com.gitee.beiding.template_excel.AutoIncrementNumber Maven / Gradle / Ivy

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package com.gitee.beiding.template_excel;

import java.util.*;
import java.util.stream.Collectors;

class AutoIncrementNumber {

    private Map maxValues;

    private W last;

    //
    void init(Map maxValues) {
        this.maxValues = maxValues;
        W f = last = new W();
        List list = maxValues.keySet().stream().sorted(Comparator.reverseOrder()).collect(Collectors.toList());
        f.name = list.get(0);
        last.value = -1;
        values.put(last.name, last.value);

        for (int i = 1; i < list.size(); i++) {//构建链结构
            W w = new W();
            w.name = list.get(i);
            w.next = f;
            f.pre = w;
            f = w;
            values.put(f.name, f.value);
        }

    }

    private Map values = new HashMap<>();

    boolean autoIncrement() {
        return autoIncrement(last);
    }

    //自增
    private boolean autoIncrement(W current) {

        current.value++;
        values.put(current.name, current.value);
        if (current.value <= maxValues.get(current.name)) {
            return true;
        } else {//自增已到达数当前位边界

            //已经到最大
            if (current.pre == null) {
                return false;
            } else {
                //重置当前位
                current.value = 0;//重置后
                values.put(current.name, current.value);
                //上一位自增
                return autoIncrement(current.pre);
            }
        }

    }

    Map getValues() {
        return values;
    }

    //位
    private class W {

        //名称
        String name;

        int value = 0;

        //下一位
        W next;

        //上一位
        W pre;
    }


}