能做事务的JdbcUtils工具

JdbcUtils工具类的封装

package cn.wht.utils;

import java.sql.Connection;
import java.sql.SQLException;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class JdbcUtils {

	private static DataSource dataSource=null;                             //数据源
	private static final ThreadLocal<Connection> threadLocal=new ThreadLocal<Connection>();   //绑定连接的线程容器
	static{
		dataSource=new ComboPooledDataSource();
	}
	
	/**
	 * 获取连接池
	 * @return
	 */
	public static DataSource getDataSource(){
		return dataSource;
	}
	/**
	 * 获取连接
	 * @return 数据库的一个连接
	 */
	public static Connection  getConnection(){
		try {
			Connection connection=threadLocal.get();
			if(connection==null){
				connection=dataSource.getConnection();
				threadLocal.set(connection);
				return connection;
			}else{
				return connection;
			}
			 
		} catch (SQLException e) {
			
			throw new RuntimeException(e);
		}
	}
	/**
	 * 关闭连接
	 */
	public static void close(){
		Connection connection=threadLocal.get();
		if(connection!=null){
			try {
				connection.close();
			} catch (SQLException e) {
				throw new RuntimeException(e);
			}finally{
				threadLocal.remove();
			}
		}
	}
	/**
	 * 
	 * 开启事务
	 */
	public static void startTransaction(){
		try {
			Connection connection=getConnection();
			threadLocal.set(connection);
			connection.setAutoCommit(true);
		} catch (SQLException e) {
			throw new RuntimeException(e);
		}
	}
	
	/**
	 * 提交事务
	 */
	public static void commit(){
		
		
		try {
			Connection connection=threadLocal.get();
			if(connection!=null){
				connection.commit();
			}
		} catch (SQLException e) {
			throw new RuntimeException(e);
		}
	}
	
	/**
	 * 回滚事务
	 */
	public static void rollback(){
		try {
			Connection connection=threadLocal.get();
			if(connection!=null){
				connection.rollback();
			}
		} catch (SQLException e) {
			throw new RuntimeException(e);
		}
	}
}

package cn.wht.filter;

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 javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import cn.wht.utils.JdbcUtils;

public class OpenTransactionInViewFilter implements Filter {

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		// TODO Auto-generated method stub

	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		request=(HttpServletRequest) request;
		response=(HttpServletResponse) response;
		try{
			JdbcUtils.startTransaction();
			
			chain.doFilter(request, response);
			
			JdbcUtils.commit();
		}catch(Exception e){
			JdbcUtils.rollback();
			//跳转到错误页面
                        request.getRequestDispatcher("/error.jsp").forward(request, response);
		}finally{
			JdbcUtils.close();
		}
		
		
		

	}

	@Override
	public void destroy() {
		// TODO Auto-generated method stub

	}

}