springcboot分页助手pagehelper实现

1、 前台页面

<template>
    <div>
        <v-layout class="px-3 pb-2">
            <v-flex xs2>
                <v-btn color="info" small>新增</v-btn>
            </v-flex>
            <v-spacer/>
            <v-flex xs4>
                <v-text-field label="搜索" hide-details append-icon="search" v-model="key"></v-text-field>
            </v-flex>
        </v-layout>

        <v-data-table
                :headers="headers"
                :items="brands"
                :pagination.sync="pagination"
                :total-items="totalBrands"
                :loading="loading"
                class="elevation-1"
        >
            <template slot="items" slot-scope="props">
                <td class="text-xs-center">{{ props.item.id }}</td>
                <td class="text-xs-center">{{ props.item.name }}</td>
                <td class="text-xs-center"><image :src="props.item.image"/></td>
                <td class="text-xs-center">{{ props.item.letter }}</td>
                <td class="text-xs-center">
                    <v-btn flat icon color="info">
                        <v-icon>edit</v-icon>
                    </v-btn>
                    <v-btn flat icon color="red">
                        <v-icon>delete</v-icon>
                    </v-btn>
                </td>
            </template>
        </v-data-table>
    </div>
</template>

<script>
    export default {
        name: "MyBrand",
        data(){
            return {
                headers: [
                    { text: '品牌id', align: 'center', sortable: true, value: 'id'},
                    { text: '品牌名称', align: 'center', sortable: false, value: 'name'},
                    { text: '品牌LOGO', align: 'center', sortable: false, value: 'image'},
                    { text: '品牌首字母', align: 'center', sortable: true, value: 'letter'},
                    { text: '操作', align: 'center', sortable: false, value: 'caozuo'}
                ],
                brands: [],
                pagination: {},
                totalBrands: 0,
                loading: false,
                key: ''
            }
        },

        created(){
            //分页查询
            this.loadBrands();
        },

        watch: {
            //监控key(搜索条件)
            key(){
                this.pagination.page = 1;
                //this.loadBrands();
            },
            //深度监控pagination
            pagination: {
                deep: true,
                handler(){
                    this.loadBrands();
                }
            }
        },

        methods: {
            loadBrands(){
                // 开启进度条
                this.loading = true;
                this.$http.get('/item/brand/page?access-token=1', {
                    params: {
                        page: this.pagination.page,  //当前页
                        rows: this.pagination.rowsPerPage, //每页条数
                        sortBy: this.pagination.sortBy, //排序字段
                        desc: this.pagination.descending, //是否降序
                        key: this.key  //搜索条件
                    }
                }).then(resp => {
                    this.brands = resp.data.items;
                    this.totalBrands = resp.data.total;
                    //关闭进度条
                    this.loading = false;
                });
            }
        }
    }
</script>

<style scoped>

</style>

2、 后台controller

import cn.wangkf.common.vo.PageResult;
import cn.wangkf.item.pojo.Brand;
import cn.wangkf.item.service.BrandService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

/**
 * Created by wangk on 2019-01-05.
 */
@RestController
@RequestMapping("brand")
public class BrandController {

    @Autowired
    private BrandService brandService;

    //分页查询
    @GetMapping("page")
    public ResponseEntity<PageResult<Brand>> queryBrandByPage(
        //另一种方法就是放在一个对象里面
        @RequestParam(value = "page", defaultValue = "1") Integer page,
        @RequestParam(value = "rows", defaultValue = "5") Integer rows,
        @RequestParam(value = "sortBy", required = false) String sortBy,
        @RequestParam(value = "desc", defaultValue = "false") Boolean desc,
        @RequestParam(value = "key", required = false) String key
    ){
        return ResponseEntity.ok(brandService.queryBrandByPage(page,rows,sortBy,desc,key));
    }
}

3、 实现类

import cn.wangkf.common.enums.ExceptionEnum;
import cn.wangkf.common.exception.LgException;
import cn.wangkf.common.vo.PageResult;
import cn.wangkf.item.mapper.BrandMapper;
import cn.wangkf.item.pojo.Brand;
import cn.wangkf.item.service.BrandService;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;
import tk.mybatis.mapper.entity.Example;
import java.util.List;

/**
 * Created by wangk on 2019-01-05.
 */
@Service
public class BrandServiceImpl implements BrandService {

    @Autowired
    private BrandMapper brandMapper;

    //通用Mapper和分页助手pagehelper共同实现分页查询
    @Override
    public PageResult<Brand> queryBrandByPage(Integer page, Integer rows, String sortBy, Boolean desc, String key) {
        //1、分页
        PageHelper.startPage(page, rows);
        //2、过滤
        Example example = new Example(Brand.class);
        if (StringUtils.isNotBlank(key)) {
            //过滤条件
            example.createCriteria().orLike("name", "%"+key+"%").orEqualTo("letter", key.toUpperCase());
        }
        //3、排序
        if (StringUtils.isNotBlank(sortBy)) {
            String orderByClause = sortBy + (desc ? " DESC" : " ASC");
            example.setOrderByClause(orderByClause);
        }
        //4、查询（
        List<Brand> list = brandMapper.selectByExample(example);
        if (CollectionUtils.isEmpty(list)) { //异常处理
            throw new LgException(ExceptionEnum.BRAND_NOT_FOUND);
        }
        //分页助手解析list
        PageInfo<Brand> info = new PageInfo<>(list);
        return new PageResult<>(info.getTotal(), list);
    }
}

接口

import cn.wangkf.common.vo.PageResult;
import cn.wangkf.item.pojo.Brand;
/**
 * Created by wangk on 2019-01-05.
 */
public interface BrandService {

    /**
     *
     * @param page
     * @param rows
     * @param sortBy
     * @param desc
     * @param key
     * @return 分页查询结果
 */
public PageResult<Brand> queryBrandByPage(Integer page, Integer rows, String sortBy, Boolean desc, String key);
}

通用Mapper (需要在启动类里添加包件扫描)
@MapperScan(“cn.wangkf.item.mapper”)

import cn.wangkf.item.pojo.Brand;
import org.mybatis.spring.annotation.MapperScan;
import tk.mybatis.mapper.additional.idlist.SelectByIdListMapper;
import tk.mybatis.mapper.common.Mapper;

/**
 * Created by wangk on 2019-01-05.
 */
public interface BrandMapper extends Mapper<Brand> {
}

注：要实现sql控制台日志打印在yaml文件里引入依赖包即可

#sql在控制台打印便于调试找错
mybatis:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl