自定义参数解析器,翻译实体属性

向右看齐 2024-04-17 06:15 69阅读 0赞

### 一、需求背景 ###

统计一个产品的数据，需要根据用户传递的、约定的枚举类型的值，来确定统计维度。  
刚开始，打算使用的是实体类型的`getter`、`setter`方式翻译用户传递的枚举值;但是,在获取翻译后的统计维度的时候,发现无法翻译/翻译失败了,于是换个方式,使用`自定义参数解析器`的方式来处理这个需求.

### 二、具体实现 ###

#### 1.实体类型 ####

package xxx.operator.qo;
    
    import com.fasterxml.jackson.annotation.JsonFormat;
    import com.fasterxml.jackson.annotation.JsonIgnore;
    import com.fasterxml.jackson.annotation.JsonProperty;
    import lombok.Data;
    import lombok.Getter;
    import lombok.NoArgsConstructor;
    import lombok.Setter;
    
    import java.util.Date;
    import java.util.List;
    
    /**
     * Author:   wxz
     * Date:     2023.11.1 9:08
     * Description: 小贷数据分析查询条件
     */
    @Data
    @NoArgsConstructor
    public class PettyLoanStatisticsQuery {
        
        /**
         * 开始日期
         */
        @Getter
        @Setter
        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern="yyyy-MM-dd")
        private Date startDate;
        /**
         * 结束日期
         */
        @Getter
        @Setter
        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern="yyyy-MM-dd")
        private Date endDate;
    
        /**
         * 前端传过来的统计标记
         */
        @Getter
        @Setter
        @JsonProperty(access = JsonProperty.Access.WRITE_ONLY)
        private int dimension;
        /**
         * 统计维度
         */
        @Getter
        @JsonIgnore
        private String orderBy;
        @Getter
        @Setter
        @JsonIgnore
        private List<String> organizeIds;
    
        public void setOrderBy(int dimension) {
        
            OrderByEnum of = OrderByEnum.of(dimension);
            if (of != null) {
        
                this.orderBy = of.getOrderBy();
            }
        }
    
        public PettyLoanStatisticsQuery(int dimension) {
        
            this.setOrderBy(dimension);
        }
    
        /**
         *统计维度枚举
         
        private enum OrderByEnum {
    
            /**
             * 区域
             */
            Area(0, "man.area_id"),
            /**
             * 组织机构
             */
            Organize(1, "duct.organize_id"),
            /**
             * 主体类型identity_type
             */
            IdentityType(2, "man.identity_type");
            @Getter
            @Setter
            private int code;
            /**
             * 统计维度枚举
             */
            @Getter
            @Setter
            private String orderBy;
    
            OrderByEnum(int code, String orderBy) {
        
                this.code = code;
                this.orderBy = orderBy;
            }
    
            /**
             * 根据code查询枚举
             */
            public static OrderByEnum of(int code) {
        
                OrderByEnum[] values = OrderByEnum.values();
                for (OrderByEnum a : values) {
        
                    if (a.code == code) {
        
                        return a;
                    }
                }
                return null;
            }
        }
    }

#### 2.自定义参数解析器 ####

package xxx.config;
    
    import com.ncjr.businessbase.operator.qo.FinancialLeasingStatisticsQuery;
    import com.ncjr.businessbase.operator.qo.PettyLoanStatisticsQuery;
    import org.springframework.core.MethodParameter;
    import org.springframework.http.HttpInputMessage;
    import org.springframework.http.converter.HttpMessageConverter;
    import org.springframework.web.bind.annotation.ControllerAdvice;
    import org.springframework.web.servlet.mvc.method.annotation.RequestBodyAdviceAdapter;
    
    import java.lang.reflect.Type;
    import java.util.Arrays;
    import java.util.List;
    
    /**
     * 自定义参数解析器,翻译租赁/小贷业务orderBy枚举
     */
    @ControllerAdvice
    public class FinancialStatisticsRequestBodyAdvice extends RequestBodyAdviceAdapter {
    
        /**
         * 需要处理的类
         */
        private final List<Object> targets = Arrays.asList(FinancialLeasingStatisticsQuery.class, PettyLoanStatisticsQuery.class);
    
        @Override
        public boolean supports(MethodParameter methodParameter, Type type,
                                Class<? extends HttpMessageConverter<?>> aClass) {
            // 判断是否需要对参数进行处理
            return targets.contains(methodParameter.getParameterType());
        }
    
        @Override
        public Object afterBodyRead(Object body, HttpInputMessage inputMessage, MethodParameter parameter,
                                    Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
            // 在读取请求体后执行自定义逻辑: 金融租赁
            if (body instanceof FinancialLeasingStatisticsQuery) {
                FinancialLeasingStatisticsQuery query = (FinancialLeasingStatisticsQuery) body;
                int dimension = query.getDimension();
                query.setOrderBy(dimension);
            }
            //小贷
            if (body instanceof PettyLoanStatisticsQuery) {
                PettyLoanStatisticsQuery query = (PettyLoanStatisticsQuery) body;
                int dimension = query.getDimension();
                query.setOrderBy(dimension);
            }
            return super.afterBodyRead(body, inputMessage, parameter, targetType, converterType);
        }
    }

通过上述自定义的参数解析器`翻译`枚举的 `code`属性值以后,就可以拿到对应的`orderBy`枚举值,然后查询的时候直接使用即可.  
(PS:参数解析器中,还可以使用多态等技术,优化处理各个if,简化处理逻辑).