conn_manager.java

一套网上书店系统采用JAVABEAN+SERVLET+JSP

package ghy_db;

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

public class Conn_Manager {

	private static ThreadLocal localConn = new ThreadLocal();

	public static Connection getConnection() {

		Connection conn = (Connection) localConn.get();

		try {
			if (conn == null) {

				System.out.println("Conn_Manager类中的conn==null条件成立");
				System.out.println();
				conn = new DB_get_connection().get_conn_from_jdbc();

				localConn.set(conn);

			}

			System.out.println("Conn_Manager类中的getConnection方法中的连接对象为：" + conn);

			conn.setAutoCommit(false);

		} catch (SQLException e) {
			System.out.print("在Conn_Manager的getConnection方法出现异常，错误信息为：");
			e.printStackTrace();
			System.out.println();
		}

		return conn;
	}

	public static void transaction_commit() {
		try {
			Conn_Manager.getConnection().commit();
			Conn_Manager.getConnection().close();
			Conn_Manager.clearConnection();
		} catch (Throwable e) {
			System.out.println("在Conn_Manager中commit时出现异常");
			e.printStackTrace();
		}

	}

	public static void transaction_rollback() {
		try {
			Conn_Manager.getConnection().rollback();
			Conn_Manager.getConnection().close();
			Conn_Manager.clearConnection();
		} catch (Throwable e) {
			System.out.println("在Conn_Manager中rollback时出现异常");
			e.printStackTrace();
		}

	}

	public static void clearConnection() {
		localConn.set(null);
	}
}