DATE);
        Date theDate2 = org.apache.commons.lang.time.DateUtils.truncate(date2,Calendar.DATE);

        return theDate1.equals(theDate2);
    }

     /**
     * 日期格式化
     * 
     * @param date 
     * @param format 
     * 
     * @return 
     */
    public static Date dateToDate(Date date, String format) {
        if (date == null) {
            throw new InvalidParameterException("date cannot be null!");
        }

        SimpleDateFormat simpleDateFormat = new SimpleDateFormat(format);

        Date newDate = null;
        String dateStr = DateUtil.dateToString(date, format);
        try {
            newDate = simpleDateFormat.parse(dateStr);
        } catch (ParseException e) {
            throw new RuntimeException("parse error! [dateString:" + dateStr + ";format:" + format + "]");
        }

        return newDate;
    }

    /*
    public static void main(String[] args) {
        Date date = new Date();
        Date date1 = new Date();
        Date birthday = strToDate("19940705", "yyyyMMdd");

        //获取简单的日期
        System.out.println(getSimpleDate() + "\n");
        //日期格式化
        System.out.println(dateToString(date, "yyyyMMddHH-mmssSSS"));
        //字符串转日期
        System.out.println(strToDate("20180705", "yyyyMMdd"));

        //根据生日获取年龄
        System.out.println("你的年龄："+getAge(birthday));
        //计算两个日期质检相差的天数
        System.out.println(getDaysDiffFloor(date, date1));
        System.out.println("------------------");
        //日期增加
        System.out.println(addDate(date, Calendar.YEAR, 5));  //当前时间加5年
        System.out.println(addDate(date, Calendar.MONTH, 5));  //当前时间加5个月
        System.out.println(addDate(date, Calendar.DAY_OF_MONTH, 5));  //当前时间加5年
        System.out.println("------------------");
        //获取当前时间的年月日
        System.out.println(getYear(date) + "-" + getMonth(date) + "-" + getDay(date));
        //判断date是否在date1之后，忽略时间部分
        System.out.println(isDateAfter(date, date1));

        //获取时间的时间轴
        System.out.println(getTimeLine(date));
        //获取当前月份的第一天
        System.out.println("本月的第一天：" + getMonthFirstDay());
        System.out.println("本月的最后一天：" + getMonthLastDay());
        //获取今天次日的时间
        System.out.println("今天次日的时间是："+getTodayNextDay(date));

        //得到当前时间距2013-11-01 00:00:00的小时数
        System.out.println(getHours());

        //获取本周周一和周日的日期
        System.out.println("本周周一的日期：" + getCurrentMonday());
        System.out.println("本周周日的日期：" + getPreviousSunday());
        //返回两个日期相差的天数
        System.out.println(getIntervalDays(date,date1));
        //判断两个日期是否相等，忽略时分秒
        System.out.println(isDateEqual(date,date1));
        //计算两个日期相差的周年数
        System.out.println(getYearsBetween(date,addDate(date, Calendar.YEAR, 5)));
    }*/

    public static void main(String[] args) {
        System.out.println(getTodayNextDay(new Date()));

        Calendar calendar = Calendar.getInstance();        
        System.out.println(calendar.getTime());

        System.out.println(addDay(new Date(), 1));

        Date date = addDay(new Date(), 1);
        System.out.println(getTodayNextDay(date));

        System.out.println("--------------");

        System.out.println(getTodayNextDay(addDay(new Date(), 1)));

        System.out.println(addMonth(new Date(), 1));

        System.out.println(getTodayNextDay(addDay(addMonth(new Date(), 1), 1)));
    }
}

二、统计一个项目工程的文件数、代码行数、注释行数、空白行数
CodeCounder.java

package com.lhf;

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

/**
 * 代码行数统计
 *
 * @description 
 *
 * @author lhf
 * @createDate 2018年6月12日
 */
public class CodeCounter {

    /**
     * 代码行数统计
     */
    public static void main(String[] args) {
        String file = CodeCounter.class.getResource("/").getFile();
        //String path = file.replace("target/test-classes", "src");
        //String path = file.replace("/JavaUtil/src/com/lhf/CodeCounter.java", "src");
        String path="D:/code/java1/JavaUtil/src";

        ArrayList al = getFile(new File(path));
        for (File f : al) {
            if (f.getName().matches(".*\\.java$")){ // 匹配java格式的文件
                count(f);
                System.out.println(f);
            }
        }
        System.out.println("统计文件：" + files);
        System.out.println("代码行数：" + codeLines);
        System.out.println("注释行数：" + commentLines);
        System.out.println("空白行数：" + blankLines);
    }

    static long files = 0;
    static long codeLines = 0;
    static long commentLines = 0;
    static long blankLines = 0;
    static ArrayList fileArray = new ArrayList();

    /**
     * 获得目录下的文件和子目录下的文件
     * @param f
     * @return
     */
    public static ArrayList getFile(File f) {
        File[] ff = f.listFiles();
        for (File child : ff) {
            if (child.isDirectory()) {
                getFile(child);
            } else
                fileArray.add(child);
        }
        return fileArray;

    }

    /**
     * 统计方法
     * @param f
     */
    private static void count(File f) {
        BufferedReader br = null;
        boolean flag = false;
        try {
            br = new BufferedReader(new FileReader(f));
            String line = "";
            while ((line = br.readLine()) != null) {
                line = line.trim(); // 除去注释前的空格
                if (line.matches("^[ ]*$")) { // 匹配空行
                    blankLines++;
                } else if (line.startsWith("//")) {
                    commentLines++;
                } else if (line.startsWith("/*") &amp;&amp; !line.endsWith("*/")) {
                    commentLines++;
                    flag = true;
                } else if (line.startsWith("/*") &amp;&amp; line.endsWith("*/")) {
                    commentLines++;
                } else if (flag == true) {
                    commentLines++;
                    if (line.endsWith("*/")) {
                        flag = false;
                    }
                } else {
                    codeLines++;
                }
            }
            files++;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                    br = null;
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

}

三、获取你电脑的Mac地址
MacUtils.java

package com.lhf;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/**
 * MAC地址工具
 *
 * @description 
 *
 * @author lhf
 * @createDate 2017年9月12日
 */
public class MacUtils {

    /**
     * 获取当前操作系统名称. return 操作系统名称 例如:windows,Linux,Unix等.
     */
    public static String getOSName() {
        return System.getProperty("os.name").toLowerCase();
    }

    /**
     * 获取Unix网卡的mac地址.
     * 
     * @return mac地址
     */
    public static String getUnixMACAddress() {
        String mac = null;
        BufferedReader bufferedReader = null;
        Process process = null;
        try {
            /**
             * Unix下的命令，一般取eth0作为本地主网卡 显示信息中包含有mac地址信息
             */
            process = Runtime.getRuntime().exec("ifconfig eth0");
            bufferedReader = new BufferedReader(new InputStreamReader(
                    process.getInputStream()));
            String line = null;
            int index = -1;
            while ((line = bufferedReader.readLine()) != null) {
                /**
                 * 寻找标示字符串[hwaddr]
                 */
                index = line.toLowerCase().indexOf("hwaddr");
                /**
                 * 找到了
                 */
                if (index != -1) {
                    /**
                     * 取出mac地址并去除2边空格
                     */
                    mac = line.substring(index + "hwaddr".length() + 1).trim();
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (bufferedReader != null) {
                    bufferedReader.close();
                }
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            bufferedReader = null;
            process = null;
        }

        return mac;
    }

    /**
     * 获取Linux网卡的mac地址.
     * 
     * @return mac地址
     */
    public static String getLinuxMACAddress() {
        String mac = null;
        BufferedReader bufferedReader = null;
        Process process = null;
        try {
            /**
             * linux下的命令，一般取eth0作为本地主网卡 显示信息中包含有mac地址信息
             */
            process = Runtime.getRuntime().exec("ifconfig eth0");
            bufferedReader = new BufferedReader(new InputStreamReader(
                    process.getInputStream()));
            String line = null;
            int index = -1;
            while ((line = bufferedReader.readLine()) != null) {
                index = line.toLowerCase().indexOf("硬件地址");
                /**
                 * 找到了
                 */
                if (index != -1) {
                    /**
                     * 取出mac地址并去除2边空格
                     */
                    mac = line.substring(index + 4).trim();
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (bufferedReader != null) {
                    bufferedReader.close();
                }
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            bufferedReader = null;
            process = null;
        }

        // 取不到，试下Unix取发
        if (mac == null){
            return getUnixMACAddress();
        }

        return mac;
    }

    /**
     * 获取widnows网卡的mac地址.
     * 
     * @return mac地址
     */
    public static String getWindowsMACAddress() {
        String mac = null;
        BufferedReader bufferedReader = null;
        Process process = null;
        try {
            /**
             * windows下的命令，显示信息中包含有mac地址信息
             */
            process = Runtime.getRuntime().exec("ipconfig /all");
            bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
            String line = null;
            int index = -1;
            while ((line = bufferedReader.readLine()) != null) {
                /**
                 * 寻找标示字符串[physical address]
                 */
//              index = line.toLowerCase().indexOf("physical address");
//              if (index != -1) {
                if (line.split("-").length == 6){
                    index = line.indexOf(":");
                    if (index != -1) {
                        /**
                         * 取出mac地址并去除2边空格
                         */
                        mac = line.substring(index + 1).trim();
                    }
                    break;
                }
                index = line.toLowerCase().indexOf("物理地址");
                if (index != -1) {
                    index = line.indexOf(":");
                    if (index != -1) {
                        /**
                         * 取出mac地址并去除2边空格
                         */
                        mac = line.substring(index + 1).trim();
                    }
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (bufferedReader != null) {
                    bufferedReader.close();
                }
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            bufferedReader = null;
            process = null;
        }

        return mac;
    }

    public static String getMac(){
        String os = getOSName();
        String mac;
        if (os.startsWith("windows")) {
            mac = getWindowsMACAddress();
        } else if (os.startsWith("linux")) {
            mac = getLinuxMACAddress();
        } else {
            mac = getUnixMACAddress();
        }
        return mac == null ? "" : mac;
    }

    /**
     * 测试用的main方法.
     * 
     * @param argc 运行参数.
     */
    public static void main(String[] argc) {
        String os = getOSName();
        System.out.println("os: " + os);
        if (os.startsWith("windows")) {
            String mac = getWindowsMACAddress();
            System.out.println("mac: " + mac);
        } else if (os.startsWith("linux")) {
            String mac = getLinuxMACAddress();
            System.out.println("mac: " + mac);
        } else {
            String mac = getUnixMACAddress();
            System.out.println("mac: " + mac);
        }
    }

}

由于篇幅问题，就分享到这里，后期还会不断更新，请诸君多多支持！如果对你有帮助，就给我点个赞吧！

非常实用的Java工具类，拿走不谢（一）原创