Struts2 + Spring + Hibernate 通用 Service 和 DAO

我在 Struts2 + Spring + Hibernate  项目开发中总结出了一个Service 和 DAO ，可以用于处理任何的pojo（bean）。使用这两个Service 和 DAO 可以极大地提高开发的效率，不必再分别针对不同的pojo编写对应的Service 和 DAO。内容如下：

DAO：

接口：BaseDao.java

package dao;

import java.util.List;

/**
 * @author 雷霄骅
 * 对Object的DAO操作
 * 提供了通用的一些方法
 */

public interface BaseDao {
	public void save(Object object);
	public void delete(Object object);
	public void update(Object object);
	public Object ReadSingle(String targetName,String propertyName,Object value);
	public List<Object> ReadByProperty(String targetName,String propertyName,Object value);
	public List<Object> ReadAll(String targetName);
	public List<Object> ReadAllByOrder(String targetName,String propertyName,String order);
	public Object get(int id);
	public List<Object> ReadByPropertyList(String targetName,List<String> propertyName, List<Object> value);
	public Integer ReadCount(String targetName);
	public List<Object> ReadLimitedByOrder(String targetName, String propertyName,int num, String order);
}

实现：BaseDaoImpl.java

package dao;

import java.sql.SQLException;
import java.util.List;

import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

/**
 * @author 雷霄骅
 * HibernateTemplate提供非常多的常用方法来完成基本的操作，比如通常的增加、删除、修改、查询等操作，
 * Spring 2.0更增加对命名SQL查询的支持，也增加对分页的支持。大部分情况下，就可完成大多数DAO对象的CRUD操作。
 */
public class BaseDaoImpl extends HibernateDaoSupport implements BaseDao{

	@Override
	public void save(Object object) {
		getHibernateTemplate().save(object);
		//System.out.println("save "+object.toString());
	}

	@Override
	public void delete(Object object) {
		getHibernateTemplate().delete(object);
	}

	@Override
	public void update(Object object) {
		getHibernateTemplate().update(object);
		//改用saveOrUpdate，在评价的时候，第一次创建的时候Save，其他时候Update
		//getHibernateTemplate().saveOrUpdate(object);
		//System.out.println("update "+object.toString());
	}

	@SuppressWarnings("unchecked")
	@Override
	public Object ReadSingle(final String targetName,final String propertyName, final Object value) {
		// TODO Auto-generated method stub
		return (Object) getHibernateTemplate().execute(new HibernateCallback() {
			/*doInHibernate()。session的创建和销毁，一切都在程序内部完成。*/
			public Object doInHibernate(Session session)
					throws HibernateException, SQLException {
				String hql = "from "+targetName+" as "+targetName+" where "+targetName+"." + propertyName + "=:value";
				Query query = session.createQuery(hql);
				query.setParameter("value", value);
				return query.uniqueResult();
			}
		});
	}

	@SuppressWarnings("unchecked")
	@Override
	public List<Object> ReadAll(String targetName) {
		// TODO Auto-generated method stub
		String hql="from "+targetName;
		return getHibernateTemplate().find(hql);
	}

	@SuppressWarnings("unchecked")
	@Override
	public List<Object> ReadByProperty(final String targetName, final String propertyName,
			final Object value) {
		// TODO Auto-generated method stub
		return (List<Object>) getHibernateTemplate().execute(new HibernateCallback() {
			/*doInHibernate()。session的创建和销毁，一切都在程序内部完成。*/
			public Object doInHibernate(Session session)
					throws HibernateException, SQLException {
				String hql = "from "+targetName+" as "+targetName+" where "+targetName+"." + propertyName + "=:value";
				Query query = session.createQuery(hql);
				query.setParameter("value", value);
				return query.list();
			}
		});
	}
	//比ReadByProperty简单很多
	@Override
	public Object get(int id) {
		// TODO Auto-generated method stub
		return getHibernateTemplate().get(Object.class, id);
	}

	@Override
	public List<Object> ReadByPropertyList(final String targetName,
			final List<String> propertyName, final List<Object> value) {
		// TODO Auto-generated method stub
		return (List<Object>) getHibernateTemplate().execute(new HibernateCallback() {
			/*doInHibernate()。session的创建和销毁，一切都在程序内部完成。*/
			public Object doInHibernate(Session session) throws HibernateException, SQLException {
				String hql = "from "+targetName+" as "+targetName;

				//-------------------------------
				for(int i=0;i<propertyName.size();i++){
				    String propertynametemp= propertyName.get(i);
				    Object propertyvaluetemp= value.get(i);
					if(propertynametemp!=null){
				     if(i==0){
				      hql=hql+" where "+targetName+"." + propertynametemp + "=" + propertyvaluetemp +" ";
				     }else{
				    	 hql=hql+" and "+targetName+"." +propertynametemp + "=" + propertyvaluetemp +" ";
				     }
					}
				}
				//-------------------------------
					Query query = session.createQuery(hql);
				//当返回的数据不是一条的时候，不用uniqueresult()，而用list()
				return query.list();
			}
		});
	}
//这里在Hibernate2.0之前版本list.get(0)返回的是Integer类型.
//但是在Hibernate3.0以后版本list.get(0)返回的是Long类型.
//所以在这里不可以由Long型强转成Integer类型.
//Integer属于不可更改类型，而且Long和Integer没有任何继承关系，当然不能这样转换。
	@Override
	public Integer ReadCount(final String targetName) {
		// TODO Auto-generated method stub
		return (Integer) getHibernateTemplate().execute(new HibernateCallback() {
			/*doInHibernate()。session的创建和销毁，一切都在程序内部完成。*/
			public Object doInHibernate(Session session)
					throws HibernateException, SQLException {
				String hql = "select count(*) from "+targetName;
				//System.out.println(hql);
				//注:java.lang.Number是Integer,Long的父类.
				return ((Number)session.createQuery(hql).iterate().next()).intValue();
			}
		});
	}

	@Override
	public List<Object> ReadLimitedByOrder(final String targetName,
			final String propertyName, final int num, final String order) {
		// TODO Auto-generated method stub
		return (List<Object>) getHibernateTemplate().execute(new HibernateCallback() {
			/*doInHibernate()。session的创建和销毁，一切都在程序内部完成。*/
			public Object doInHibernate(Session session) throws HibernateException, SQLException {
				String hql ="from "+targetName+" as "+targetName+ " order by "+targetName+"." + propertyName+ " " + order;
				Query query = session.createQuery(hql);
				query.setMaxResults(num);
				//当返回的数据不是一条的时候，不用uniqueresult()，而用list()
				return query.list();
			}
		});
	}

	@Override
	public List<Object> ReadAllByOrder(String targetName, String propertyName,
			String order) {
		// TODO Auto-generated method stub
		String hql="from "+targetName+" as "+targetName+ " order by "+targetName+"." + propertyName+ " " + order;
		return getHibernateTemplate().find(hql);
	}

}

Service：

接口：BaseService.java

package service;

import java.util.List;

/**
 * @author 雷霄骅
 * 对Object的Service
 * 提供了一些通用的方法
 */
public interface BaseService {
	 public void save(Object object);
	 public void update(Object object);
	 public void delete(Object object);
	 public Object ReadByID(String targetName,int id);
	 @SuppressWarnings("rawtypes")
	 public List ReadAll(String targetName);
	 public List ReadAllByOrder(String targetName,String propertyName,String order);
	 @SuppressWarnings("rawtypes")
	 public List ReadByProperty(String targetName,String propertyName,Object propertyValue);
	 public List ReadByPropertyList(String targetName,List<String> propertyName,List<Object> propertyValue);
	 public List ReadLimitedByOrder(String targetName,String propertyName,int num,String order);
	 public Object ReadSingle(String targetName,String propertyName,Object propertyValue);
	 public int ReadCount(String targetName);

}

实现：BaseServiceImpl.java

package service;

import java.util.ArrayList;
import java.util.List;

import dao.BaseDao;
/**
 * @author 雷霄骅
 * 对Object的Service
 * 提供了一些通用的方法
 */
public class BaseServiceImpl implements BaseService {

	private BaseDao baseDao;
	@Override
	public void save(Object object) {
		// TODO Auto-generated method stub
		baseDao.save(object);
	}

	@Override
	public void update(Object object) {
		// TODO Auto-generated method stub
		baseDao.update(object);
	}

	@Override
	public void delete(Object object) {
		// TODO Auto-generated method stub
		baseDao.delete(object);
	}

	@Override
	public Object ReadByID(String targetName,int id) {
		// TODO Auto-generated method stub
		return baseDao.ReadSingle(targetName,"id", id);
	}

	@SuppressWarnings("rawtypes")
	@Override
	public List ReadAll(String targetName) {
		// TODO Auto-generated method stub
		return baseDao.ReadAll(targetName);
	}

	@SuppressWarnings("rawtypes")
	@Override
	public List ReadAllByOrder(String targetName,String propertyName,String order) {
		// TODO Auto-generated method stub
		return baseDao.ReadAllByOrder(targetName,propertyName,order);
	}

	public BaseDao getBaseDao() {
		return baseDao;
	}

	public void setBaseDao(BaseDao baseDao) {
		this.baseDao = baseDao;
	}

	@Override
	public List ReadByProperty(String targetName, String propertyName,
			Object propertyValue) {
		// TODO Auto-generated method stub
		return baseDao.ReadByProperty(targetName, propertyName, propertyValue);
	}

	@Override
	public Object ReadSingle(String targetName, String propertyName,
			Object propertyValue) {
		// TODO Auto-generated method stub
		return baseDao.ReadSingle(targetName, propertyName, propertyValue);
	}

	@Override
	public int ReadCount(String targetName) {
		// TODO Auto-generated method stub
		return baseDao.ReadCount(targetName);
	}

	@Override
	public List ReadLimitedByOrder(String targetName, String propertyName,
			int num, String order) {
		return baseDao.ReadLimitedByOrder(targetName,propertyName,num,order);
	}

	@Override
	public List ReadByPropertyList(String targetName,
			List<String> propertyName, List<Object> propertyValue) {
		// TODO Auto-generated method stub
		return baseDao.ReadByPropertyList(targetName,propertyName,propertyValue);
	}

}

这样，在Action层调用方法的时候，可以直接调用BaseService相应的方法完成操作。

举一个例子：

有这么一个名字叫Blog的pojo：

package bean;

import java.sql.Timestamp;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

/**
 * Blog entity. @author MyEclipse Persistence Tools
 */
@Entity
@Table(name = "blog", catalog = "vqe")
public class Blog implements java.io.Serializable {

	// Fields

	private Integer id;
	private Admin admin;
	private String title;
	private Timestamp modifytime;
	private String content;

	// Constructors

	/** default constructor */
	public Blog() {
	}

	/** full constructor */
	public Blog(Admin admin, String title, Timestamp modifytime, String content) {
		this.admin = admin;
		this.title = title;
		this.modifytime = modifytime;
		this.content = content;
	}

	// Property accessors
	@Id
	@GeneratedValue(strategy = IDENTITY)
	@Column(name = "id", unique = true, nullable = false)
	public Integer getId() {
		return this.id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	@ManyToOne(fetch = FetchType.EAGER)
	@JoinColumn(name = "adminid")
	public Admin getAdmin() {
		return this.admin;
	}

	public void setAdmin(Admin admin) {
		this.admin = admin;
	}

	@Column(name = "title", length = 200)
	public String getTitle() {
		return this.title;
	}

	public void setTitle(String title) {
		this.title = title;
	}

	@Column(name = "modifytime", length = 19)
	public Timestamp getModifytime() {
		return this.modifytime;
	}

	public void setModifytime(Timestamp modifytime) {
		this.modifytime = modifytime;
	}

	@Column(name = "content", length = 10000)
	public String getContent() {
		return this.content;
	}

	public void setContent(String content) {
		this.content = content;
	}

}

该类代表博客的一篇文章。

在Action层只需调用BaeService对应的方法就能完成相应的操作。换句话说，只要把pojo的类的名字当一个字符串传递给ReadByID这种的函数，就可以实现相应的功能。

//根据ID读取：
Blog blog=(Blog) baseService.ReadByID("Blog", blogid);
//添加：
baseService.save(blog);
//修改：
baseService.update(blog);
//删除：
baseService.delete(blog);
//读取所有（根据时间降序）
List<Blog> resultblog=baseService.ReadAllByOrder("Blog","modifytime","desc");
//读取num条（根据时间降序）
List<Blog> resultblog=baseService.ReadLimitedByOrder("Blog","modifytime",num,"desc");

完整的实现Blog（博客）的增删改查的Action示例：

package action;

import java.sql.Timestamp;
import java.util.Date;
import java.util.List;
import java.util.Map;

import service.BaseService;

import bean.Admin;
import bean.Blog;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
/**
 * @author 雷霄骅
 * Action
 */
public class BlogAct extends ActionSupport {
	private int blogid;
	private int num;
	private Blog blog;
	private List<Blog> resultblog;
	private BaseService baseService;

	public int getBlogid() {
		return blogid;
	}

	public void setBlogid(int blogid) {
		this.blogid = blogid;
	}

	public Blog getBlog() {
		return blog;
	}

	public void setBlog(Blog blog) {
		this.blog = blog;
	}

	public BaseService getBaseService() {
		return baseService;
	}

	public void setBaseService(BaseService baseService) {
		this.baseService = baseService;
	}

	public List<Blog> getResultblog() {
		return resultblog;
	}

	public void setResultblog(List<Blog> resultblog) {
		this.resultblog = resultblog;
	}

	public int getNum() {
		return num;
	}

	public void setNum(int num) {
		this.num = num;
	}

	public String Add(){
		try{
			//--------------------------------
			ActionContext context = ActionContext.getContext();
			Map sessionMap = context.getSession();
			Admin admin=(Admin)sessionMap.get("admin");
			//--------------------------------
			blog.setModifytime( new Timestamp(new Date().getTime()));
			blog.setAdmin(admin);
			baseService.save(blog);
			return SUCCESS;
		}
		catch(Exception ex){
			ex.printStackTrace();
			return ERROR;
		}
	}

	public String Delete(){
		try{
			blog=(Blog) baseService.ReadByID("Blog", blogid);
			baseService.delete(blog);
			return SUCCESS;
		}
		catch(Exception ex){
			ex.printStackTrace();
			return ERROR;
		}
	}

	public String Read(){
		try{
			blog=(Blog) baseService.ReadByID("Blog", blogid);
			return SUCCESS;
		}
		catch(Exception ex){
			ex.printStackTrace();
			return ERROR;
		}
	}

	public String Update(){
		try{
			//--------------------------------
			ActionContext context = ActionContext.getContext();
			Map sessionMap = context.getSession();
			Admin admin=(Admin)sessionMap.get("admin");
			//--------------------------------
			blog.setModifytime( new Timestamp(new Date().getTime()));
			blog.setAdmin(admin);
			baseService.update(blog);
			return SUCCESS;
		}
		catch(Exception ex){
			ex.printStackTrace();
			return ERROR;
		}
	}

	public String ReadAll(){
		try{
			resultblog=baseService.ReadAllByOrder("Blog","modifytime","desc");
			return SUCCESS;
		}
		catch(Exception ex){
			ex.printStackTrace();
			return ERROR;
		}
	}

	public String ReadLimitedByOrder(){
		try{
			resultblog=baseService.ReadLimitedByOrder("Blog","modifytime",num,"desc");
			return SUCCESS;
		}
		catch(Exception ex){
			ex.printStackTrace();
			return ERROR;
		}
	}
}