开发中的小技术

1、List集合去重

package com.ahc.demo;

import org.junit.Test;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class List集合去重 {
    @Test
    public void List集合去重(){
        List<Integer> integerList = new ArrayList<>();
        integerList.add(1);  integerList.add(2);  integerList.add(3);  integerList.add(4);
        integerList.add(1);  integerList.add(2);  integerList.add(3);  integerList.add(4);
        System.out.println(integerList);
        //list去重
        List<Object> collect = integerList.stream().distinct().collect(Collectors.toList());
        System.out.println(collect);
    }
}

2、Long类型转换成double

package com.ahc.demo;

import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.Date;

public class Long类型转成double {

    public static void main(String[] args) {
        // long类型的  184238903  转换成  double类型的1.84
        Long increOld = 184238903L;
        String increOldStr = String.valueOf(increOld);
        BigDecimal decimal = new BigDecimal(increOldStr).divide(new BigDecimal("100000000"));
        double doubleValue = decimal.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
        System.out.println(doubleValue);


    }
}

3、定时任务

package com.ahc.task;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.List;
import java.util.Map;

@EnableScheduling
@Component
public class 定时任务 {
    //CllDataTask
    @Autowired
    //private ITfcPassMidService tfcPassMidService;

    @Scheduled(cron= "0 */10 * * * ?")  //每十分钟
    public void getCllData() {
        /*TfcPassMid tfcPassMid = new TfcPassMid();
        //获取当前时间
        DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd hh:mm:ss");
        LocalDateTime now = LocalDateTime.now();
        String nowTime = df.format(now);
        //当前时间前10分钟
        LocalDateTime localDateTime = LocalDateTime.now().minusMinutes(10);
        String time = df.format(localDateTime);
        String datasql =
                "select * from normal.tfc_pass_mid where gcsj <= '"+nowTime+"' and " +
                        " gcsj > '"+time+"'";
        List<Map<String, Object>> dataMap = clickHouseClient.selectData(datasql);
        System.out.println(dataMap);
            for (Map<String, Object> data : dataMap) {
                tfcPassMid.setGcxh(data.get("gcxh").toString());
                tfcPassMid.setKkbh(data.get("kkbh").toString());
                tfcPassMid.setFxlx(data.get("fxlx").toString());
                tfcPassMid.setHphm(data.get("hphm").toString());
                String capture = data.get("capture_date").toString();
                DateTimeFormatter df1 = DateTimeFormatter.ofPattern("yyyy-MM-dd");
                LocalDate capture_date = LocalDate.parse(capture, df1);
                tfcPassMid.setCaptureDate(capture_date);
                tfcPassMidMapper.insert(tfcPassMid);
            }*/
        }

}

4、分页查询

package com.ahc.demo;

public class 分页查询 {
    public static void main(String[] args) {
        /**
         * limit len,size
         * len:偏移量  从len后面一条开始展示
         * size：每页显示的行数
         *
         * len = (页数 - 1) * size
         */
        //controller
        /**
         * public R<IPage<PersonVO>> page(Person person, Query query) {
         *     IPage<PersonVO> pages = personService.selectPage(person, query);
         *     return R.data(pages);
         * }
         */
        //service
        /**
         * IPage<PersonVO> selectPage(Person person, Query query);
         */
        //serviceImpl
        /**
         * public IPage<PersonVO> selectPage(Person person, Query query) {
         *    Page<Person> page = new Page<Person>();
         *    if (query.getCurrent() == null ) {
         *       query.setCurrent(1);
         *    }
         *    if (query.getSize() == null) {
         *       query.setSize(10);
         *    }
         *    List<Person> list = personMapper.selectPersonPage((query.getCurrent() - 1) * query.getSize(), query.getSize(), person);
         *    page.setRecords(list);
         *    page.setTotal(personMapper.selectPersonCount(person));
         *    page.setPages(page.getTotal()/query.getSize());
         *    return PersonWrapper.build().pageVO(page);
         * }
         */
        //mapper
        /**
         * List<Person> selectPersonPage(@Param("start")Integer start, @Param("size") Integer size, @Param("person")Person person);
         */
        //xml
        /**
         * <select id="selectPersonPage" resultMap="personResultMap">
         *    select * from ryzt_pub_ry_info_td where 1 = 1
         *    <if test="person.gmsfhm != null and person.gmsfhm != ''">
         *       and gmsfhm like concat('%', #{person.gmsfhm}, '%')
         *    </if>
         *    order by gmsfhm
         *    limit #{start}, #{size}
         * </select>
         */
    }
}

5、根据身份证计算年龄

package com.ahc.demo;

import org.junit.Test;
import java.text.SimpleDateFormat;
import java.util.Date;

public class 根据身份证计算年龄 {
    @Test
    public void getNl() {
        String sfzhm = "130927199508250011";
        String temp = sfzhm == null ? null : sfzhm.substring(6,10);
        int i = howOld(temp);
        System.out.println("age:"+i);
    }

    public static int howOld(String birth) {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy");
        String format = sdf.format(new Date());
        int age = Integer.parseInt(format) - Integer.parseInt(birth);
        return age;
    }
}

6、日期转换和时间格式化

package com.ahc.demo;

import org.junit.Test;

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.Date;

public class 日期转换和时间格式化 {
    @Test
    public void date类型转换成localDateTime(){
        Date date = new Date();
        Instant instant = date.toInstant();
        ZoneId zoneId = ZoneId.systemDefault();
        LocalDateTime localDateTime = instant.atZone(zoneId).toLocalDateTime();
        System.out.println(localDateTime);
    }
    @Test
    public void LocalDateTime与String日期互相转换(){
        DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");//定义时间格式
        LocalDateTime time = LocalDateTime.now();//拿到现在的时间
        String localTime = df.format(time);//现在的时间转化为String类型
        LocalDateTime ldt = LocalDateTime.parse(localTime, df);//把刚刚转化的String类型再转为LocalDateTime类型
    }
    @Test
    public void 获取系统当前时间(){
        DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy年MM月dd日hh:mm");//时间格式化
        dateTimeFormatter.format(LocalDateTime.now());    //获取当前系统时间
    }

    //sql里格式化时间
    String str = "SELECT DATE_FORMAT(create_time,'%Y-%m-%d %h:%m:%s') FROM `test`";

    //xml里时间对比
    /**
     <if test="param.timeStart != null">
     and call_police_time >= #{param.timeStart}
     </if>
     <if test="param.timeEnd != null">
     and call_police_time <![CDATA[<=]]> #{param.timeEnd}
     */
}

7、校验手机号工具类

package com.ahc.untils;

import org.junit.Test;
import org.springframework.util.StringUtils;

import java.util.regex.Pattern;

/**
 * @Desc 用于后台手机号的验证工具类
 * @Date 2021/7/23
 * @Author ahc
 */
public class 校验手机号工具类 {
    //MobileUtils
    private static final String REGEX_MOBILE ="((\\+86|0086)?\\s*)((134[0-8]\\d{7})|(((13([0-3]|[5-9]))|(14[5-9])|15([0-3]|[5-9])|(16(2|[5-7]))|17([0-3]|[5-8])|18[0-9]|19(1|[8-9]))\\d{8})|(14(0|1|4)0\\d{7})|(1740([0-5]|[6-9]|[10-12])\\d{7}))";

    /**
     * 判断是否是手机号
     * @param tel 手机号
     * @return boolean true:是  false:否
     */
    public static boolean isMobile(String tel) {
        if (StringUtils.isEmpty(tel)){ return false;}
        return Pattern.matches(REGEX_MOBILE, tel);
    }
    @Test
    public void phone(){
        String str = "18830430881";
        System.out.println(str+":"+isMobile(str));
        //错误
        String strF = "123456";
        System.out.println(strF+":"+isMobile(strF));
    }
}

8、自动生成编号工具类

package com.ahc.untils;

import org.junit.Test;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.atomic.AtomicInteger;

public class 自动生成编号工具类 {
    //SerialRandom
    private static final AtomicInteger COUNT = new AtomicInteger();

    public static String createRand() {
        DateFormat df = new SimpleDateFormat("yyMMddHHmmss");
        String format = df.format(new Date());
        long time = Long.parseLong(format);
        if (time < -1) {
            time = -1;
        }

        return String.valueOf(time * 10000000 + COUNT.incrementAndGet());
    }

    public static String createRand(String prefix, String count, int length) {
        StringBuffer sb = new StringBuffer();
        sb.append(prefix).append(new SimpleDateFormat("yyyyMMdd").format(new Date()));
        length = length - sb.length() - count.length();
        for(int i = length; i > 0; --i) {
            sb.append("0");
        }
        sb.append(count);
        return sb.toString();
    }

    @Test
    public void 实现(){
        System.out.println(自动生成编号工具类.createRand());
        System.out.println(自动生成编号工具类.createRand("xx","10",15));
    }

}

9、字符串拼接去掉最后一个逗号

package com.ahc.demo;

import org.junit.Test;

import java.util.ArrayList;
import java.util.List;

public class 字符串拼接去掉最后一个逗号 {
    @Test
    public void ping(){
        String s1 = "我爱我家";
        String s2 = "我爱中国";
        String s3 = "我爱老婆";
        List<String> arrayList = new ArrayList<>();
        StringBuffer stringBuffer = new StringBuffer();
        String str = new String();
        arrayList.add(s1);  arrayList.add(s2);  arrayList.add(s3);
        System.out.println(arrayList);

        for (String arr : arrayList) {
            stringBuffer.append(arr).append(",");
        }

        System.out.println(stringBuffer);

        str = stringBuffer.deleteCharAt(stringBuffer.length()-1).toString();

        System.out.println(str);

    }
}

 10、非空判断总结工具

public boolean isNull(Object value) {
        if (value == null) {
            return true;
        } else if (value instanceof String) {
            if (((String) value).trim().replaceAll("\\s", "").equals("")) {
                return true;
            }
        } else if (value instanceof Collection) {
            if (((Collection) value).isEmpty()) {
                return true;
            }
        } else if (value.getClass().isArray()) {
            if (Array.getLength(value) == 0) {
                return true;
            }
        } else if (value instanceof Map) {
            if (((Map) value).isEmpty()) {
                return true;
            }
        } else {
            return false;
        }
        return false;

    }