abstractdao.java

基于struts的网上商店源码

package com.mole.struts.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;

public abstract class AbstractDAO {

	protected Connection conn;

	public Connection getConn() {

		if (conn == null) {
			try {
				System.out.println("PageData source init...");
				Context ctx = new InitialContext();
				if (ctx == null)
					throw new Exception("Failed to initial context!");
				DataSource ds = (DataSource) ctx
						.lookup("java:comp/env/jdbc/crmdata");
				conn = ds.getConnection();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return conn;
	}

	public ArrayList<Object[]> executeQuery(String sql) {
		Connection conn = getConn();
		PreparedStatement ps = null;
		ResultSet rs = null;
		ArrayList<Object[]> al = new ArrayList<Object[]>();
		Object[] ret = null;
		int num = 0;
		try {
			conn.setAutoCommit(true);
			ps = conn.prepareStatement(sql);
			rs = ps.executeQuery();
			num = rs.getMetaData().getColumnCount();
			while (rs.next()) {
				ret = new Object[num];
				for (int i = 0; i < num; i++)
					ret[i] = rs.getObject(i + 1);
				al.add(ret);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				rs.close();
				ps.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		return al;
	}

	public void executeUpdate(String sql) {
		Connection conn = getConn();
		PreparedStatement ps = null;
		try {
			conn.setAutoCommit(true);
			ps = conn.prepareStatement(sql);
			ps.executeUpdate();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {
				ps.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
}