这篇文章将为大家详细讲解有关JPA使用criteria简单查询工具类的方式是什么，文章内容质量较高，因此小编分享给大家做个参考，希望大家阅读完这篇文章后对相关知识有一定的了解。
以前用jpa写了一个条件筛选的查询数据如下，才知道那么渣渣，就是一个表，根据前端来筛选数据，写的如下
首先就是判断前端传来的参数就写了那么多，现在才发现是渣渣中的渣渣，而且还费时，用criteria很快就搞定
首先创建类并实现Specification<T>接口
import java.util.ArrayList;import java.util.List; import javax.persistence.criteria.CriteriaBuilder;import javax.persistence.criteria.CriteriaQuery;import javax.persistence.criteria.Predicate;import javax.persistence.criteria.Root; import org.springframework.data.jpa.domain.Specification; public class ExpandCriteria<T> implements Specification<T>{ private List<ExpandCriterion> criterions = new ArrayList<ExpandCriterion>(); public Predicate toPredicate(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder builder) { if (!criterions.isEmpty()) { List<Predicate> predicates = new ArrayList<Predicate>(); for(ExpandCriterion c : criterions){ predicates.add(c.toPredicate(root, query,builder)); } // 将所有条件用 and 联合起来 if (predicates.size() > 0) { return builder.and(predicates.toArray(new Predicate[predicates.size()])); } } return builder.conjunction(); } public void add(ExpandCriterion criterion){ if(criterion!=null){ criterions.add(criterion); } } public static void main(String[] args) { //使用示例Demo// Criteria<Entity> c = new Criteria<Entity>();// c.add(Restrictions.like("code", searchParam.getCode(), true)); // c.add(Restrictions.eq("level", searchParam.getLevel(), false)); // c.add(Restrictions.eq("mainStatus", searchParam.getMainStatus(), true)); // c.add(Restrictions.eq("flowStatus", searchParam.getFlowStatus(), true)); // c.add(Restrictions.eq("createUser.userName", searchParam.getCreateUser(), true)); // c.add(Restrictions.lte("submitTime", searchParam.getStartSubmitTime(), true)); // c.add(Restrictions.gte("submitTime", searchParam.getEndSubmitTime(), true)); // c.add(Restrictions.eq("needFollow", searchParam.getIsfollow(), true)); // c.add(Restrictions.ne("flowStatus", searchParam.getMainStatus() true)); // c.add(Restrictions.in("solveTeam.code",teamCodes, true)); // repository.findAll(c); }}新建ExpandCriterion接口
import javax.persistence.criteria.CriteriaBuilder;import javax.persistence.criteria.CriteriaQuery;import javax.persistence.criteria.Predicate;import javax.persistence.criteria.Root; public interface ExpandCriterion { public enum Operator { EQ, NE, LIKE, GT, LT, GTE, LTE, AND, OR } public Predicate toPredicate(Root<?> root, CriteriaQuery<?> query, CriteriaBuilder builder); }新建Restrictions.java
import java.util.Collection; import org.springframework.util.StringUtils; import com.sll.iot.dao.base.criteria.ExpandCriterion.Operator; public class Restrictions { public static SimpleExpression eq(String fieldName, Object value, boolean ignoreNull) { if(StringUtils.isEmpty(value))return null; return new SimpleExpression (fieldName, value, Operator.EQ); } public static SimpleExpression ne(String fieldName, Object value, boolean ignoreNull) { if(StringUtils.isEmpty(value))return null; return new SimpleExpression (fieldName, value, Operator.NE); } public static SimpleExpression like(String fieldName, String value, boolean ignoreNull) { if(StringUtils.isEmpty(value))return null; return new SimpleExpression (fieldName, value, Operator.LIKE); } public static SimpleExpression gt(String fieldName, Object value, boolean ignoreNull) { if(StringUtils.isEmpty(value))return null; return new SimpleExpression (fieldName, value, Operator.GT); } public static SimpleExpression lt(String fieldName, Object value, boolean ignoreNull) { if(StringUtils.isEmpty(value))return null; return new SimpleExpression (fieldName, value, Operator.LT); } public static SimpleExpression lte(String fieldName, Object value, boolean ignoreNull) { if(StringUtils.isEmpty(value))return null; return new SimpleExpression (fieldName, value, Operator.GTE); } public static SimpleExpression gte(String fieldName, Object value, boolean ignoreNull) { if(StringUtils.isEmpty(value))return null; return new SimpleExpression (fieldName, value, Operator.LTE); } public static LogicalExpression and(ExpandCriterion... criterions){ return new LogicalExpression(criterions, Operator.AND); } public static LogicalExpression or(ExpandCriterion... criterions){ return new LogicalExpression(criterions, Operator.OR); } @SuppressWarnings("rawtypes") public static LogicalExpression in(String fieldName, Collection value, boolean ignoreNull) { if(ignoreNull&&(value==null||value.isEmpty())){ return null; } SimpleExpression[] ses = new SimpleExpression[value.size()]; int i=0; for(Object obj : value){ ses[i]=new SimpleExpression(fieldName,obj,Operator.EQ); i++; } return new LogicalExpression(ses,Operator.OR); }新建SimpleExpression.java
import javax.persistence.criteria.CriteriaBuilder;import javax.persistence.criteria.CriteriaQuery;import javax.persistence.criteria.Expression;import javax.persistence.criteria.Path;import javax.persistence.criteria.Predicate;import javax.persistence.criteria.Root; public class SimpleExpression implements ExpandCriterion{ private String fieldName; //属性名 private Object value; //对应值 private Operator operator; //计算符 protected SimpleExpression(String fieldName, Object value, Operator operator) { this.fieldName = fieldName; this.value = value; this.operator = operator; } public String getFieldName() { return fieldName; } public Object getValue() { return value; } public Operator getOperator() { return operator; } @SuppressWarnings({ "rawtypes", "unchecked" }) public Predicate toPredicate(Root<?> root, CriteriaQuery<?> query, CriteriaBuilder builder) { Path expression = null; if(fieldName.contains(".")){ String[] names = fieldName.split("."); expression = root.get(names[0]); for (int i = 1; i < names.length; i++) { expression = expression.get(names[i]); } }else{ expression = root.get(fieldName); } switch (operator) { case EQ: return builder.equal(expression, value); case NE: return builder.notEqual(expression, value); case LIKE: return builder.like((Expression<String>) expression, "%" + value + "%"); case LT: return builder.lessThan(expression, (Comparable) value); case GT: return builder.greaterThan(expression, (Comparable) value); case LTE: return builder.lessThanOrEqualTo(expression, (Comparable) value); case GTE: return builder.greaterThanOrEqualTo(expression, (Comparable) value); default: return null; } }}LogicalExpression.java
import java.util.ArrayList;import java.util.List; import javax.persistence.criteria.CriteriaBuilder;import javax.persistence.criteria.CriteriaQuery;import javax.persistence.criteria.Predicate;import javax.persistence.criteria.Root; public class LogicalExpression implements ExpandCriterion { private ExpandCriterion[] criterion; // 逻辑表达式中包含的表达式 private Operator operator; //计算符 public LogicalExpression(ExpandCriterion[] criterions, Operator operator) { this.criterion = criterions; this.operator = operator; } public Predicate toPredicate(Root<?> root, CriteriaQuery<?> query, CriteriaBuilder builder) { List<Predicate> predicates = new ArrayList<Predicate>(); for(int i=0;i<this.criterion.length;i++){ predicates.add(this.criterion[i].toPredicate(root, query, builder)); } switch (operator) { case OR: return builder.or(predicates.toArray(new Predicate[predicates.size()])); default: return null; } } }使用criteria前提是dao接口必须实现JpaSpecificationExecutor<T>接口
改造如下
//条件查询 @Override public Paging<Channel> query(Paging<Channel> paging,String channelName,String operator) { Pageable pageReq = new PageRequest(paging.getCurrentPage()-1, paging.getPageSize()); Page<Channel> pageChanel=null; ExpandCriteria<Channel> criteria = new ExpandCriteria<Channel>(); if(StringUtil.isNotEmpty(channelName)){ criteria.add(Restrictions.like("name", channelName, false)); } if(StringUtil.isNotEmpty(operator)){ criteria.add(Restrictions.eq("operator",Operator.valueOf(operator), false)); } pageChanel=channelRepository.findAll(criteria, pageReq); if(pageChanel!=null){ paging.setTotalCount((int)pageChanel.getTotalElements()); paging.setData(pageChanel.getContent()); paging.setTotalPage(pageChanel.getTotalPages()); } return paging; }都不用在dao接口写什么东西
使用方法就是demo
public static void main(String[] args) { //使用示例Demo// Criteria<Entity> c = new Criteria<Entity>();// c.add(Restrictions.like("code", searchParam.getCode(), true)); // c.add(Restrictions.eq("level", searchParam.getLevel(), false)); // c.add(Restrictions.eq("mainStatus", searchParam.getMainStatus(), true)); // c.add(Restrictions.eq("flowStatus", searchParam.getFlowStatus(), true)); // c.add(Restrictions.eq("createUser.userName", searchParam.getCreateUser(), true)); // c.add(Restrictions.lte("submitTime", searchParam.getStartSubmitTime(), true)); // c.add(Restrictions.gte("submitTime", searchParam.getEndSubmitTime(), true)); // c.add(Restrictions.eq("needFollow", searchParam.getIsfollow(), true)); // c.add(Restrictions.ne("flowStatus", searchParam.getMainStatus() true)); // c.add(Restrictions.in("solveTeam.code",teamCodes, true)); // repository.findAll(c); }打包JPA动态查询(CriteriaQuery) eq、ge、gt
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; @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; private Class clazz; private Root from; private List<Predicate> predicates; private CriteriaQuery criteriaQuery; private CriteriaBuilder criteriaBuilder; private List<Order> orders; private Map<String, Query> subQuery; private Map<String, Query> linkQuery; private String projection; 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(); } public static Query forClass(Class clazz, EntityManager entityManager) { return new Query(clazz, entityManager); } 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); } public void addLinkQuery(String propertyName, Query query) { if (this.linkQuery == null) this.linkQuery = new HashMap(); this.linkQuery.put(propertyName, query); } 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); } public void isNull(String propertyName) { this.predicates.add(criteriaBuilder.isNull(from.get(propertyName))); } public void isNotNull(String propertyName) { this.predicates.add(criteriaBuilder.isNotNull(from.get(propertyName))); } public void notEq(String propertyName, Object value) { if (isNullOrEmpty(value)) { return; } this.predicates.add(criteriaBuilder.notEqual(from.get(propertyName), value)); } 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)); } 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)); } 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); } public void le(String propertyName, Number value) { if (isNullOrEmpty(value)) { return; } this.predicates.add(criteriaBuilder.le(from.get(propertyName), value)); } public void lt(String propertyName, Number value) { if (isNullOrEmpty(value)) { return; } this.predicates.add(criteriaBuilder.lt(from.get(propertyName), value)); } public void ge(String propertyName, Number value) { if (isNullOrEmpty(value)) { return; } this.predicates.add(criteriaBuilder.ge(from.get(propertyName), value)); } public void gt(String propertyName, Number value) { if (isNullOrEmpty(value)) { return; } this.predicates.add(criteriaBuilder.gt(from.get(propertyName), value)); } 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); } public void addCriterions(Predicate predicate) { this.predicates.add(predicate); } 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; 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; 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); } 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; } }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; public class Page<T> implements Serializable { private static final long serialVersionUID = 665620345605746930L; private int count; private int pageNo; private int rowsPerPage; private int totalPageCount; private int firstRow; private int lastRow; private List<T> result; 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; } } public int getCount() { return count; } public List<T> getResult() { return result; } public int getPageNo() { return pageNo; } public int getRowsPerPage() { return rowsPerPage; } 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; } 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; @SuppressWarnings({ "unchecked", "rawtypes" }) public class BaseDaoImpl<T> extends EntityManagerFactoryProxy implements IBaseDao { private static Logger log = Logger.getLogger(BaseDaoImpl.class); private int batchSize = 50; public void setBatchSize(int batchSize) { this.batchSize = batchSize; } public <E> E get(Class clazz, Serializable id) { return (E) getEntityManager().find(clazz, id); } 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(); } } 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"); } public void update(Object entity) { if (entity instanceof List) { this.updateList((List) entity); return; } getEntityManager().merge(entity); } public void updateList(List list) { for (Object entity : list) { this.update(entity); } } 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(); } 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"); } 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); } 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(); } 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; } 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); } 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; } public <E extends Serializable> List<E> query(Query query) { return getEntityManager().createQuery(query.newCriteriaQuery()).getResultList(); } 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; @SuppressWarnings({ "rawtypes" }) public interface IBaseDao { public EntityManager getEntityManager(); public <E> E get(Class clazz, Serializable id); public void insert(Object entity); public void update(Object entity); public void updateList(List list); public void delete(Object entity); public void delete(Class entity, List ids); public void delete(Class entity, String jpqlCondition); public Long getCount(Query query); public Long getCount(String jpql); public Page queryPage(Query query, int pageNo, int rowsPerPage); public <E extends Serializable> List<E> query(Query query, int firstResult, int maxResults); public <E extends Serializable> List<E> query(Query query); 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); public <E extends Serializable> List<E> queryBySql(String sql); public <E extends Serializable> List<E> queryBySql(String sql, int firstResult, int maxResults); public <E extends Serializable> List<E> query(Class clazz, String hqlCondition); 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); }关于JPA使用criteria简单查询工具类的方式是什么就分享到这里了，希望以上内容可以对大家有一定的帮助，可以学到更多知识。如果觉得文章不错，可以把它分享出去让更多的人看到。
