linkdb.java

学校期间做的实践项目

package com.computer01.common;

import java.sql.*;

public class Linkdb {

	String strDriver = "org.gjt.mm.mysql.Driver";

	String strConn = "jdbc:mysql://localhost/myportal?useUnicode=true&characterEncoding=GB2312";

	String db_usr = "root";

	String db_password = "123456";

	private Connection conn = null;

	private Statement stmt = null;

	ResultSet rs = null;

	public Linkdb() {
		// 连接MySql_jdbc驱动程序
		try {
			Class.forName(strDriver).newInstance();
		} catch (Exception E) {
			System.err.println("不能连接数据库！");
		}
	}

	// 执行Select语句
	public ResultSet executeQuery(String sql) {
		rs = null;
		try {
			conn = DriverManager.getConnection(strConn, db_usr, db_password);
			stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
					ResultSet.CONCUR_READ_ONLY);
			rs = stmt.executeQuery(sql);
		} catch (SQLException ex) {
			System.err.println("执行SQL语句出错：" + ex.getMessage());
		}
		return rs;
	}

	// 执行Insert,Update语句
	public void executeUpdate(String sql) 
	throws SQLException{
		stmt = null;
		rs = null;
		try {
			conn = DriverManager.getConnection(strConn, db_usr, db_password);

			conn.setAutoCommit(false);
			stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
					ResultSet.CONCUR_READ_ONLY);
			stmt.execute(sql);
			conn.commit();
			stmt.close();
			conn.close();
		} catch (SQLException ex) {
			System.err.println("执行SQL语句出错: " + ex.getMessage());
			throw ex;
		}
	}

	public void closeStmt() {
		try {
			stmt.close();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	public void closeConn() {
		try {
			conn.close();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
}