Connection conn = null;

Statement stmt = null;

ResultSet rs = null;

String membertype = "";//登录用户类型

try {

StringBuffer sb = new StringBuffer();

sb.append(" select membertype from m_b_broker where brokerid='"+logonUser+"' ");

System.out.print(sb);

rs = stmt.executeQuery(sb.toString());   //这里报出空指针异常

System.out.print("1111");

while (rs.next()) {

membertype=rs.getString("membertype");

}

rs.close();

rs = null;

stmt.close();

stmt = null;

conn.close();

conn = null;

}

catch (Exception e) {

e.printStackTrace();

} finally {

try {

if (rs != null) {

rs.close();

rs = null;

}

if (stmt != null) {

stmt.close();

stmt = null;

}

if (conn != null) {

conn.close();

conn = null;

}

} catch (SQLException e) {

e.printStackTrace();

}

}

return membertype;