如何使用JPA进行CriteriaQuery进行查询

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！

使用JPA CriteriaQuery查询的注意事项

1.pojo类

@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。

service层

通过注解将EntityManager加载进来：

 @PersistenceContext private EntityManager em;

查询方法

 public List reportworkloadsearch(String reportTime, String deptId, String staffId, String typeId, String industryId) {         List reportWorkloadList = new ArrayList<>();        CriteriaBuilder criteriaBuilder = em.getCriteriaBuilder();        CriteriaQuery cq = criteriaBuilder.createQuery(ReportWorkload.class);        Root 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

封装JPA动态查询（CriteriaQuery）

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
 *  * @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 predicates;         private CriteriaQuery criteriaQuery;         private CriteriaBuilder criteriaBuilder;         /** 排序方式列表 */        private List orders;         /** 关联模式 */        private Map subQuery;         private Map linkQuery;         private String projection;         /** 或条件 */        private List 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 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 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 getOrders() {                return orders;        }         public void setOrders(List 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 getPredicates() {                return predicates;        }         public void setPredicates(List predicates) {                this.predicates = predicates;        }         public CriteriaQuery getCriteriaQuery() {                return criteriaQuery;        }         public CriteriaBuilder getCriteriaBuilder() {                return criteriaBuilder;        }         public void setFetchModes(List fetchField, List fetchMode) {         }         public String getGroupBy() {                return groupBy;        }         public void setGroupBy(String groupBy) {                this.groupBy = groupBy;        } }

                                                                                                                                                                                                                                                                                                                               insert                                update                                delete                                                                                                                                                                                                        

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;        } }

EntityManager管理器，通过spring管理

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 emThreadLocal = new ThreadLocal();        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 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;        }}

Page分页和结果封装类

package com.platform.framework.dao.jpa; import java.io.Serializable;import java.util.ArrayList;import java.util.List; /** * Page基类
 *  * @describe：分页 */public class Page 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 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 list) {                this(list.size(), 1, list.size(), list);        }         public Page(int count, int pageNo, int rowsPerPage, List 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();                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 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 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;        } }

IBaseDao接口实现了BaseDaoImpl

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
 */@SuppressWarnings({ "unchecked", "rawtypes" })public class BaseDaoImpl 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 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  List 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  List 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  List 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  List query(String jpql, int firstResult, int maxResults) {                List result = getEntityManager().createQuery(jpql).setFirstResult(firstResult).setMaxResults(maxResults)                                .getResultList();                return result;        }         public  List queryBySql(String sql, int firstResult, int maxResults) {                return getEntityManager().createNativeQuery(sql).setFirstResult(firstResult).setMaxResults(maxResults)                                .getResultList();        }         public  List 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  List 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  List 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();        }}

IBaseDao接口

package com.platform.framework.dao.jpa; import java.io.Serializable;import java.util.List; import javax.persistence.EntityManager; /** * IBaseDao基类
 *  * @describe：系统基础JPA Dao接口 */@SuppressWarnings({ "rawtypes" })public interface IBaseDao {                public EntityManager getEntityManager();         public  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  List query(Query query, int firstResult, int maxResults);         /**         * 根据query查找记录         *          * @param query         *            查询条件         */        public  List query(Query query);         /**         * 执行更新操作的jpql语句         *          * @param jpql         *            要执行的jpql语句         */        public  List query(String jpql);         public  List queryAll(Class clazz);         public  List 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  List queryBySql(String sql);         public  List 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  List 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); }

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