java,jdbcTemplate分页实现

package com.example.rcadmin.model;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

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

@Data
@AllArgsConstructor
@NoArgsConstructor
public class PageList<T> {

    private int pageSize;   //单页最大数据量

    private int dataNumber; //Java类T 总的数据量

    private int pageNumber; //总的页数 总的页数=(总的数据量%单页最大数据量)==0?(总的数据量/单页最大数据量):((总的数据量/单页最大数据量)+1)

    private int currentPage; //当前页

    private List<T> dataList = new ArrayList<T>(); //当前页的全部数据

    public PageList(int currentPage,int pageSize,int dataNumber){
        this.currentPage = currentPage;
        this.pageSize = pageSize;
        pageNumber = (dataNumber%pageSize==0?(dataNumber/pageSize):(dataNumber/pageSize+1));
    }

}

package com.example.rcadmin.commonutils;

import com.example.rcadmin.model.PageList;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Repository;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

@Repository
public class pageTool<T> {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    public List<T> findAll(String sql, String TableName, rstoobj re) {
        if (sql.equals("")) sql = "select * from  " + TableName;
        return jdbcTemplate.query(sql, new RowMapper<T>() {
            @Override
            public T mapRow(ResultSet rs, int rowNum) throws SQLException {
                return (T) re.rtodata(rs);
            }
        });
    }

    //分页功能实现，获取分页数据
    public PageList<T> getListByPage(int currentPage, int pageSize, String findAllsql, String DataNumbersql, String ListByPagesql, String TableName, rstoobj re) {
        if (DataNumbersql.equals("")) DataNumbersql = "SELECT count(id) FROM " + TableName;
        if (ListByPagesql.equals("")) ListByPagesql = "SELECT * FROM " + TableName + " limit ?,?";

        //获取总数据量
        List<T> dataList = findAll(findAllsql, TableName, re);
        int dataNumber = dataList.size();
        //设置当前页面和每个页面的最大数据量
        PageList<T> dataPageList = new PageList<>(currentPage, pageSize, dataNumber);
        //获取所有的数据，得出总的数据量
        dataPageList.setDataNumber(jdbcTemplate.queryForObject(DataNumbersql, Integer.class));
        //根据当前页的情况来确定当前页的展示数据列表
        if (dataPageList.getCurrentPage() == dataPageList.getPageNumber()) {
            dataPageList.setDataList(jdbcTemplate.query(ListByPagesql, new RowMapper<T>() {
                @Override
                public T mapRow(ResultSet rs, int rowNum) throws SQLException {
                    return (T) re.rtodata(rs);
                }
            }, new Object[]{(currentPage - 1) * pageSize, dataPageList.getDataNumber() - (currentPage - 1) * pageSize}));
        } else {
            dataPageList.setDataList(jdbcTemplate.query(ListByPagesql, new RowMapper<T>() {
                @Override
                public T mapRow(ResultSet rs, int rowNum) throws SQLException {
                    return (T) re.rtodata(rs);
                }
            }, new Object[]{(currentPage - 1) * pageSize, pageSize}));
        }
        return dataPageList;
    }
}

package com.example.rcadmin.commonutils;

import java.sql.ResultSet;
import java.sql.SQLException;

public interface rstoobj<T> {
    T rtodata(ResultSet rs) throws SQLException;
}

package com.example.rcadmin.model;

import com.example.rcadmin.commonutils.rstoobj;
import com.example.rcadmin.enums.bl_apply_to;
import com.example.rcadmin.enums.bl_type;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.*;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Date;

//exrc数据库
@Data
@Builder
@ToString
@NoArgsConstructor //自动生成无参数构造函数。
@AllArgsConstructor //自动生成全参数构造函数
@ApiModel("未知")
public class blacklist implements rstoobj {
    @ApiModelProperty("id")
    private int id;
    @ApiModelProperty("未知属性")
    private bl_type type;
    @ApiModelProperty("未知属性")
    private String value;
    @ApiModelProperty("未知属性")
    private bl_apply_to apply_to;
    @ApiModelProperty("未知属性")
    private String exact_apply_to;
    @ApiModelProperty("应该是创建时间")
    private Date created_at;
    @ApiModelProperty("应该是更新时间")
    private Date updated_at;


    @Override
    public blacklist rtodata(ResultSet rs) throws SQLException {
        return new blacklist(rs.getInt("id"),bl_type.valueOfName(rs.getString("type")), rs.getString("value"), 		bl_apply_to.valueOfName(rs.getString("apply_to")),
                rs.getString("exact_apply_to"), rs.getDate("created_at"), rs.getDate("updated_at"));
    }
}

package com.example.rcadmin.service;

import com.example.rcadmin.commonutils.pageTool;
import com.example.rcadmin.dao.blacklistDao;
import com.example.rcadmin.model.PageList;
import com.example.rcadmin.model.blacklist;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class blacklistService {
    @Autowired
    private blacklistDao blacklistdao;
    @Autowired
    private pageTool pagetool;

    public PageList<blacklist> getListByPage(int currentPage, int pageSize) {
        return pagetool.getListByPage(2,10,"","","","blacklist",new blacklist());
    }
}

@PostMapping("/list")
   public R list() {
       blacklistservice.getListByPage(1,10);
       return null;
   }