使用JPA进行CriteriaQuery进行查询的注意事项

目录

• 使用JPA CriteriaQuery查询的注意事项
• 1.pojo类
• service层
• 查询方法
• 封装JPA动态查询（CriteriaQuery）
• EntityManager管理器，通过spring管理
• Page分页和结果封装类
• IBaseDao接口实现了BaseDaoImpl
• IBaseDao接口

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); 
}

以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。