java常用util工具类

时间

package com.lcdzzz.utils;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class TimeUtils {

    //获取当前年份
    public static int getCurrentYear() {
        return Calendar.getInstance().get(Calendar.YEAR);
    }

    //获取当前月份
    public static int getCurrentMonth() {
        return Calendar.getInstance().get(Calendar.MONTH) + 1;
    }

    //获取年月日
    public static String getYMD() {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        String dateNowStr = sdf.format(new Date());
        System.out.println("格式化后的日期：" + dateNowStr);
        return dateNowStr;
    }

    /*
     * 获取当月第一天的时间
     * */
    public static Date getFisrtDayOfMonth(int year, int month) {
        Calendar cal = Calendar.getInstance();
        //设置年份
        cal.set(Calendar.YEAR, year);
        //设置月份
        cal.set(Calendar.MONTH, month - 1);
        //获取某月最小天数
        int firstDay = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
        //设置日历中月份的最小天数
        cal.set(Calendar.DAY_OF_MONTH, firstDay);
        //格式化日期
//        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
//        String firstDayOfMonth = sdf.format(cal.getTime());
        return cal.getTime();
    }

    /*
     * 获取当月最后一天的时间
     * */
    public static Date getLastDayOfMonth(int year, int month) {
        Calendar cal = Calendar.getInstance();
        //设置年份
        cal.set(Calendar.YEAR, year);
        //设置月份
        cal.set(Calendar.MONTH, month - 1);
        //获取某月最大天数
        int lastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
        //设置日历中月份的最大天数
        cal.set(Calendar.DAY_OF_MONTH, lastDay);
        //格式化日期
//        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
//        String lastDayOfMonth = sdf.format(cal.getTime());
        return cal.getTime();
    }


    /*
     * date转string
     * */
    public static String dateToString(Date value) {
        Date sqlDate = new java.sql.Date(value.getTime());
        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        return formatter.format(sqlDate);
    }

}

---

ip工具类

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class IpUtils {

    /**
     * 获取客户端真实 IP 地址
     *
     * @param request HttpServletRequest 对象
     * @return 客户端 IP 地址
     */
    public static String getClientIp(HttpServletRequest request) {
        String ipAddress = request.getHeader("X-Forwarded-For");

        if (ipAddress == null || ipAddress.isEmpty() || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader("Proxy-Client-IP");
        }

        if (ipAddress == null || ipAddress.isEmpty() || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader("WL-Proxy-Client-IP");
        }

        if (ipAddress == null || ipAddress.isEmpty() || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getRemoteAddr();
        }

        // 多个代理服务器的情况，取第一个非unknown的IP地址
        String[] ipArray = ipAddress.split(",");
        for (String ip : ipArray) {
            if (!"unknown".equalsIgnoreCase(ip)) {
                ipAddress = ip.trim();
                break;
            }
        }

        return ipAddress;
    }

    /**
     * 判断是否为内部 IP 地址
     *
     * @param ipAddress IP 地址字符串
     * @return 是否为内部 IP 地址
     */
    public static boolean isInternalIp(String ipAddress) {
        if (ipAddress == null || ipAddress.isEmpty()) {
            return false;
        }

        try {
            InetAddress inetAddress = InetAddress.getByName(ipAddress);
            byte[] addressBytes = inetAddress.getAddress();

            // 10.0.0.0/8
            if (addressBytes[0] == 10) {
                return true;
            }

            // 172.16.0.0/12
            if (addressBytes[0] == 172 && (addressBytes[1] >= 16 && addressBytes[1] <= 31)) {
                return true;
            }

            // 192.168.0.0/16
            if (addressBytes[0] == 192 && addressBytes[1] == 168) {
                return true;
            }
        } catch (UnknownHostException e) {
            // 处理异常
        }

        return false;
    }

    /**
     * 验证 IP 地址格式是否正确
     *
     * @param ipAddress IP 地址字符串
     * @return 是否为有效的 IP 地址
     */
    public static boolean isValidIpAddress(String ipAddress) {
        try {
            InetAddress.getByName(ipAddress);
            return true;
        } catch (UnknownHostException e) {
            return false;
        }
    }

    // 可以添加更多的方法，例如获取本机 IP 地址、计算 IP 地址之间的距离等
}