SpringBoot CRUD 简易模板后端

以单表为例。
数据库表:
sp_system_config

实体类:

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonInclude.Include;
import cn.afterturn.easypoi.excel.annotation.Excel;
import lombok.Getter;
import lombok.Setter;

@JsonInclude(Include.NON_NULL)
@TableName("sp_system_config")
@Getter
@Setter
public class SystemConfig {
    @TableId(
            type = IdType.AUTO
    )
    private Long id;
    @TableField("configName")
    @Excel(name = "配置名")
    private String configName;
    @TableField("configCName")
    @Excel(name = "配置中文名")
    private String configCName;
    @TableField("configValue")
     @Excel(name = "配置值")
    private String configValue;
     @Excel(name = "备注")
    private String remark;
     @Excel(name = "单位")
    private String unit;
}

基本的控制器

@RequestMapping("/systemConfig")
@RestController
public class SystemConfigController {

    @Resource
    private SystemConfigService systemConfigService;
 }   

基本的service

@Service
public class SystemConfigService {

    @Resource
    private SystemConfigMapper systemConfigMapper;
}    

基本的mapper接口

//实体类所在包
import cn.product.entity.SystemConfig;
import org.apache.ibatis.annotations.Param;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import java.util.List;


public interface SystemConfigMapper extends LocalBaseMapper<SystemConfig> {
}

基本的mapper xml:(注意mapper的位置)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.product.mapper.SystemConfigMapper">
</mapper>

功能1:分页

分页返回的工具类 PageResult

import java.util.List;

public class PageResult<T>  {

    //当前页数
    private Long pageIndex;

    //每页数据数
    private Long pageSize;

    //总条数
    private Long totalCount;

    //总页数
    private Long totalPage;

    //列表数据
    private List<T> list;

    //统计数据
    private Object countData;

    public Long getPageIndex() {
        return pageIndex;
    }

    public void setPageIndex(Long pageIndex) {
        this.pageIndex = pageIndex;
    }

    public Long getPageSize() {
        return pageSize;
    }

    public void setPageSize(Long pageSize) {
        this.pageSize = pageSize;
    }

    public Long getTotalCount() {
        return totalCount;
    }

    public void setTotalCount(Long totalCount) {
        this.totalCount = totalCount;
    }

    public Long getTotalPage() {
        if(this.getTotalCount()==null || this.getTotalCount()<=0){
            return 0L;
        }
        if(this.getTotalCount()%this.getPageSize()==0){
            return this.getTotalCount()/this.getPageSize();
        }else{
            return this.getTotalCount()/this.getPageSize()+1;
        }
    }

    public void setTotalPage(Long totalPage) {
        this.totalPage = totalPage;
    }

    public List<T> getList() {
        return list;
    }

    public void setList(List<T> list) {
        this.list = list;
    }

    public Object getCountData() {
        return countData;
    }

    public void setCountData(Object countData) {
        this.countData = countData;
    }
}

分页工具:CommonPage

public class CommonPage {

    //当前页码
    private Integer pageIndex = 1;
    //每页显示条数
    private Integer pageSize = 10;

    private Long skipNum ;

    public Integer getPageIndex() {
        if(pageIndex==null || pageIndex<=0){
            return 10;
        }
        return pageIndex;
    }

    public void setPageIndex(Integer pageIndex) {
        this.pageIndex = pageIndex;
    }

    public Integer getPageSize() {
        if(pageSize==null || pageSize<=0){
            return 1;
        }
        return pageSize;
    }

    public void setPageSize(Integer pageSize) {
        this.pageSize = pageSize;
    }

    public Long getSkipNum() {
        return (long)(this.getPageSize()*(this.getPageIndex()-1));
    }

    public void setSkipNum(Long skipNum) {
        this.skipNum = skipNum;
    }
}

查询参数实体类:SystemConfigQueryVo

//引用上面的
import cn.product.dto.CommonPage;
import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
public class SystemConfigQueryVo extends CommonPage {


    private String configName;

    private String configCName;

    private String configValue;
}

返回的实体类就是实体类。不用再写成VO。
分页代码 :
controller -> service -> mapper

    //controller代码
    @ApiOperation(value = "分页查询系统配置")
    @PostMapping("/page")
    @ResponseBody
    public PageResult<SystemConfig> page(SystemConfigQueryVo dto) {
        return systemConfigService.page(dto);
    }

    //service代码
    public PageResult<SystemConfig> page(SystemConfigQueryVo dto) {
     
        PageResult<SystemConfig> page = new PageResult<>();
        Long count = (long) systemConfigMapper.listCount(dto).size();
        page.setTotalCount(count);
        page.setPageSize((long) dto.getPageSize());
        page.setPageIndex((long) dto.getPageIndex());
        if (count == 0) {
            page.setList(new ArrayList<>());
            return page;
        }
        //设置值
        List<SystemConfig> list = systemConfigMapper.list(dto);
        page.setList(list);
        return page;
    }

    //mapper 接口代码
    List<SystemConfig> listCount(@Param("dto") SystemConfigQueryVo dto);

    List<SystemConfig> list(@Param("dto") SystemConfigQueryVo dto);
    
    //mapper xml代码
      <select id="listCount" resultType="cn.product.entity.SystemConfig">
        select * from sp_system_config
        <where>
            <if test="dto.configName !=null and dto.configName != '' ">
                and configName like concat( '%',#{dto.configName}, '%')
            </if>
            <if test="dto.configCName !=null and dto.configCName != '' ">
                and configCName like concat( '%',#{dto.configCName}, '%')
            </if>
            <if test="dto.configValue !=null and dto.configValue != '' ">
                and configValue like concat( '%',#{dto.configValue}, '%')
            </if>
        </where>
    </select>
    <select id="list" resultType="cn.product.entity.SystemConfig">

        select * from sp_system_config
        <where>
            <if test="dto.configName !=null and dto.configName != '' ">
                and configName like concat( '%',#{dto.configName}, '%')
            </if>
            <if test="dto.configCName !=null and dto.configCName != '' ">
                and configCName like concat( '%',#{dto.configCName}, '%')
            </if>
            <if test="dto.configValue !=null and dto.configValue != '' ">
                and configValue like concat( '%',#{dto.configValue}, '%')
            </if>
        </where>
        limit #{dto.skipNum},#{dto.pageSize}
    </select>
    
    

功能2:增加/编辑

 //controller代码
     @ApiOperation(value = "增加系统配置")
    @PostMapping("/add")
    public void add(@RequestBody SystemConfig systemConfig) {
        systemConfigService.add(systemConfig);
    }

    @ApiOperation(value = "编辑系统配置")
    @PostMapping("/update")
    public void update(@RequestBody SystemConfig systemConfig) {
        systemConfigService.update(systemConfig);
    }
 //service代码
    public void add(SystemConfig systemConfig) {
        if (StringUtils.isEmpty(systemConfig.getConfigName())) {
            throw new BusinessException("请输入配置属性!");
        }
        systemConfig.setConfigName(systemConfig.getConfigName().trim());
        SystemConfig oldConfig = systemConfigMapper.selectOne(Wrappers.<SystemConfig>lambdaQuery().eq(SystemConfig::getConfigName, systemConfig.getConfigName()));
        if (oldConfig != null) {
            throw new BusinessException("该配置已经存在!");
        }
        systemConfigMapper.insert(systemConfig);
    }

    public void update(SystemConfig systemConfig) {
        if (systemConfig.getId() == null) {
            throw new BusinessException("请选择配置属性进行编辑!");
        }
        if (StringUtils.isEmpty(systemConfig.getConfigName())) {
            throw new BusinessException("请输入配置属性!");
        }
        systemConfig.setConfigName(systemConfig.getConfigName().trim());
        SystemConfig oldConfig = systemConfigMapper.selectById(systemConfig.getId());
        if (oldConfig == null) {
            throw new BusinessException("该配置不存在!");
        }
        systemConfigMapper.update(null, Wrappers.<SystemConfig>lambdaUpdate()
                .eq(SystemConfig::getId, systemConfig.getId())
                .set(SystemConfig::getConfigName, systemConfig.getConfigName())
                .set(SystemConfig::getConfigCName, systemConfig.getConfigCName())
                .set(SystemConfig::getConfigValue, systemConfig.getConfigValue())
                .set(SystemConfig::getRemark, systemConfig.getRemark())
                .set(SystemConfig::getUnit, systemConfig.getUnit())
        );
    }
 

功能3:删除

//controller
    @ApiOperation(value = "删除系统配置")
    @GetMapping("/delete")
    public void delete(Integer id) {
        systemConfigService.delete(id);
    }
//service 
public void delete(Integer id) {
        systemConfigMapper.deleteById(id);
    }

功能4:导出

    @RequestMapping(value = "/export", method = RequestMethod.POST)
    @ApiOperation(value = "导出")
    public void export(@RequestBody SystemConfigQueryVo dto, HttpServletResponse resp) throws Exception {
        exportBaseInfo(resp);
        dto.setPageIndex(1);
        dto.setPageSize(Integer.MAX_VALUE);
        //像分页那样获取信息
        List<SystemConfig> list = systemconfigService.page(dto).getList();
        Workbook workbook = ExcelExportUtil.exportExcel(new ExportParams(),
                SystemConfig.class,
                list);
        workbook.write(resp.getOutputStream());
    }

       private static void exportBaseInfo(HttpServletResponse resp) throws UnsupportedEncodingException {
        resp.setCharacterEncoding("UTF-8");
        String filename = new String("系统配置".getBytes("gbk"), "iso8859-1");
        resp.setHeader("Content-Disposition", "attachment; filename=\"" + filename + ".xlsx\"");
        resp.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        resp.addHeader("Access-Control-Expose-Headers", "Content-Disposition");
        resp.addHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS");
        resp.addHeader("Access-Control-Allow-Headers",
                "Content-Type,X-Requested-With,accept,Origin,Access-Control-Request-Method,Access-Control-Request-Headers,token");
    }

功能5: 导入:

easypoi-base 4.2.0

 @PostMapping("/import")
    public voidimport(@RequestParam(value = "file") MultipartFile file) {
        try {
            ImportParams params = new ImportParams();
            params.setTitleRows(0);
            params.setHeadRows(1);
            List<SystemConfig> list = ExcelImportUtil.importExcel(file.getInputStream(), SystemConfig.class, params);

            if (list.isEmpty()) {
                throw new CustomServiceException("Excel表格中没有数据");
            }
            //处理导入的数据
            String exceptionMsg = systemConfigService.importData(list);
            if (!StringUtils.isEmpty(exceptionMsg)) {
               throw new CustomServiceException("Excel表格中没有数据");
            }

        } catch (Exception e) {
           throw new CustomServiceException(e.getMessage());
        }
    }