1.
1 package com.sanqing.dao; 2 3 import java.io.Serializable; 4 import java.util.LinkedHashMap; 5 6 import com.sanqing.util.QueryResult; 7 8 9 public interface DAO<T> { 10 public long getCount();//获得记录总数 11 public void clear();//清除一级缓存的数据 12 public void save(Object entity);//保存记录 13 public void update(Object entity);//更新记录 14 public void delete(Serializable ... entityids);//删除记录 15 public T find(Serializable entityId);//通过主键获得记录 16 public QueryResult<T> getScrollData(int firstindex, int maxresult, String wherejpql, 17 Object[] queryParams,LinkedHashMap<String, String> orderby);//获得分页记录 18 public QueryResult<T> getScrollData(int firstindex, int maxresult, 19 String wherejpql, Object[] queryParams);//获得分页记录 20 public QueryResult<T> getScrollData(int firstindex, int maxresult, 21 LinkedHashMap<String, String> orderby);//获得分页记录 22 public QueryResult<T> getScrollData(int firstindex, int maxresult); //获得分页记录 23 public QueryResult<T> getScrollData();//获得分页记录 24 }
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1 package com.sanqing.dao; 2 3 import java.beans.Introspector; 4 import java.beans.PropertyDescriptor; 5 import java.io.Serializable; 6 import java.lang.reflect.Method; 7 import java.util.LinkedHashMap; 8 9 import javax.persistence.EmbeddedId; 10 import javax.persistence.Entity; 11 import javax.persistence.EntityManager; 12 import javax.persistence.PersistenceContext; 13 import javax.persistence.Query; 14 15 import org.springframework.transaction.annotation.Propagation; 16 import org.springframework.transaction.annotation.Transactional; 17 18 import com.sanqing.util.GenericsUtils; 19 import com.sanqing.util.QueryResult; 20 21 @SuppressWarnings("unchecked") 22 @Transactional 23 public abstract class DaoSupport<T> implements DAO<T>{ 24 protected Class<T> entityClass = GenericsUtils.getSuperClassGenricType(this.getClass());//获得该类的父类的泛型参数的实际类型 25 @PersistenceContext protected EntityManager em; 26 public void clear(){//清除一级缓存的数据 27 em.clear(); 28 } 29 public void delete(Serializable ... entityids) {//删除记录 30 for(Object id : entityids){ 31 em.remove(em.getReference(this.entityClass, id)); 32 } 33 } 34 @Transactional(readOnly=true,propagation=Propagation.NOT_SUPPORTED) 35 public T find(Serializable entityId) {//通过主键获得记录 36 if(entityId==null) throw new RuntimeException(this.entityClass.getName()+ ":传入的实体id不能为空"); 37 return em.find(this.entityClass, entityId); 38 } 39 public void save(Object entity) {//保存记录 40 em.persist(entity); 41 } 42 @Transactional(readOnly=true,propagation=Propagation.NOT_SUPPORTED) 43 public long getCount() { //获得记录总数 44 return (Long)em.createQuery("select count("+ getCountField(this.entityClass) +") from "+ getEntityName(this.entityClass)+ " o").getSingleResult(); 45 } 46 47 protected static <E> String getCountField(Class<E> clazz){ 48 String out = "o"; 49 try { 50 PropertyDescriptor[] propertyDescriptors = Introspector.getBeanInfo(clazz).getPropertyDescriptors(); 51 for(PropertyDescriptor propertydesc : propertyDescriptors){ 52 Method method = propertydesc.getReadMethod(); 53 if(method!=null && method.isAnnotationPresent(EmbeddedId.class)){ 54 PropertyDescriptor[] ps = Introspector.getBeanInfo(propertydesc.getPropertyType()).getPropertyDescriptors(); 55 out = "o."+ propertydesc.getName()+ "." + (!ps[1].getName().equals("class")? ps[1].getName(): ps[0].getName()); 56 break; 57 } 58 } 59 } catch (Exception e) { 60 e.printStackTrace(); 61 } 62 return out; 63 } 64 65 protected static void setQueryParams(Query query, Object[] queryParams){ 66 if(queryParams!=null && queryParams.length>0){ 67 for(int i=0; i<queryParams.length; i++){ 68 query.setParameter(i+1, queryParams[i]); 69 } 70 } 71 } 72 protected static String buildOrderby(LinkedHashMap<String, String> orderby){//组装order by语句 73 StringBuffer orderbyql = new StringBuffer(""); 74 if(orderby!=null && orderby.size()>0){ 75 orderbyql.append(" order by "); 76 for(String key : orderby.keySet()){ 77 orderbyql.append("o.").append(key).append(" ").append(orderby.get(key)).append(","); 78 } 79 orderbyql.deleteCharAt(orderbyql.length()-1); 80 } 81 return orderbyql.toString(); 82 } 83 protected static <E> String getEntityName(Class<E> clazz){//获取实体的名称 84 String entityname = clazz.getSimpleName(); 85 Entity entity = clazz.getAnnotation(Entity.class); 86 if(entity.name()!=null && !"".equals(entity.name())){ 87 entityname = entity.name(); 88 } 89 return entityname; 90 } 91 92 public void update(Object entity) {//更新记录 93 em.merge(entity); 94 } 95 @Transactional(readOnly=true,propagation=Propagation.NOT_SUPPORTED) 96 public QueryResult<T> getScrollData(int firstindex, 97 int maxresult, LinkedHashMap<String, String> orderby) {//获得分页记录 98 return getScrollData(firstindex,maxresult,null,null,orderby); 99 } 100 @Transactional(readOnly=true,propagation=Propagation.NOT_SUPPORTED) 101 public QueryResult<T> getScrollData(int firstindex, 102 int maxresult, String wherejpql, Object[] queryParams) {//获得分页记录 103 return getScrollData(firstindex,maxresult,wherejpql,queryParams,null); 104 } 105 @Transactional(readOnly=true,propagation=Propagation.NOT_SUPPORTED) 106 public QueryResult<T> getScrollData(int firstindex, int maxresult) {//获得分页记录 107 return getScrollData(firstindex,maxresult,null,null,null); 108 } 109 @Transactional(readOnly=true,propagation=Propagation.NOT_SUPPORTED) 110 public QueryResult<T> getScrollData() { 111 return getScrollData(-1, -1); 112 } 113 @Transactional(readOnly=true,propagation=Propagation.NOT_SUPPORTED) 114 public QueryResult<T> getScrollData(int firstindex, int maxresult, String wherejpql, 115 Object[] queryParams,LinkedHashMap<String, String> orderby) {//获得分页记录 116 QueryResult qr = new QueryResult<T>();//查询记录结果 117 String entityname = getEntityName(this.entityClass);//获得实体名称 118 Query query = em.createQuery("select o from "+ 119 entityname+ " o "+(wherejpql==null 120 || "".equals(wherejpql.trim())? "": 121 "where "+ wherejpql)+ buildOrderby(orderby));//执行查询 122 setQueryParams(query, queryParams);//设置查询参数 123 if(firstindex!=-1 && maxresult!=-1) //两个参数都不是-1的时候才分页 124 query.setFirstResult(firstindex). 125 setMaxResults(maxresult);//设置查询记录的起始位置和查询最大数 126 qr.setResultlist(query.getResultList());//设置查询的记录 127 query = em.createQuery("select count(" + 128 getCountField(this.entityClass)+ ") " + 129 "from "+ entityname+ " o "+(wherejpql==null || 130 "".equals(wherejpql.trim())? "": "where "+ wherejpql)); 131 setQueryParams(query, queryParams);//设置查询参数 132 qr.setTotalrecord((Long)query.getSingleResult());//设置查询记录总数 133 return qr;//返回查询记录结果 134 } 135 136 137 }