JAVA逻辑分页实现

import org.apache.poi.ss.formula.functions.T;
import org.springframework.util.CollectionUtils;

import java.util.List;

/**
 * @ClassName PageInfoConvent
 * @Description TODO
 * @Author braless
 * @Date 2021/4/7 18:17
 */
public class PageInfoConvent<T> {
    private int pageNum;
    private int pageSize;
    private int startRow;
    private int endRow;
    private int pages;
    private List<T> list ;
    public PageInfoConvent(int pageNum,int pageSize,List<T> totalList) {
        this.pageNum = pageNum<=1 ? 1:pageNum;
        this.pageSize = pageSize<=1 ? 1:pageSize;
        if(CollectionUtils.isEmpty(totalList)){
            return ;
        }
        int totalCount = totalList.size();
        if(totalCount<=pageSize){
            this.pages=1;
        }else{
            if(totalCount%pageSize>0){
                this.pages = totalCount/pageSize+1;
            }else{
                this.pages = totalCount/pageSize;
            }
        }
        this.startRow = this.pageNum > 0 ? (this.pageNum - 1) * this.pageSize : 0;
        this.endRow = this.startRow + this.pageSize * (this.pageNum > 0 ? 1 : 0);
        if(endRow>totalCount)endRow=totalCount;
        list = totalList.subList(this.startRow,this.endRow);
    }
//getter /setter 方法
    
}