Java常用代码的实现

• 正则匹配
• 时间相关
• 更新中...

String contactInfo = "12345678909";


private static final Pattern sqlPattern = Pattern.compile("^1[3|4|5|7|8|9][0-9]{9}$");
Matcher matcher = sqlPattern.matcher(contactInfo);
if (matcher.find()) {
    return "匹配";
}


if (Pattern.matches("^1[3|4|5|7|8|9][0-9]{9}$", contactInfo)) {
    return PHONE;
}


boolean b = contactInfo.matches("^1[3|4|5|7|8|9][0-9]{9}$"）; 


// 匹配纯数字
String reg = "^(\d+)$";

// 匹配中文
String reg = "^[u4E00-u9FA5]$";

// sql防注入
String reg = "(?:')|(?:--)|(/\*(?:.|[\n\r])*?\*/)|"
        + "(\b(select|update|and|or|delete|insert|trancate|char|into|substr|ascii|declare|exec|count|master|into|drop|execute)\b)";
        
// 匹配邮箱
 String reg = "^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$";

 // 匹配手机号码
 String reg = "^1[3|4|5|7|8|9][0-9]{9}$";

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

// 定义日期格式
private static final DateTimeFormatter FMT = DateTimeFormatter.ofPattern("yyyyMMdd");

// 自定义格式的系统当前时间
String currentTime = FMT.format(LocalDateTime.now());
String currentTime = LocalDateTime.now().format(FMT);

int currentHour = LocalDateTime.now().getHour();
 

// 系统当前时间的前一天和后一天
String beforeTime = FMT.format(LocalDateTime.now().minusDays(1))
String afterTime = FMT.format(LocalDateTime.now().plusDays(1)

// 年月日时分秒对应的minus或plus前缀的获取时间API，都是相同格式，返回值均为LocalDateTime类型
minusYears()、
plusMinutes()...

// 获取当天零点
LocalDateTime localDateTime = LocalDateTime.of(LocalDate.now(), LocalTime.MIN)
// 转换为毫秒时间戳
Long localTimestamp = localDateTime.toEpochSecond(ZoneOffset.of("+8")) * 1000;
// 获取当前时间的整点
LocalDateTime localDateTime = LocalDateTime.of(localDateTime.getYear(), localDateTime.getMonthValue(), localDateTime.getDayOfMonth(), localDateTime.getHour(), 0, 0);


public String transferFormat(String date) {

    DateTimeFormatter oldFormat = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    LocalDateTime tempDate = LocalDateTime.parse(date, oldFormat);
    DateTimeFormatter newFormat = DateTimeFormatter.ofPattern("yyyyMMdd");
    String newDate = tempDate.format(newFormat);
    return newDate;
}