【记录】mybatis-plus 根据自定义注解反射实现条件拼接查询

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
        </dependency>
        <!--swagger2-->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
        </dependency>

import com.supconit.its.generator.enums.QueryWapperEnum;
import org.springframework.stereotype.Indexed;

import java.lang.annotation.*;


@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Indexed
public @interface QueryWapper {

    String field() default "";

    QueryWapperEnum queryWapperEnum() default QueryWapperEnum.EQ ;
}

/**
 * @Description 查询枚举类
 * @Date 2020-07-16 16:10
 */
public enum QueryWapperEnum {

    LIKE(1),EQ(2);

    private final int value;

    QueryWapperEnum(int value) {
        this.value = value;
    }

    public int value() {
        return this.value;
    }
}

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import io.swagger.annotations.ApiParam;
import com.baomidou.mybatisplus.annotation.TableField;
import com.xx.xx.generator.stereotype.QueryWapper;
import com.xx.xx.generator.enums.QueryWapperEnum;

@Data
@ApiModel(value = "XX", description = "XX")
public class PersBO {


 @ApiModelProperty(value = " 姓名  ")
 @TableField(value = "name ")
 @ApiParam(value = " 姓名 ",example = "",required = false)
 @QueryWapper(field = "name",queryWapperEnum = QueryWapperEnum.EQ )
 private String name;

/**
 * 当前页数
 */
@ApiModelProperty(value = "当前页数", example = "1", required = true)
private Integer current;
/**
 * 每页条数
 */
@ApiModelProperty(value = "每页条数", example = "10", required = true)
private Integer size;
}

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.supconit.its.generator.enums.QueryWapperEnum;
import com.supconit.its.generator.stereotype.QueryWapper;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.util.ObjectUtils;

import java.lang.reflect.Field;

import static org.apache.commons.lang3.reflect.MethodUtils.invokeMethod;

/**
 * @Description 拼接查询条件工具类
 */
public class QueryWrapperUtil {

    /**
     * 拼接查询条件
     *
     * @param queryWrapper 条件对象
     * @param obj          数据实体
     * @return void 返回参数说明
     * @exception/throws
     */
    public static void convertQuery(QueryWrapper queryWrapper, Object obj) {
        Class clazz = obj.getClass();
        try {
            // 反射遍历属性
            for (Field field : clazz.getDeclaredFields()) {
                // 获取属性名
                String fieldname = field.getName();
                // 抑制Java对修饰符的检查
                field.setAccessible(true);
                // 获取属性值
                Object fieldValue =  field.get(obj);
//            String fieldValue = getFieldValue(obj ,field.getName()).toString();
                // 查询注解
                QueryWapper queryWapperAnnotation = AnnotationUtils.getAnnotation(field, QueryWapper.class);
               if(ObjectUtils.isEmpty(queryWapperAnnotation)){
                   continue;
               }
                String fieldName = queryWapperAnnotation.field();
                // 获取枚举
                QueryWapperEnum queryWapperEnum = queryWapperAnnotation.queryWapperEnum();
                // 拼接查询条件
                switch (queryWapperEnum) {
                    case EQ:
                        queryWrapper.eq(!ObjectUtils.isEmpty(fieldValue), fieldName, fieldValue);
                        break;
                    case LIKE:
                        queryWrapper.like(!ObjectUtils.isEmpty(fieldValue), fieldName, fieldValue);
                        break;
                    default:
                        break;
                }
            }
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取属性名
     *
     * @exception/throws
     */
    private static String getFieldValue(Object owner, String fieldName) {
        try {
            return invokeMethod(owner, fieldName, null).toString();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;
import com.xx.xx.PersDTO;

/**
 * <p>
 * Mapper 接口
 * </p>
 *
 */
@Mapper
public interface PersMapper extends BaseMapper<PersDTO> {

}

 Page<PersDTO> page = new Page(persBO.getCurrent(), persBO.getSize());
 // 拼接查询条件
 QueryWrapper<PersDTO> persDTOQueryWrapper = new QueryWrapper<>();
 QueryWrapperUtil.convertQuery(persDTOQueryWrapper,persBO);
 IPage<PersDTO> iPage = persMapper.selectPage(page, persDTOQueryWrapper);
  page.setRecords(iPage.getRecords());