basedao.java

一个简单的Struts的例子

package com.hacker.common;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.PreparedStatement;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;

public class BaseDao {
	private Connection con = null;
	private Statement stmt = null;
	private ResultSet rs = null;
	private PreparedStatement pstmt = null;
	public BaseDao(){
		Context ctx;
		try {
			ctx = new InitialContext();
			DataSource ds = (DataSource)ctx.lookup("java:/comp/env/jdbc/sqlServer");
			con = ds.getConnection();
			stmt = con.createStatement();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	public void executeUpdate(String sql) throws SQLException{
		stmt.executeUpdate(sql);
	}
	public ResultSet executeQuery(String sql) throws SQLException{
		 rs = stmt.executeQuery(sql);
		 return rs;
	}
	public PreparedStatement getPstmt(String sql) throws SQLException{
		pstmt = con.prepareStatement(sql);
		return pstmt;
	}
	public void executeUpdate() throws SQLException{
		pstmt.executeBatch();
	}
	public void close(){
		if(rs != null){
			try {
				rs.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if(stmt != null){
			try {
				stmt.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if(pstmt != null){
			try {
				pstmt.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if(con != null){
			try {
				con.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
}