生成自增id

 1.批量生成自增类型流水号id

package com.test.demo.config;import java.util.ArrayList;
import java.util.List;/*** 导入导出工具类ExcelUtil** @author zhuochao* @date 2020/10/22*/
public class ExcelUtil {//a 表示你想生成多少个主键的数量public static List<String> getnum(int a) {List<String> list = new ArrayList<String>();String str = "";for (int i = 1; i <= a; i++) {str = String.format("%04d", i);list.add(str);}return list;}public static void main(String[] args) {List<String> list = new ArrayList<String>();String m = "ER-";for (int i = 0; i < 2; i++) {String format = String.format("%05d", i);list.add(format);System.out.println(m + format);}System.out.println(getnum(5));}
}

2.生成单条的自增型流水号id

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package com.mw.framework.util;import java.util.concurrent.atomic.AtomicInteger;public class SerialNumberUtils {public static String[] sn(int len,Integer i,String driver,String prefix,int limited){String[] result = new String[4];AtomicInteger z = new AtomicInteger(i);AtomicInteger x = new AtomicInteger(i);driver = driver==null?"":driver;prefix = prefix==null||prefix.equals("null")?"":prefix;//1.判断流水号长度是否大于约定长度if(z.toString().length()<=(len-driver.length())){if(Integer.valueOf(x.incrementAndGet()).toString().length()>(len-driver.length())||(driver.length()>limited && limited!=-1)){System.out.println("默认索引超出范围,需从字母A开始重新一轮的流水号");//2.如果流水号+字母长度超过了最大限度修改新的长度//len=String.valueOf(x.get()).length();int temp  = String.valueOf(x.get()).length();AtomicInteger atomicInteger = new AtomicInteger(0);char[] charArray = driver.toCharArray();for (char c : charArray) {if(c=='Z'){atomicInteger.getAndIncrement();}}if((temp+driver.length()>len && atomicInteger.intValue()==driver.length() && driver.length()>0) ||(driver.length()>limited && limited!=-1)){System.out.println("如果流水号+字母长度超过了最大限度修改新的长度,并重新开始一轮+1的流水号");len++;driver="";}else{driver = driverCheck(driver,len,limited);if(driver.equals(".N")){driver = "";}}z.set(0);}String current = String.format("%0"+(len-driver.length())+"d",z.incrementAndGet());result[0]=prefix+driver+current;result[1]=driver;result[2]=String.valueOf(len);result[3]=String.valueOf(z.get());System.out.println(prefix+driver+current);}else{System.out.println("输入不合法！");}return result;}/*** 字母有效检查* 1.检查字母是否都为Z* 2.检查字母长度* @param driver* @param len* @return*/public static String driverCheck(String driver,int len,int limited){if(driver!=null && driver.length()>0){AtomicInteger z = new AtomicInteger(0);char[] charArray = driver.toCharArray();for (char c : charArray) {if(c=='Z'){z.getAndIncrement();}}if(z.intValue()==driver.length()){String result = "";if(z.intValue()==len && z.intValue()>limited){//如所有字母都为Z，并且长度达到限定长度，返回.NSystem.out.println("如所有字母都为Z，并且长度达到限定长度，返回.N");result = ".N";}else if(z.intValue()<len-1 && z.intValue()<=limited){System.out.println("如果所有字母都为Z，但长度未达到限定长度,直接递增");result = driver(driver+"@");}return result;}else{System.out.println("以上两个条件都不满足，则直接递增");return driver(driver);}/*if(z.intValue()==driver.length() && z.intValue()==len){//如所有字母都为Z，并且长度达到限定长度，返回.Nreturn ".N";}else if(z.intValue()==driver.length() && z.intValue()<len){//如果所有字母都为Z，但长度未达到限定长度，则在调用字母递增方法之前加入@用以递增ASystem.out.println(z.intValue());System.out.println(driver.length());return driver2(driver);}else{//以上两个条件都不满足，则直接递增return driver2(driver);}*/}else{return "A";}}/*** 字母递增* @param driver* @return*/public static String driver(String driver){if(driver!=null && driver.length()>0){char[] charArray = driver.toCharArray();boolean bool = false;for(int i = charArray.length-1;i>-1;i--){if(charArray[i]=='Z'){if(i==charArray.length-1){charArray[i]='A';bool = true;}else{if(bool==true){AtomicInteger atomic = new AtomicInteger(charArray[i]);int val = atomic.incrementAndGet();if(90>=val){charArray[i]=(char) val;bool = false;}else{charArray[i]='A';bool = true;}}}}else{if(bool==true || (i==charArray.length-1)){AtomicInteger atomic = new AtomicInteger(charArray[i]);int val = atomic.incrementAndGet();if(90>=val){charArray[i]=(char) val;bool = false;}else{charArray[i]='A';bool = true;}}}}return String.valueOf(charArray);}else{return "A";}}public static void main(String[] args) {String[] s_= sn(5,9, "ZYAS","",-1);for (String string : s_) {System.out.println(string);}}
}