JSP连接sql2000出错

DBC代码/**
 * 数据库连接
 */
package dbcon;import java.sql.*;/**
 * @author Administrator
 * 
 */
public class DBConnect { // 驱动
private static final String DRIVERCLASS = "com.microsoft.jdbc.sqlserver.SQLServerDriver"; // 连接
// public final static String DBURL =
// "jdbc:microsoft:sqlserver://127.0.0.1:1433;DatabaseName=master";
protected final String DBURL = "jdbc:microsoft:sqlserver://127.0.0.1:1433;DatabaseName=txl"; // 数据库用户
public final static String DBUSER = "sa"; // 密码
public final static String USERPWD = "1111"; // 连接
public Connection conn; // SQL 执行器
public Statement stmt; // 结果集
public ResultSet rs;
// 静态块，只加载一次
static {
// 加载驱动
try { Class.forName(DRIVERCLASS); } catch (ClassNotFoundException e) { // 加载驱动异常
System.out.println("加载驱动异常");
e.printStackTrace();
}
} /**
 * 打开连接
 * 
 */
public boolean openConn() {
boolean isOpen = true;
try {
conn = DriverManager.getConnection(DBURL, DBUSER, USERPWD);
System.out.println("数据库连接ok");

stmt=conn.createStatement();
} catch (SQLException e) {
isOpen = false;
System.out.println("数据库连接异常");
e.printStackTrace();
}
return isOpen;
} /**
 * 打开连接
 * 
 */
public boolean closeConn() {
boolean isOpen = true;
try {
conn.close();
} catch (SQLException e) {
isOpen = false;
System.out.println("数据库连接异常");
e.printStackTrace();
}
return isOpen;
} /**
 * @param args
 */
public static void main(String[] args) {
// TODO Auto-generated method stub
DBConnect a = new DBConnect();
a.openConn();
}}
错误提示：TDSConnection.<init>(String, String, BaseExceptions) line: not available
SQLServerImplConnection.open() line: not available [local variables unavailable]
SQLServerConnection(BaseConnection).getNewImplConnection(boolean, int) line: not available
SQLServerConnection(BaseConnection).open(BaseConnectionProperties, BaseExceptions) line: not available
SQLServerDriver(BaseDriver).connect(String, Properties) line: not available
DriverManager.getConnection(String, Properties, ClassLoader) line: not available
DriverManager.getConnection(String, String, String) line: not available
DBoprate(DBConnect).openConn() line: 58
login.jsp line: 16
login_jsp(Htlogin_jsp(HttpServlet).service(ServletRequest, ServletResponse) line: 729
tpJspBase).service(HttpServletRequest, HttpServletResponse) line: 98
JspServletWrapper.service(HttpServletRequest, HttpServletResponse, boolean) line: 331
JspServlet.serviceJspFile(HttpServletRequest, HttpServletResponse, String, Throwable, boolean) line: 329
JJspServlet(HttpServlet).service(ServletRequest, ServletResponse) line: 729
spServlet.service(HttpServletRequest, HttpServletResponse) line: 265
ApplicationFilterChain.internalDoFilter(ServletRequest, ServletResponse) line: 269
ApplicationFilterChain.doFilter(ServletRequest, ServletResponse) line: 188 各位大侠救救我啊