genericdaoimpl.java

EasyJWeb是基于java技术

package com.easyjf.core.dao.impl;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceException;
import javax.persistence.Query;

import org.springframework.orm.jpa.JpaCallback;
import org.springframework.orm.jpa.support.JpaDaoSupport;

import com.easyjf.core.dao.CanotRemoveObjectException;
import com.easyjf.core.dao.GenericDAO;

public class GenericDAOImpl<T> extends JpaDaoSupport implements GenericDAO<T> {

	private Class<T> clazz;

	public GenericDAOImpl(Class<T> clazz) {
		this.clazz = clazz;
	}

	/*
	 * public void setClazz(Class<T> clazz) { this.clazz =
	 * clazz; } public Class<T> getClazz() { return clazz; }
	 */
	public T get(Serializable id) {
		if (id == null)
			return null;
		return this.getJpaTemplate().find(clazz, id);
	}

	public List<T> find(final String queryStr, final Object[] params,
			final int begin, final int max) {
		// TODO Auto-generated method stub
		List<T> ret = (List<T>) this.getJpaTemplate().execute(
				new JpaCallback() {

					public Object doInJpa(EntityManager em)
							throws PersistenceException {
						// TODO Auto-generated method stub
						String clazzName = clazz.getName();
						StringBuffer sb = new StringBuffer("select obj from ");
						sb.append(clazzName).append(" obj").append(" where ")
								.append(queryStr);
						Query query = em.createQuery(sb.toString());
						int parameterIndex = 1;
						if (params != null && params.length > 0) {
							for (Object obj : params) {
								query.setParameter(parameterIndex++, obj);
							}
						}
						if (begin >= 0 && max > 0) {
							query.setFirstResult(begin);
							query.setMaxResults(max);
						}
						if (begin >= 0 && max > 0) {
							query.setFirstResult(begin);
							query.setMaxResults(max);
						}
						return query.getResultList();
					}
				});
		if (ret != null && ret.size() >= 0) {
			return ret;
		} else {
			return new ArrayList<T>();
		}
	}

	public List query(final String queryStr, final Object[] params,
			final int begin, final int max) {
		// TODO Auto-generated method stub
		List ret = (List) this.getJpaTemplate().execute(new JpaCallback() {

			public Object doInJpa(EntityManager em) throws PersistenceException {
				// TODO Auto-generated method stub
				Query query = em.createQuery(queryStr);
				int parameterIndex = 1;
				if (params != null && params.length > 0) {
					for (Object obj : params) {
						query.setParameter(parameterIndex++, obj);
					}
				}
				if (begin >= 0 && max > 0) {
					query.setFirstResult(begin);
					query.setMaxResults(max);
				}
			/*	if (begin >= 0 && max > 0) {
					query.setFirstResult(begin);
					query.setMaxResults(max);
				}*/
				return query.getResultList();
			}
		});
		if (ret != null && ret.size() >= 0) {
			return ret;
		} else {
			return new ArrayList();
		}
	}

	public void remove(Serializable id) throws CanotRemoveObjectException {
		// TODO Auto-generated method stub
		if (id == null)
			throw new java.lang.IllegalArgumentException("id值不能为空!");
		T object = this.get(id);
		if (object != null) {
			try {
				this.getJpaTemplate().remove(object);
			} catch (Exception e) {
				throw new CanotRemoveObjectException();
			}
		}
	}

	public void save(T instance) {
		// TODO Auto-generated method stub
		// this.getJpaTemplate().getEntityManager().joinTransaction();
		this.getJpaTemplate().persist(instance);
	}

	public T getBy(final String propertyName, final Object value) {
		if (propertyName == null || "".equals(propertyName) || value == null)
			throw new IllegalArgumentException("调用参数不正确，属性名称及值均不能为空!");
		// TODO Auto-generated method stub
		List<T> ret = (List<T>) this.getJpaTemplate().execute(
				new JpaCallback() {

					public Object doInJpa(EntityManager em)
							throws PersistenceException {
						// TODO Auto-generated method stub
						String clazzName = clazz.getName();
						StringBuffer sb = new StringBuffer("select obj from ");
						sb.append(clazzName).append(" obj");
						Query query = null;
						if (propertyName != null && value != null) {
							sb.append(" where obj.").append(propertyName)
									.append(" = :value");
							query = em.createQuery(sb.toString()).setParameter(
									"value", value);
						} else {
							query = em.createQuery(sb.toString());
						}
						return query.getResultList();
					}
				});
		if (ret != null && ret.size() == 1) {
			return ret.get(0);
		} else if (ret != null && ret.size() > 1) {
			throw new java.lang.IllegalStateException(
					"worning  --more than one object find!!");
		} else {
			return null;
		}
	}

	public void update(T instance) {
		// TODO Auto-generated method stub
		this.getJpaTemplate().merge(instance);
	}

	public void setClazzType(Class clazz) {
		this.clazz = clazz;
	}

	public Class getClassType() {
		return this.clazz;
	}

	public List executeNativeNamedQuery(final String nnq) {
		Object ret = this.getJpaTemplate().execute(new JpaCallback() {

			public Object doInJpa(EntityManager em) throws PersistenceException {
				Query query = em.createNativeQuery(nnq);
				return query.getResultList();
			}
		});
		return (List) ret;
	}

	public int executeNativeSQL(final String nnq) {
		Object ret = this.getJpaTemplate().execute(new JpaCallback() {

			public Object doInJpa(EntityManager em) throws PersistenceException {
				Query query = em.createNativeQuery(nnq);
				query.executeUpdate();
				return null;
			}
		});
		return (Integer) ret;
	}

	public int batchUpdate(final String jpql, final Object[] params) {
		Object ret = this.getJpaTemplate().execute(new JpaCallback() {

			public Object doInJpa(EntityManager em) throws PersistenceException {
				Query query = em.createQuery(jpql);
				int parameterIndex = 1;
				if (params != null && params.length > 0) {
					for (Object obj : params) {
						query.setParameter(parameterIndex++, obj);
					}
				}
				return query.executeUpdate();
			}
		});
		return (Integer) ret;
	}

	public void flush() {
		this.getJpaTemplate().execute(new JpaCallback() {

			public Object doInJpa(EntityManager em) throws PersistenceException {
				em.getTransaction().commit();
				return null;
			}
		});
	}

}