本篇内容介绍了“如何使用JPA进行CriteriaQuery进行查询”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
@Entity @Table(name = "report_workload") @JsonIgnoreProperties({"hibernateLazyInitializer", "handler"}) @JsonIdentityInfo(generator = JSOGGenerator.class) public class ReportWorkload { private int id; private Integer flowWorkItemApprId; private Integer busId; private Integer deptId; private Integer staffId; private Integer busiValueIndustryId; private Integer busiValueScaleId; private String taskName; private Integer count; private BigDecimal amount; private Date approvalTime; private String reportTime; private String deptName; private String staffName; @Id @Column(name = "id") @GeneratedValue(strategy = GenerationType.AUTO) public int getId() { return id; } public void setId(int id) { this.id = id; } @Basic @Column(name = "flow_work_item_appr_id") public Integer getFlowWorkItemApprId() { return flowWorkItemApprId; } public void setFlowWorkItemApprId(Integer flowWorkItemApprId) { this.flowWorkItemApprId = flowWorkItemApprId; } @Basic @Column(name = "bus_id") public Integer getBusId() { return busId; } public void setBusId(Integer busId) { this.busId = busId; } @Basic @Column(name = "dept_id") public Integer getDeptId() { return deptId; } public void setDeptId(Integer deptId) { this.deptId = deptId; } @Basic @Column(name = "staff_id") public Integer getStaffId() { return staffId; } public void setStaffId(Integer staffId) { this.staffId = staffId; } @Basic @Column(name = "busi_value_industry_id") public Integer getBusiValueIndustryId() { return busiValueIndustryId; } public void setBusiValueIndustryId(Integer busiValueIndustryId) { this.busiValueIndustryId = busiValueIndustryId; } @Basic @Column(name = "busi_value_scale_id") public Integer getBusiValueScaleId() { return busiValueScaleId; } public void setBusiValueScaleId(Integer busiValueScaleId) { this.busiValueScaleId = busiValueScaleId; } @Basic @Column(name = "task_name") public String getTaskName() { return taskName; } public void setTaskName(String taskName) { this.taskName = taskName; } @Basic @Column(name = "count") public Integer getCount() { return count; } public void setCount(Integer count) { this.count = count; } @Basic @Column(name = "amount") public BigDecimal getAmount() { return amount; } public void setAmount(BigDecimal amount) { this.amount = amount; } @Basic @Column(name = "approval_time") public Date getApprovalTime() { return approvalTime; } public void setApprovalTime(Date approvalTime) { this.approvalTime = approvalTime; } @Basic @Column(name = "report_time") public String getReportTime() { return reportTime; } public void setReportTime(String reportTime) { this.reportTime = reportTime; } @Transient public String getDeptName() { return deptName; } public void setDeptName(String deptName) { this.deptName = deptName; } @Transient public String getStaffName() { return staffName; } public void setStaffName(String staffName) { this.staffName = staffName; } @Override public boolean equals(Object o) { if (this == o) return true; if (!(o instanceof ReportWorkload)) return false; ReportWorkload that = (ReportWorkload) o; return id == that.id; } @Override public int hashCode() { return id; } public ReportWorkload(int id, Integer flowWorkItemApprId, Integer busId, Integer deptId, Integer staffId, Integer busiValueIndustryId, Integer busiValueScaleId, String taskName, Long count, BigDecimal amount, Date approvalTime, String reportTime) { this.id = id; this.flowWorkItemApprId = flowWorkItemApprId; this.busId = busId; this.deptId = deptId; this.staffId = staffId; this.busiValueIndustryId = busiValueIndustryId; this.busiValueScaleId = busiValueScaleId; this.taskName = taskName; this.count = Integer.parseInt(count+""); // this.count = count; this.amount = amount; this.approvalTime = approvalTime; this.reportTime = reportTime; } public ReportWorkload() { } }在进行聚合函数sum求和时，原来是int会自动提升为long,不做特殊处理就会报以下错误了：
org.hibernate.hql.internal.ast.DetailedSemanticException: Unable to locate appropriate constructor on class [com.changfa.frame.data.entity.report.Report Workload]. Expected arguments are: int, int, int, int, int, int, int, java.lang.String, long, java.math.BigDecimal, java.util.Date, java.lang.String at org.hibernate.hql.internal.ast.tree.ConstructorNode.resolveConstructor(ConstructorNode.java:182) at org.hibernate.hql.internal.ast.tree.ConstructorNode.prepare(ConstructorNode.java:144) at org.hibernate.hql.internal.ast.HqlSqlWalker.processConstructor(HqlSqlWalker.java:1092) at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectExpr(HqlSqlBaseWalker.java:2359)
会提示你查询数据库返回的类型和你的构造函数类型对应不上。
通过注解将EntityManager加载进来：
@PersistenceContext private EntityManager em;
public List<ReportWorkload> reportworkloadsearch(String reportTime, String deptId, String staffId, String typeId, String industryId) { List<ReportWorkload> reportWorkloadList = new ArrayList<>(); CriteriaBuilder criteriaBuilder = em.getCriteriaBuilder(); CriteriaQuery<ReportWorkload> cq = criteriaBuilder.createQuery(ReportWorkload.class); Root<ReportWorkload> rt = cq.from(ReportWorkload.class); cq.multiselect(rt.get("id"),rt.get("flowWorkItemApprId"), rt.get("busId"),rt.get("deptId"),rt.get("staffId"), rt.get("busiValueIndustryId"),rt.get("busiValueScaleId"), rt.get("taskName"),criteriaBuilder.sum(rt.get("count")), criteriaBuilder.sum(rt.get("amount")),rt.get("approvalTime"), rt.get("reportTime")); if(reportTime!=null&&reportTime!=""){ cq.where(criteriaBuilder.equal(rt.get("reportTime"), reportTime)); } if(deptId!=null&&deptId!=""){ cq.where(criteriaBuilder.equal(rt.get("deptId"), Integer.parseInt(deptId))); } if(staffId!=null&&staffId!=""){ cq.where(criteriaBuilder.equal(rt.get("staffId"), Integer.parseInt(staffId))); } if(typeId!=null&&typeId!=""){ cq.where(criteriaBuilder.equal(rt.get("typeId"), Integer.parseInt(typeId))); } if(industryId!=null&&industryId!=""){ cq.where(criteriaBuilder.equal(rt.get("industryId"), Integer.parseInt(industryId))); } cq.groupBy(rt.get("busId"),rt.get("deptId"),rt.get("taskName")); reportWorkloadList = em.createQuery(cq).getResultList(); return reportWorkloadList; }在进行cq.multiselect自定义返回字段时，必须在对应的pojo中给一个对应的返回字段构造函数
JPA动态查询（CriteriaQuery）封装的一段代码：
package com.platform.framework.dao.jpa; import java.io.Serializable; import java.util.ArrayList; import java.util.Collection; import java.util.Date; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import javax.persistence.EntityManager; import javax.persistence.criteria.CriteriaBuilder; import javax.persistence.criteria.CriteriaBuilder.In; import javax.persistence.criteria.CriteriaQuery; import javax.persistence.criteria.Order; import javax.persistence.criteria.Predicate; import javax.persistence.criteria.Root; import org.apache.log4j.Logger; /** * Query基类<br> * * @describe：封装JPA CriteriaBuilder查询条件 * @author：lry * @since：2014-05-23 */ @SuppressWarnings({ "unused", "unchecked", "rawtypes", "null", "hiding" }) public class Query implements Serializable { private static final long serialVersionUID = 5064932771068929342L; private static Logger log = Logger.getLogger(Query.class); private EntityManager entityManager; /** 要查询的模型对象 */ private Class clazz; /** 查询条件列表 */ private Root from; private List<Predicate> predicates; private CriteriaQuery criteriaQuery; private CriteriaBuilder criteriaBuilder; /** 排序方式列表 */ private List<Order> orders; /** 关联模式 */ private Map<String, Query> subQuery; private Map<String, Query> linkQuery; private String projection; /** 或条件 */ private List<Query> orQuery; private String groupBy; private Query() { } private Query(Class clazz, EntityManager entityManager) { this.clazz = clazz; this.entityManager = entityManager; this.criteriaBuilder = this.entityManager.getCriteriaBuilder(); this.criteriaQuery = criteriaBuilder.createQuery(this.clazz); this.from = criteriaQuery.from(this.clazz); this.predicates = new ArrayList(); this.orders = new ArrayList(); } /** 通过类创建查询条件 */ public static Query forClass(Class clazz, EntityManager entityManager) { return new Query(clazz, entityManager); } /** 增加子查询 */ private void addSubQuery(String propertyName, Query query) { if (this.subQuery == null) this.subQuery = new HashMap(); if (query.projection == null) throw new RuntimeException("子查询字段未设置"); this.subQuery.put(propertyName, query); } private void addSubQuery(Query query) { addSubQuery(query.projection, query); } /** 增关联查询 */ public void addLinkQuery(String propertyName, Query query) { if (this.linkQuery == null) this.linkQuery = new HashMap(); this.linkQuery.put(propertyName, query); } /** 相等 */ public void eq(String propertyName, Object value) { if (isNullOrEmpty(value)) return; this.predicates.add(criteriaBuilder.equal(from.get(propertyName), value)); } private boolean isNullOrEmpty(Object value) { if (value instanceof String) { return value == null || "".equals(value); } return value == null; } public void or(List<String> propertyName, Object value) { if (isNullOrEmpty(value)) return; if ((propertyName == null) || (propertyName.size() == 0)) return; Predicate predicate = criteriaBuilder.or(criteriaBuilder.equal(from.get(propertyName.get(0)), value)); for (int i = 1; i < propertyName.size(); ++i) predicate = criteriaBuilder.or(predicate, criteriaBuilder.equal(from.get(propertyName.get(i)), value)); this.predicates.add(predicate); } public void orLike(List<String> propertyName, String value) { if (isNullOrEmpty(value) || (propertyName.size() == 0)) return; if (value.indexOf("%") < 0) value = "%" + value + "%"; Predicate predicate = criteriaBuilder.or(criteriaBuilder.like(from.get(propertyName.get(0)), value.toString())); for (int i = 1; i < propertyName.size(); ++i) predicate = criteriaBuilder.or(predicate, criteriaBuilder.like(from.get(propertyName.get(i)), value)); this.predicates.add(predicate); } /** 空 */ public void isNull(String propertyName) { this.predicates.add(criteriaBuilder.isNull(from.get(propertyName))); } /** 非空 */ public void isNotNull(String propertyName) { this.predicates.add(criteriaBuilder.isNotNull(from.get(propertyName))); } /** 不相等 */ public void notEq(String propertyName, Object value) { if (isNullOrEmpty(value)) { return; } this.predicates.add(criteriaBuilder.notEqual(from.get(propertyName), value)); } /** * not in * * @param propertyName * 属性名称 * @param value * 值集合 */ public void notIn(String propertyName, Collection value) { if ((value == null) || (value.size() == 0)) { return; } Iterator iterator = value.iterator(); In in = criteriaBuilder.in(from.get(propertyName)); while (iterator.hasNext()) { in.value(iterator.next()); } this.predicates.add(criteriaBuilder.not(in)); } /** * 模糊匹配 * * @param propertyName * 属性名称 * @param value * 属性值 */ public void like(String propertyName, String value) { if (isNullOrEmpty(value)) return; if (value.indexOf("%") < 0) value = "%" + value + "%"; this.predicates.add(criteriaBuilder.like(from.get(propertyName), value)); } /** * 时间区间查询 * * @param propertyName * 属性名称 * @param lo * 属性起始值 * @param go * 属性结束值 */ public void between(String propertyName, Date lo, Date go) { if (!isNullOrEmpty(lo) && !isNullOrEmpty(go)) { this.predicates.add(criteriaBuilder.between(from.get(propertyName), lo, go)); } // if (!isNullOrEmpty(lo) && !isNullOrEmpty(go)) { // this.predicates.add(criteriaBuilder.lessThan(from.get(propertyName), // new DateTime(lo).toString())); // } // if (!isNullOrEmpty(go)) { // this.predicates.add(criteriaBuilder.greaterThan(from.get(propertyName), // new DateTime(go).toString())); // } } public void between(String propertyName, Number lo, Number go) { if (!(isNullOrEmpty(lo))) ge(propertyName, lo); if (!(isNullOrEmpty(go))) le(propertyName, go); } /** * 小于等于 * * @param propertyName * 属性名称 * @param value * 属性值 */ public void le(String propertyName, Number value) { if (isNullOrEmpty(value)) { return; } this.predicates.add(criteriaBuilder.le(from.get(propertyName), value)); } /** * 小于 * * @param propertyName * 属性名称 * @param value * 属性值 */ public void lt(String propertyName, Number value) { if (isNullOrEmpty(value)) { return; } this.predicates.add(criteriaBuilder.lt(from.get(propertyName), value)); } /** * 大于等于 * * @param propertyName * 属性名称 * @param value * 属性值 */ public void ge(String propertyName, Number value) { if (isNullOrEmpty(value)) { return; } this.predicates.add(criteriaBuilder.ge(from.get(propertyName), value)); } /** * 大于 * * @param propertyName * 属性名称 * @param value * 属性值 */ public void gt(String propertyName, Number value) { if (isNullOrEmpty(value)) { return; } this.predicates.add(criteriaBuilder.gt(from.get(propertyName), value)); } /** * in * * @param propertyName * 属性名称 * @param value * 值集合 */ public void in(String propertyName, Collection value) { if ((value == null) || (value.size() == 0)) { return; } Iterator iterator = value.iterator(); In in = criteriaBuilder.in(from.get(propertyName)); while (iterator.hasNext()) { in.value(iterator.next()); } this.predicates.add(in); } /** 直接添加JPA内部的查询条件,用于应付一些复杂查询的情况,例如或 */ public void addCriterions(Predicate predicate) { this.predicates.add(predicate); } /** * 创建查询条件 * * @return JPA离线查询 */ public CriteriaQuery newCriteriaQuery() { criteriaQuery.where(predicates.toArray(new Predicate[0])); if (!isNullOrEmpty(groupBy)) { criteriaQuery.groupBy(from.get(groupBy)); } if (this.orders != null) { criteriaQuery.orderBy(orders); } addLinkCondition(this); return criteriaQuery; } private void addLinkCondition(Query query) { Map subQuery = query.linkQuery; if (subQuery == null) return; for (Iterator queryIterator = subQuery.keySet().iterator(); queryIterator.hasNext();) { String key = (String) queryIterator.next(); Query sub = (Query) subQuery.get(key); from.join(key); criteriaQuery.where(sub.predicates.toArray(new Predicate[0])); addLinkCondition(sub); } } public void addOrder(String propertyName, String order) { if (order == null || propertyName == null) return; if (this.orders == null) this.orders = new ArrayList(); if (order.equalsIgnoreCase("asc")) this.orders.add(criteriaBuilder.asc(from.get(propertyName))); else if (order.equalsIgnoreCase("desc")) this.orders.add(criteriaBuilder.desc(from.get(propertyName))); } public void setOrder(String propertyName, String order) { this.orders = null; addOrder(propertyName, order); } public Class getModleClass() { return this.clazz; } public String getProjection() { return this.projection; } public void setProjection(String projection) { this.projection = projection; } public Class getClazz() { return this.clazz; } public List<Order> getOrders() { return orders; } public void setOrders(List<Order> orders) { this.orders = orders; } public EntityManager getEntityManager() { return this.entityManager; } public void setEntityManager(EntityManager em) { this.entityManager = em; } public Root getFrom() { return from; } public List<Predicate> getPredicates() { return predicates; } public void setPredicates(List<Predicate> predicates) { this.predicates = predicates; } public CriteriaQuery getCriteriaQuery() { return criteriaQuery; } public CriteriaBuilder getCriteriaBuilder() { return criteriaBuilder; } public void setFetchModes(List<String> fetchField, List<String> fetchMode) { } public String getGroupBy() { return groupBy; } public void setGroupBy(String groupBy) { this.groupBy = groupBy; } }<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:util="http://www.springframework.org/schema/util" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd"> <!-- JPA Entity Manager Factory --> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" p:packagesToScan="com.**.model" p:dataSource-ref="dataSource" p:jpaVendorAdapter-ref="hibernateVendor" p:jpaPropertyMap-ref="jpaPropertyMap"/> <util:map id="jpaPropertyMap"> <entry key="hibernate.hbm2ddl.auto" value="update" /><!-- create,update,none --> <entry key="hibernate.format_sql" value="false" /> <entry key="hibernate.show_sql" value="false" /> <entry key="hibernate.current_session_context_class" value="org.hibernate.context.internal.ThreadLocalSessionContext"/> <entry key="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" /> <!-- To enable Hibernate's second level cache and query cache settings --> <entry key="hibernate.max_fetch_depth" value="4" /> <entry key="hibernate.cache.use_second_level_cache" value="true" /> <entry key="hibernate.cache.use_query_cache" value="true" /> <!-- <entry key="hibernate.cache.region.factory_class" value="org.hibernate.cache.ehcache.EhCacheRegionFactory" /> --> <entry key="hibernate.cache.region.factory_class" value="org.hibernate.cache.SingletonEhCacheRegionFactory" /> </util:map> <bean id="hibernateVendor" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" p:database="MYSQL" p:showSql="true" p:generateDdl="true" p:databasePlatform="org.hibernate.dialect.MySQLDialect" /> <bean id="transactionHandler" class="com.platform.framework.dao.jpa.TransactionHandler" > <property name="txmethod"> <list> <value>insert</value> <value>update</value> <value>delete</value> </list> </property> <property name="entityManagerFactory" ref="entityManagerFactory"/> </bean> <aop:config> <aop:aspect id="tran" ref="transactionHandler"> <aop:pointcut id="tranMethod" expression=" execution(* com.*.dao.*.*(..))|| execution(* com.*.service.impl.*.*(..))|| execution(* com.*.*.dao.*.*(..))|| execution(* com.*.*.service.impl.*.*(..))|| execution(* com.*.*.*.dao.*.*(..))|| execution(* com.*.*.*.service.impl.*.*(..))|| execution(* com.*.*.*.*.dao.*.*(..))|| execution(* com.*.*.*.*.service.impl.*.*(..))|| execution(* com.*.*.*.*.*.dao.*.*(..))|| execution(* com.*.*.*.*.*.service.impl.*.*(..))|| execution(* com.*.*.*.*.*.*.dao.*.*(..))|| execution(* com.*.*.*.*.*.*.service.impl.*.*(..))|| execution(* com.platform.framework.dao.jpa.BaseDaoImpl.*(..))"/> <aop:around method="exec" pointcut-ref="tranMethod" /> </aop:aspect> </aop:config> <bean id="baseDao" class="com.platform.framework.dao.jpa.BaseDaoImpl"> <property name="emf" ref="entityManagerFactory"/> </bean> </beans>
package com.platform.framework.dao.jpa; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.EntityTransaction; import org.apache.log4j.Logger; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.Signature; /** * @describe JPA事务管理 * @author lry * @since：2014-05-23 * */ public class TransactionHandler { private static final Logger log = Logger .getLogger(TransactionHandler.class); private String[] txmethod;// 配置事务的传播特性方法 private EntityManagerFactory entityManagerFactory;// JPA工厂 public Object exec(ProceedingJoinPoint point) throws Throwable { Signature signature = point.getSignature(); log.debug(point.getTarget().getClass().getName() + "." + signature.getName() + "()"); Boolean isTransaction = false; for (String method : txmethod) { if (signature.getName().startsWith(method)) {// 以method开头的方法打开事务 isTransaction = true; break; } } // JPA->Hibernate if (point.getTarget() instanceof EntityManagerFactoryProxy) { // 获得被代理对象 EntityManagerFactoryProxy emfp = (EntityManagerFactoryProxy) point .getTarget(); EntityManager em = emfp.getEntityManager(); if (em != null) {// 如果对象已经有em了就不管 return point.proceed(); } else { em = entityManagerFactory.createEntityManager(); } log.debug("JPA->Hibernate open connection..."); if (isTransaction) { EntityTransaction t = null; try { // 打开连接并开启事务 log.debug("JPA->Hibernate begin transaction..."); t = em.getTransaction(); if (!t.isActive()) t.begin(); emfp.setEntityManager(em); Object obj = point.proceed(); // 提交事务 log.debug("JPA->Hibernate commit..."); t.commit(); return obj; } catch (Exception e) { if (t != null) { log.debug("JPA->Hibernate error...,rollback..." + e.getMessage()); t.rollback(); } e.printStackTrace(); throw e; } finally { if (em != null && em.isOpen()) {// 关闭连接 em.close(); log.debug("JPA->Hibernate close connection..."); } emfp.setEntityManager(null); } } else { try { emfp.setEntityManager(em); return point.proceed(); } catch (Exception e) { log.debug("JPA->Hibernate error..." + e.getMessage()); e.printStackTrace(); throw e; } finally { if (em != null && em.isOpen()) {// 关闭连接 em.close(); log.debug("JPA->Hibernate close connection..."); } emfp.setEntityManager(null); } } } else { return point.proceed(); } } public String[] getTxmethod() { return txmethod; } public void setTxmethod(String[] txmethod) { this.txmethod = txmethod; } public void setEntityManagerFactory( EntityManagerFactory entityManagerFactory) { this.entityManagerFactory = entityManagerFactory; } }package com.platform.framework.dao.jpa; import java.util.Collection; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; /** * EntityManager管理器 * * @author：yangjian1004 * @since：2011-11-30 16:14:24 AM */ public class EntityManagerFactoryProxy { private static ThreadLocal<EntityManager> emThreadLocal = new ThreadLocal<EntityManager>(); private static EntityManagerFactory emf; public void setEmf(EntityManagerFactory emf) { EntityManagerFactoryProxy.emf = emf; } public static EntityManagerFactory getEmf() { return emf; } public EntityManager getEntityManager() { return emThreadLocal.get(); } public void setEntityManager(EntityManager em) { emThreadLocal.set(em); } /** * 创建查询条件 * * @param name * 字段名称 * @param values * 字段值 */ public String createInCondition(String name, Collection<String> values) { if (values == null || values.size() == 0) { return "1<>1"; } StringBuffer sb = new StringBuffer(); sb.append(name + " in("); for (String id : values) { sb.append("'" + id + "',"); } String hsqlCondition = sb.substring(0, sb.length() - 1) + ")"; return hsqlCondition; } }package com.platform.framework.dao.jpa; import java.io.Serializable; import java.util.ArrayList; import java.util.List; /** * Page基类<br> * * @describe：分页 */ public class Page<T> implements Serializable { private static final long serialVersionUID = 665620345605746930L; /** 总条数 */ private int count; /** 页码 */ private int pageNo; /** 每页显示多少条 */ private int rowsPerPage; /** 总页数 */ private int totalPageCount; /** 起始条数 */ private int firstRow; /** 结束条数 */ private int lastRow; /** 查询结果集合形式的结果 */ private List<T> result; /** 查询结果对象形式的结果 */ public Object obj; public Integer code; // 返回码 private boolean success = true; private String message; public Page() { } public Page(List<T> list) { this(list.size(), 1, list.size(), list); } public Page(int count, int pageNo, int rowsPerPage, List<T> result) { if (rowsPerPage < 1) { rowsPerPage = 1; } this.count = count; this.pageNo = pageNo; this.result = result; this.rowsPerPage = rowsPerPage; if (this.result == null) this.result = new ArrayList<T>(); totalPageCount = count / rowsPerPage; if (count - (count / rowsPerPage) * rowsPerPage > 0) totalPageCount++; if (count == 0) { totalPageCount = 0; pageNo = 0; } firstRow = (pageNo - 1) * rowsPerPage + 1; if (count == 0) { firstRow = 0; } lastRow = (pageNo) * rowsPerPage; if (lastRow > count) { lastRow = count; } } /** 返回每页的条数 */ public int getCount() { return count; } public List<T> getResult() { return result; } public int getPageNo() { return pageNo; } /** 返回每页的条数 */ public int getRowsPerPage() { return rowsPerPage; } /** 返回总的页数 */ public int getTotalPageCount() { return totalPageCount; } public void setPageNo(int pageNo) { this.pageNo = pageNo; } public void setRowsPerPage(int rowsPerPage) { this.rowsPerPage = rowsPerPage; } public int getFirstRow() { return firstRow; } public int getLastRow() { return lastRow; } public void setFirstRow(int firstRow) { this.firstRow = firstRow; } public void setLastRow(int lastRow) { this.lastRow = lastRow; } public void setCount(int count) { this.count = count; } public void setTotalPageCount(int totalPageCount) { this.totalPageCount = totalPageCount; } public void setResult(List<T> result) { this.result = result; } public Object getObj() { return obj; } public void setObj(Object obj) { this.obj = obj; } public boolean isSuccess() { return success; } public void setSuccess(boolean success) { this.success = success; } public String getMessage() { return message; } public void setMessage(String message) { this.message = message; } /** * 计算起始条数 */ public static int calc(int pageNo, int rowsPerPage, int count) { if (pageNo <= 0) pageNo = 1; if (rowsPerPage <= 0) rowsPerPage = 10; // 当把最后一页数据删除以后,页码会停留在最后一个上必须减一 int totalPageCount = count / rowsPerPage; if (pageNo > totalPageCount && (count % rowsPerPage == 0)) { pageNo = totalPageCount; } if (pageNo - totalPageCount > 2) { pageNo = totalPageCount + 1; } int firstRow = (pageNo - 1) * rowsPerPage; if (firstRow < 0) { firstRow = 0; } return firstRow; } }package com.platform.framework.dao.jpa; import java.io.Serializable; import java.util.List; import javax.persistence.EntityManager; import javax.persistence.criteria.CriteriaQuery; import javax.persistence.criteria.Predicate; import javax.persistence.criteria.Selection; import javax.persistence.metamodel.EntityType; import org.apache.log4j.Logger; import com.google.common.base.Strings; /** * IBaseDao接口实现了BaseDaoImpl类<br> */ @SuppressWarnings({ "unchecked", "rawtypes" }) public class BaseDaoImpl<T> extends EntityManagerFactoryProxy implements IBaseDao { private static Logger log = Logger.getLogger(BaseDaoImpl.class); /** 每次批量操作数 */ private int batchSize = 50; /** 设置每次操作数 */ public void setBatchSize(int batchSize) { this.batchSize = batchSize; } public <E> E get(Class clazz, Serializable id) { return (E) getEntityManager().find(clazz, id); } /** * 插入记录 * * @param entity * 要插入的记录 */ public void insert(Object entity) { if (entity instanceof List) { insertList((List) entity); return; } else if (entity instanceof Object[]) { return; } try { getEntityManager().persist(entity); } catch (Exception e) { e.printStackTrace(); } } /** * 批量增加 * * @param list * 要新增的数据 */ public void insertList(List list) { EntityManager entityManager = getEntityManager(); if (list == null || list.size() == 0) { return; } int i = 0; for (Object o : list) { insert(o); if (i % batchSize == 0) { entityManager.flush(); } i++; } log.debug(list.get(0).getClass() + "批量增加数据" + i + "条"); } /** * 更新记录 * * @param entity * 要更新的记录 */ public void update(Object entity) { if (entity instanceof List) { this.updateList((List) entity); return; } getEntityManager().merge(entity); } /** 更新list */ public void updateList(List list) { for (Object entity : list) { this.update(entity); } } /** * 删除记录 * * @param entity * 要删除的记录 */ public void delete(Object entity) { if (entity instanceof List) { List list = (List) entity; for (Object o : list) { getEntityManager().remove(o); } } else { getEntityManager().remove(entity); } } public <E extends Serializable> List<E> query(String jpql) { return getEntityManager().createQuery(jpql).getResultList(); } public Integer updateJpql(String jpql) { return getEntityManager().createQuery(jpql).executeUpdate(); } public Integer updateSql(String sql) { return getEntityManager().createNativeQuery(sql).executeUpdate(); } public <E extends Serializable> List<E> queryBySql(String sql) { return getEntityManager().createNativeQuery(sql).getResultList(); } /** * 查询记录 * * @param clazz * 要查询的实体类 * @param hqlCondition * 查询条件 */ public <E extends Serializable> List<E> query(Class clazz, String hqlCondition) { return getEntityManager().createQuery("select t from " + clazz.getName() + " as t where " + hqlCondition) .getResultList(); } public void delete(Class entity, String jpqlCondition) { if (Strings.isNullOrEmpty(jpqlCondition)) { jpqlCondition = "1=1"; } int no = updateJpql("delete " + entity.getName() + " where " + jpqlCondition); log.debug(entity.getName() + "删除" + no + "条数据"); } /** * 根据ids删除数据 * * @param entity * 删除实体类 * @param ids * 删除条件 */ public void delete(Class entity, List ids) { String idName = getIdName(entity, getEntityManager()); StringBuffer sb = new StringBuffer(); sb.append(idName + " in("); for (int i = 0; i < ids.size(); i++) { sb.append("'" + ids.get(i) + "',"); } String jpqlCondition = sb.substring(0, sb.length() - 1) + ")"; delete(entity, jpqlCondition); } public <E extends Serializable> List<E> query(String jpql, int firstResult, int maxResults) { List result = getEntityManager().createQuery(jpql).setFirstResult(firstResult).setMaxResults(maxResults) .getResultList(); return result; } public <E extends Serializable> List<E> queryBySql(String sql, int firstResult, int maxResults) { return getEntityManager().createNativeQuery(sql).setFirstResult(firstResult).setMaxResults(maxResults) .getResultList(); } public <E extends Serializable> List<E> queryAll(Class clazz) { CriteriaQuery criteriaQuery = getEntityManager().getCriteriaBuilder().createQuery(clazz); criteriaQuery.from(clazz); return getEntityManager().createQuery(criteriaQuery).getResultList(); } public Page queryPageByJpql(String jpql, int pageNo, int rowsPerPage) { if (pageNo <= 0) pageNo = 1; if (rowsPerPage <= 0) rowsPerPage = 7; log.debug("-----开始查询,页码:" + pageNo + ",每页显示:" + rowsPerPage + "----"); String countJpql = "select count(*) from (" + jpql + ")"; int count = getCount(countJpql).intValue(); // 当把最后一页数据删除以后,页码会停留在最后一个上必须减一 int totalPageCount = count / rowsPerPage; if (pageNo > totalPageCount && (count % rowsPerPage == 0)) { pageNo = totalPageCount; } if (pageNo - totalPageCount > 2) { pageNo = totalPageCount + 1; } int firstResult = (pageNo - 1) * rowsPerPage; if (firstResult < 0) { firstResult = 0; } List result = getEntityManager().createQuery(jpql).setFirstResult(firstResult).setMaxResults(rowsPerPage) .getResultList(); return new Page(count, pageNo, rowsPerPage, result); } public Long getCount(String jpql) { return (Long) getEntityManager().createQuery(jpql).getResultList().get(0); } /*** * * @Method updateJpql * @Description 根据传入的带有占位符的sql语句, 做增删改操作 例如 * updateJpql("update user t set t.name=? where t.id=?" * ,{[zhongxiang],[23]}) * @Author 钟翔/zhongxiang * @Date 2012-8-9 下午3:38:35 * @param jpql * 占位符式的sql * @param paramList * list里面装有[zhongxiang , 23] */ public void updateJpql(String jpql, List paramList) { javax.persistence.Query query = getEntityManager().createQuery(jpql); for (int i = 0; i < paramList.size(); i++) { query.setParameter(i + 1, paramList.get(i)); } query.executeUpdate(); } /** * 统计记录 * * @param query * 统计条件 */ public Long getCount(Query query) { Selection selection = query.getCriteriaQuery().getSelection(); query.getCriteriaQuery().select(query.getCriteriaBuilder().count(query.getFrom())); Long count = (Long) getEntityManager().createQuery(query.newCriteriaQuery()).getResultList().get(0); query.getCriteriaQuery().select(selection); return count; } /** * 分页查询 * * @param query * 查询条件 * @param pageNo * 页号 * @param rowsPerPage * 每页显示条数 */ public Page queryPage(Query query, int pageNo, int rowsPerPage) { if (pageNo <= 0) pageNo = 1; if (rowsPerPage <= 0) rowsPerPage = 7; log.debug(query.getClazz() + "-----开始查询,页码:" + pageNo + ",每页显示:" + rowsPerPage + "----"); log.debug("查询条件:"); for (Predicate cri : query.getPredicates()) log.debug(cri); int count = getCount(query).intValue(); // 当把最后一页数据删除以后,页码会停留在最后一个上必须减一 int totalPageCount = count / rowsPerPage; if (pageNo > totalPageCount && (count % rowsPerPage == 0)) { pageNo = totalPageCount; } if (pageNo - totalPageCount > 2) { pageNo = totalPageCount + 1; } int firstResult = (pageNo - 1) * rowsPerPage; if (firstResult < 0) { firstResult = 0; } List result = getEntityManager().createQuery(query.newCriteriaQuery()).setFirstResult(firstResult) .setMaxResults(rowsPerPage).getResultList(); return new Page(count, pageNo, rowsPerPage, result); } /** * 根据query查找记录 * * @param query * 查询条件 * @param firstResult * 起始行 * @param maxResults * 结束行 */ public <E extends Serializable> List<E> query(Query query, int firstResult, int maxResults) { List result = getEntityManager().createQuery(query.newCriteriaQuery()).setFirstResult(firstResult) .setMaxResults(maxResults).getResultList(); return result; } /** * 根据query查找记录 * * @param query * 查询条件 */ public <E extends Serializable> List<E> query(Query query) { return getEntityManager().createQuery(query.newCriteriaQuery()).getResultList(); } /** * 获得主键名称 * * @param clazz * 操作是实体对象 * @param EntityManager * jpa的entityManager工厂 * @return 初建名称 * */ public static String getIdName(Class clazz, EntityManager entityManager) { EntityType entityType = entityManager.getMetamodel().entity(clazz); return entityType.getId(entityType.getIdType().getJavaType()).getName(); } }package com.platform.framework.dao.jpa; import java.io.Serializable; import java.util.List; import javax.persistence.EntityManager; /** * IBaseDao基类<br> * * @describe：系统基础JPA Dao接口 */ @SuppressWarnings({ "rawtypes" }) public interface IBaseDao { public EntityManager getEntityManager(); public <E> E get(Class clazz, Serializable id); /** * 插入记录 * * @param entity * 要插入的记录 */ public void insert(Object entity); /** * 更新记录 * * @param entity * 要更新的记录 */ public void update(Object entity); /** 更新list */ public void updateList(List list); /** * 删除记录 * * @param entity * 要删除的记录 */ public void delete(Object entity); /** * 删除记录 * * @param entity * 要删除的记录 */ public void delete(Class entity, List ids); /** * 删除记录 * * @param entity * 要删除的记录 */ public void delete(Class entity, String jpqlCondition); /** * 统计记录 * * @param query * 统计条件 */ public Long getCount(Query query); public Long getCount(String jpql); /** * 分页查询 * * @param query * 查询条件 * @param pageNo * 页号 * @param rowsPerPage * 每页显示条数 */ public Page queryPage(Query query, int pageNo, int rowsPerPage); /** * 根据query查找记录 * * @param query * 查询条件 * @param firstResult * 起始行 * @param maxResults * 结束行 */ public <E extends Serializable> List<E> query(Query query, int firstResult, int maxResults); /** * 根据query查找记录 * * @param query * 查询条件 */ public <E extends Serializable> List<E> query(Query query); /** * 执行更新操作的jpql语句 * * @param jpql * 要执行的jpql语句 */ public <E extends Serializable> List<E> query(String jpql); public <E extends Serializable> List<E> queryAll(Class clazz); public <E extends Serializable> List<E> query(String jpql, int firstResult, int maxResults); /** * 执行查询操作的sql语句 * * @param sql * 要执行的sql语句 */ public <E extends Serializable> List<E> queryBySql(String sql); public <E extends Serializable> List<E> queryBySql(String sql, int firstResult, int maxResults); /** * 查询记录 * * @param clazz * 要查询的实体类 * @param hqlCondition * 查询条件 */ public <E extends Serializable> List<E> query(Class clazz, String hqlCondition); /** * 执行更新操作的sql语句 * * @param sql * 要执行的sql语句 */ public Integer updateSql(String sql); public Integer updateJpql(String jpql); public Page queryPageByJpql(String hql, int pageNo, int rowsPerPage); public void updateJpql(String jpql, List paramList); }“如何使用JPA进行CriteriaQuery进行查询”的内容就介绍到这里了，感谢大家的阅读。如果想了解更多行业相关的知识可以关注亿速云网站，小编将为大家输出更多高质量的实用文章！
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