这是我的通用方法
package com.spark.bitrade.service.Base;
import com.querydsl.core.Tuple;
import com.querydsl.core.types.EntityPath;
import com.querydsl.core.types.Expression;
import com.querydsl.core.types.OrderSpecifier;
import com.querydsl.core.types.Predicate;
import com.querydsl.core.types.dsl.EntityPathBase;
import com.querydsl.jpa.impl.JPAQuery;
import com.querydsl.jpa.impl.JPAQueryFactory;
import com.spark.bitrade.pagination.PageListMapResult;
import com.spark.bitrade.pagination.PageResult;
import com.spark.bitrade.pagination.QueryDslContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
/**
* @author rongyu
* @description
* @date 2018/1/18 10:29
*/
@Component
public class BaseService {
//JPA查询工厂
@Autowired
protected JPAQueryFactory queryFactory;
@Autowired
protected JPAQueryFactory jpaQueryFactory;
@Autowired
@PersistenceContext
protected EntityManager em;
/**
* 查询列表
*
* @param pageNo 分页参数
* @param pageSize 分页大小
* @param predicateList 查询条件
* @param entityPathBase 查询表
* @param orderSpecifierList 排序条件
* @return
*/
@Transactional(readOnly = true)
public PageResult queryDsl(Integer pageNo, Integer pageSize, List predicateList, EntityPathBase entityPathBase, List orderSpecifierList) {
List list;
//查询表
JPAQuery jpaQuery = jpaQueryFactory.selectFrom(entityPathBase);
//查询条件
if (predicateList != null && predicateList.size() > 0)
jpaQuery.where(predicateList.toArray(new Predicate[predicateList.size()]));
//排序方式
if (orderSpecifierList != null && orderSpecifierList.size() > 0)
jpaQuery.orderBy(orderSpecifierList.toArray(new OrderSpecifier[orderSpecifierList.size()]));
//分页查询
if (pageNo != null && pageSize != null) {
list = jpaQuery.offset((pageNo - 1) * pageSize).limit(pageSize).fetch();
} else {
list = jpaQuery.fetch();
}
return new PageResult<>(list, pageNo, pageSize, jpaQuery.fetchCount());
}
/**
* 查询单个
*
* @param predicate 查询条件
* @param entityPathBase 查询表
* @return
*/
@Transactional(readOnly = true)
public T queryOneDsl(Predicate predicate, EntityPathBase entityPathBase) {
return jpaQueryFactory.selectFrom(entityPathBase).where(predicate).fetchFirst();
}
//多表联合查询
/**
*
* @param qdc queryDsl 查询对象
* @param pageNo
* @param pageSize
* @return
*/
@Transactional(readOnly = true)
public PageListMapResult queryDslForPageListResult(QueryDslContext qdc, Integer pageNo, Integer pageSize) {
JPAQuery jpaQuery = queryFactory.select(qdc.expressionToArray())
.from(qdc.entityPathToArray())
.where(qdc.predicatesToArray());
List tuples = jpaQuery.orderBy(qdc.orderSpecifiersToArray())
.offset((pageNo - 1) * pageSize).limit(pageSize)
.fetch();
List> list = new LinkedList<>();//返回结果
//封装结果
for (int i = 0; i < tuples.size(); i++) {
//遍历tuples
Map map = new LinkedHashMap<>();//一条信息
for (Expression expression : qdc.getExpressions()) {
map.put(expression.toString().split(" as ")[1],//别名作为Key
tuples.get(i).get(expression));//获取结果
}
list.add(map);
}
PageListMapResult pageListMapResult = new PageListMapResult(list, pageNo, pageSize, jpaQuery.fetchCount());//分页封装
return pageListMapResult;
}
}
支持的对象
queryDslContext
package com.spark.bitrade.pagination;
import com.querydsl.core.types.EntityPath;
import com.querydsl.core.types.Expression;
import com.querydsl.core.types.OrderSpecifier;
import com.querydsl.core.types.Predicate;
import java.util.ArrayList;
import java.util.List;
/**
* @author rongyu
* @description
* @date 2018/3/7 13:10
*/
public class QueryDslContext {
private List expressions;
private List entityPaths;
private List predicates;
private List orderSpecifiers;
public QueryDslContext() {
this.expressions = new ArrayList<>();
this.entityPaths = new ArrayList<>();
this.predicates = new ArrayList<>();
this.orderSpecifiers = new ArrayList<>();
}
public List getExpressions() {
return expressions;
}
public void add(Expression expression) {
expressions.add(expression);
}
public void add(EntityPath entityPath) {
entityPaths.add(entityPath);
}
public void add(Predicate predicate) {
predicates.add(predicate);
}
public void add(OrderSpecifier orderSpecifier) {
orderSpecifiers.add(orderSpecifier);
}
public Expression[] expressionToArray() {
return expressions.toArray(new Expression[expressions.size()]);
}
public EntityPath[] entityPathToArray() {
return entityPaths.toArray(new EntityPath[entityPaths.size()]);
}
public Predicate[] predicatesToArray() {
return predicates.toArray(new Predicate[predicates.size()]);
}
public OrderSpecifier[] orderSpecifiersToArray() {
return orderSpecifiers.toArray(new OrderSpecifier[orderSpecifiers.size()]);
}
}
结果 对象
package com.spark.bitrade.pagination;
import lombok.AllArgsConstructor;
import lombok.Data;
import java.io.Serializable;
import java.util.List;
import java.util.Map;
/**
* @author rongyu
* @description
* @date 2018/2/28 15:48
*/
@AllArgsConstructor
@Data
public class PageListMapResult implements Serializable {
private List> list;
private int pageNo;
private int pageSize;
private Long totalNumber;
}
这是调用
=================================================自定义字段灵活条件分页查询方式==============================
@GetMapping("withdraw-records/page-query/test")
public MessageResult pageQueryTest(
@RequestParam(value = "pageNo", defaultValue = "1") Integer pageNo,
@RequestParam(value = "pageSize", defaultValue = "10") Integer pageSize,
@RequestParam(value = "status", required = false) WithdrawStatus status) {
QueryDslContext queryDslContext = new QueryDslContext();
//查询字段
queryDslContext.add(QWithdrawRecord.withdrawRecord.id.as("id"));
queryDslContext.add(QWithdrawRecord.withdrawRecord.fee.as("fee"));
queryDslContext.add(QWithdrawRecord.withdrawRecord.arrivedAmount.as("arrivedAmount"));
queryDslContext.add(QWithdrawRecord.withdrawRecord.transactionNumber.as("transactionNumber"));
queryDslContext.add(QWithdrawRecord.withdrawRecord.createTime.as("createTime"));
queryDslContext.add(QWithdrawRecord.withdrawRecord.address.as("address"));
queryDslContext.add(QWithdrawRecord.withdrawRecord.remark.as("remark"));
queryDslContext.add(QWithdrawRecord.withdrawRecord.status.as("status"));
//查询表
queryDslContext.add(QWithdrawRecord.withdrawRecord);
queryDslContext.add(QMember.member);
//查询条件
queryDslContext.add(QWithdrawRecord.withdrawRecord.memberId.eq(QMember.member.id));
if (status != null)
queryDslContext.add(withdrawRecord.status.eq(status));
//排序
queryDslContext.add(QWithdrawRecord.withdrawRecord.id.desc());
PageListMapResult pageListMapResult = withdrawRecordService.queryDslForPageListResultTest(queryDslContext, pageNo, pageSize);
return success(pageListMapResult);
}
=================================================灵活条件分页查询方式==============================
//条件
List predicateList = new ArrayList<>();
predicateList.add(QAdvertise.advertise.member.id.eq(member.getId()));
if (status != null) predicateList.add(QAdvertise.advertise.status.eq(status));
if (advertiseType != null) predicateList.add(QAdvertise.advertise.advertiseType.eq(advertiseType));
//排序
List orderSpecifierList = new ArrayList<>();
orderSpecifierList.add(QAdvertise.advertise.id.desc());
//查询
PageResult advertisePageResult = advertiseService.queryDsl(pageNo, pageSize, predicateList, QAdvertise.advertise, orderSpecifierList);