Share JAP list paging query custom tools

JPA-based pagination tool that supports native sql associated multi-table, to generate the conditions needed only declaratively comment on dto.

Simplify development, improve development efficiency, in line with developers accustomed mybatis development habits.

1.自定义条件生成注解NativeQueryCondition 常量类OperatorConstant 

/**用于生成native sql条件的注解，作用于dto的字段
 * @author tlj
 * @date 2019/5/31
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface NativeQueryCondition {
    int order() default 0;
    String operator();
    String tbColumn() default "";
    String classColumn() default "";
    String tbAlias() default "";
    // 扩展类型，需要特殊处理的字段类型
    String expandType() default "";
}



/**
 * @author tlj
 * @date 2019/10/17
 */
public class OperatorConstant {
    private OperatorConstant(){}
    public static final String EQ = "=";
    public static final String GRATER_EQ = ">=";
    public static final String LESS_EQ = "<=";
    public static final String LIKE = "like";

}

Based approach BaseProfilePage 2. pagination

/**
 * @author tlj
 * @date 2019/7/13
 */
@Component
public class BaseProfilePage {
    @Autowired
    protected EntityManager entityManager;

    public <T> Page<T> queryPage(String sql, Map<String, Object> params, Pageable pageable, Class<T> clazz){
        Query query = entityManager.createNativeQuery(sql);
        PageUtil.setParameters(query, params);
        Integer currentPage = pageable.getPageNumber();
        int total = query.getResultList().size();
        int pageSize = pageable.getPageSize();
        int startCurrentPage = currentPage * pageSize;
        query.setFirstResult(startCurrentPage);
        query.setMaxResults(pageSize);
        query.unwrap(NativeQueryImpl.class).setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP);
        List<Map> list = query.getResultList();
        List<T> data = BeanUtil.convertListMapToListT(list, clazz);
        return (Page<T>) new PageImpl(data, pageable, total);
    }
    public <T> List<T> queryList(String sql, Map<String, Object> params, Class<T> clazz){
        Query query =entityManager.createNativeQuery(sql);
        PageUtil.setParameters(query, params);
        query.unwrap(NativeQueryImpl.class).setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP);
        return  BeanUtil.convertListMapToListT(query.getResultList(), clazz);
    }
}

3. The user dynamically constructed conditions sql tools NativeSqlBuilder

/**JPA native sql的封装
 * @author tlj
 * @date 2019/5/31
 */
@Getter
@Slf4j
public class NativeSqlBuilder {
    private final StringBuilder sql = new StringBuilder();
    private final List<String> where = Lists.newArrayList();
    private final Map<String, Object> params = Maps.newHashMap();

    /**
     *构建动态sql的条件（规则部分）
     * @param tableAliaName 表别名
     * @param dto 加了注解的DTO实例
     * @param <T>
     */
     public <T> NativeSqlBuilder buildConditionsStandard( String tableAliaName, T dto ){
         // 获取dto实例加了条件生成注解的字段
         List<Field> fs =Arrays.stream(dto.getClass().getDeclaredFields()).filter(it->it.isAnnotationPresent(NativeQueryCondition.class))
                 .sorted(Comparator.comparingInt(it->it.getAnnotation(NativeQueryCondition.class).order())).collect(Collectors.toList());
         fs.forEach(it->it.setAccessible(true));
         // 根据字段生成native sql的条件
         for(Field it : fs){
             Object columnObj = null;
             try {
                 columnObj = it.get(dto);
             } catch (IllegalAccessException e) {
                 log.error("{}",e);
             }
             if( null == columnObj || (String.class.equals(columnObj.getClass()) && StringUtils.isBlank(String.valueOf(columnObj))) ){
                 continue;
             }
             NativeQueryCondition condition = it.getAnnotation(NativeQueryCondition.class);
             buildFieldCondition(tableAliaName,columnObj,condition,it.getName());
         }
         return this;
     }
     private void buildFieldCondition(String tableAliaName, Object columnObj, NativeQueryCondition condition, String fieldName ){
         String tbColumn = condition.tbColumn();
         if(StringUtils.isBlank(tbColumn)){
             tbColumn =camel2Underline( fieldName );
         }
         String classColumn = condition.classColumn();
         if(StringUtils.isBlank(classColumn)){
             classColumn = fieldName;
         }
         if( StringUtils.isNotBlank(condition.tbAlias()) ){
             tableAliaName = condition.tbAlias();
         }
         where.add( tableAliaName+"." + tbColumn + " " + condition.operator() + ":" + classColumn );
         if( LocalDate.class.equals(columnObj.getClass()) && OperatorConstant.LESS_EQ.equals(condition.operator()) ){
             // 结束日期的<= 需要在原来基础上加1
             LocalDate localDate = (LocalDate)columnObj;
             params.put( classColumn, localDate.plusDays(1));
         }else{
             if("like".equals(condition.operator())){
                 params.put( classColumn, "%" + columnObj + "%");
             }else{
                 params.put( classColumn, columnObj);
             }
         }

     }

    /** 构建特殊条件（不规则部分，单个）
     *  where.add("store.status=:status");
     *  params.put("status", BaseStatusEnum.VALID.getCode());
     * @return
     */
     public NativeSqlBuilder buildConditionSpecial(String whereItem,String paramKey,Object paramValue){
         where.add( whereItem );
         params.put(paramKey, paramValue);
         return this;
     }


    public  NativeSqlBuilder joinWhereList(){
        if (!where.isEmpty()) {
            sql.append(" where ").append(String.join(" and ", where));
        }
         return this;
    }
    public  NativeSqlBuilder orderBy(String tabAlias,String orderBy, String  xsc){
        sql.append(" order by ").append(tabAlias).append(".").append(orderBy).append(" ").append(xsc);
         return this;
    }
    public  NativeSqlBuilder orderBy(String tabAlias,String orderBy, String  xsc,Class clazz){
        sql.append(" order by ").append(tabAlias).append(".");
        if (StringUtils.isNotBlank(orderBy) && StringUtils.isNotBlank(xsc)) {
            sql.append(ColumnUtil.getColumn(clazz,orderBy)).append(" ").append(xsc);
        } else {
            sql.append("date_created").append(" ").append("desc");
        }
         return this;
    }
    public NativeSqlBuilder append(String str){
        sql.append(str);
        return this;
    }

    /**
     * 驼峰法转下划线
     *
     * @param line
     *            源字符串
     * @return 转换后的字符串
     */
    private static String camel2Underline(String line) {
        if (line == null || "".equals(line)) {
            return "";
        }
        line = String.valueOf(line.charAt(0)).toUpperCase()
                .concat(line.substring(1));
        StringBuilder sb = new StringBuilder();
        Pattern pattern = Pattern.compile("[A-Z]([a-z\\d]+)?");
        Matcher matcher = pattern.matcher(line);
        while (matcher.find()) {
            String word = matcher.group();
            sb.append(word.toUpperCase());
            sb.append(matcher.end() == line.length() ? "" : "_");
        }
        return sb.toString();
    }

    @Override
    public String toString() {
        return sql.toString();
    }
}

4. Write the real paging business method (inherited BaseProfilePage)

/**
 * @author tlj
 * @date 2019/6/17
 */
@Component
public class LineMainProfilePage extends BaseProfilePage{

    /**
     * 后台管理系统--业务线列表分页
     */
    @Transactional(readOnly = true)
    public Page<LinePageItemDTO> page(LinePageQueryDTO req) {
        NativeSqlBuilder nativeSqlBuilder = new NativeSqlBuilder();
        nativeSqlBuilder.append("SELECT line.id, line.`code`, line.bus_status busStatus, line.`name`, line.first_category firstCategory, line.second_category secondCategory, c1.`name` firstCategoryName, c2.`name` secondCategoryName FROM t_line_main line LEFT JOIN t_base_category c1 ON line.first_category = c1.id LEFT JOIN t_base_category c2 ON line.second_category = c2.id");
        // 动态sql
        nativeSqlBuilder.buildConditionsStandard("line",req ).joinWhereList()
                .orderBy("line",req.getOrderBy(),req.getXsc(),LineMainEntity.class);
        Page<LinePageItemDTO> page = super.queryPage(nativeSqlBuilder,req.getPage(),LinePageItemDTO.class);
        page.getContent().forEach(it->it.setBuStatusName(StepEnum.map.get(it.getBusStatus())));
        return page;
    }


}

5. DTO parameter query statement @NativeQueryCondition (operator = OperatorConstant.LIKE) supports fuzzy match exactly equal. The default database field names and field names are underlined hump relationship, you can also customize correspondence. See NativeQueryCondition and NativeSqlBuilder code. Tools can extend itself, now tools temporarily to meet the needs of the project.

/**
 * @author tlj
 * @date 2019/10/17
 */
@Data
@ApiModel
public class LinePageQueryDTO extends QueryPagingDTO implements Serializable {
    private static final long serialVersionUID = -1181156497389378741L;
    @ApiModelProperty(value = "业务线名称")
    @NativeQueryCondition(operator = OperatorConstant.LIKE)
    private String name;
    @ApiModelProperty(value = "业务线代码")
    @NativeQueryCondition(operator = OperatorConstant.LIKE)
    private String code;

    @ApiModelProperty(value = "状态:0已禁用1已启用")
    @NativeQueryCondition(operator = OperatorConstant.EQ)
    @EnumValidator(value = BusStatusEnum.class,message = "状态可选值:0已禁用1已启用")
    private Integer busStatus;


}

6. Other basic pager DTO QueryPagingDTO

@ApiModel
public class QueryPagingDTO implements Serializable {
    private static final long serialVersionUID = -1500626651502386429L;
    @ApiModelProperty("当前页码（ 默认从1开始，后台将自动减1）")
    private Integer currentPage = 0;
    @ApiModelProperty("每页数量 ( 默认每一页10条)")
    protected Integer pageSize = 10;
    @ApiModelProperty("排序字段")
    protected String orderBy = "id";
    @ApiModelProperty("升序 ASC / 降序 DESC")
    protected String xsc;

    @JsonIgnore
    public Pageable getPage() {
        Sort sort;
        if ("asc".equalsIgnoreCase(this.xsc)) {
            sort = new Sort(Direction.ASC, new String[]{this.orderBy});
        } else {
            sort = new Sort(Direction.DESC, new String[]{this.orderBy});
        }

        return PageRequest.of(this.currentPage, this.pageSize, sort);
    }

    public void setCurrentPage(Integer currentPage) {
        if (currentPage == 0) {
            this.currentPage = 0;
        } else {
            this.currentPage = currentPage - 1;
        }

    }

    public void setCurrentPageActual(Integer currentPage) {
        this.currentPage = currentPage;
    }

    public QueryPagingDTO() {
    }

    public Integer getCurrentPage() {
        return this.currentPage;
    }

    public Integer getPageSize() {
        return this.pageSize;
    }

    public String getOrderBy() {
        return this.orderBy;
    }

    public String getXsc() {
        return this.xsc;
    }

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

    public void setOrderBy(final String orderBy) {
        this.orderBy = orderBy;
    }

    public void setXsc(final String xsc) {
        this.xsc = xsc;
    }

    public boolean equals(final Object o) {
        if (o == this) {
            return true;
        } else if (!(o instanceof QueryPagingDTO)) {
            return false;
        } else {
            QueryPagingDTO other = (QueryPagingDTO)o;
            if (!other.canEqual(this)) {
                return false;
            } else {
                label59: {
                    Object this$currentPage = this.getCurrentPage();
                    Object other$currentPage = other.getCurrentPage();
                    if (this$currentPage == null) {
                        if (other$currentPage == null) {
                            break label59;
                        }
                    } else if (this$currentPage.equals(other$currentPage)) {
                        break label59;
                    }

                    return false;
                }

                Object this$pageSize = this.getPageSize();
                Object other$pageSize = other.getPageSize();
                if (this$pageSize == null) {
                    if (other$pageSize != null) {
                        return false;
                    }
                } else if (!this$pageSize.equals(other$pageSize)) {
                    return false;
                }

                Object this$orderBy = this.getOrderBy();
                Object other$orderBy = other.getOrderBy();
                if (this$orderBy == null) {
                    if (other$orderBy != null) {
                        return false;
                    }
                } else if (!this$orderBy.equals(other$orderBy)) {
                    return false;
                }

                Object this$xsc = this.getXsc();
                Object other$xsc = other.getXsc();
                if (this$xsc == null) {
                    if (other$xsc != null) {
                        return false;
                    }
                } else if (!this$xsc.equals(other$xsc)) {
                    return false;
                }

                return true;
            }
        }
    }

    protected boolean canEqual(final Object other) {
        return other instanceof QueryPagingDTO;
    }

    public int hashCode() {
        int PRIME = true;
        int result = 1;
        Object $currentPage = this.getCurrentPage();
        int result = result * 59 + ($currentPage == null ? 43 : $currentPage.hashCode());
        Object $pageSize = this.getPageSize();
        result = result * 59 + ($pageSize == null ? 43 : $pageSize.hashCode());
        Object $orderBy = this.getOrderBy();
        result = result * 59 + ($orderBy == null ? 43 : $orderBy.hashCode());
        Object $xsc = this.getXsc();
        result = result * 59 + ($xsc == null ? 43 : $xsc.hashCode());
        return result;
    }

    public String toString() {
        return "QueryPagingDTO(currentPage=" + this.getCurrentPage() + ", pageSize=" + this.getPageSize() + ", orderBy=" + this.getOrderBy() + ", xsc=" + this.getXsc() + ")";
    }
}