Hibernate过滤器

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
* 全局Filter 用于自动进行Session和事务的处理
* 
* @author Administrator
* 
*/
public class HibernateFilter implements Filter {

// 初始化日志对象
private static Log log = LogFactory.getLog(HibernateFilter.class);

public void init(FilterConfig config) throws ServletException {
   log.info("servlet filter init.now opening/closing a Session for each request.");
}

public void doFilter(ServletRequest request, ServletResponse response,
    FilterChain chain) throws IOException, ServletException {
   try {
    //开始一个新的事务,(在这个方法中会默认创建一个新的Session)
    HibernateUtil.beginTransaction();
    //进行事务处理
    chain.doFilter(request, response);
    //提交事务
    HibernateUtil.commitTransaction();
   } catch (ServletException se) {
    log.debug("Rolling back the database transaction.");
    //回滚事务，并关闭Session
    HibernateUtil.rollbackTransaction();
    throw se;
   }catch (IOException e) {
    log.debug("Rolling back the database transaction.");
//    回滚事务，并关闭Session
    HibernateUtil.rollbackTransaction();
    throw e;
   }finally{
    //关闭Session
    HibernateUtil.closeSession();
   }

}

public void destroy() {

}

}