jsp调用数据库问题，求解答

2016-10-06 01:10:31 193 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

JSP-课后答案《JSP实用教程（第三版）》课后答案第 1 章 JSP 1. 安装 Tomcat引擎的计算机需要事先安装 JDK 吗？答：需要 2. 怎样启动和关闭 Tomcat服务器 ? 答：bin 目录下使用 startup.bat启动 Tomcat服务器。bin 目录下使用 shutdown.bat关闭 Tomcat服务 3. Boy.jsp和 boy.jsp是否是相同的 JSP 文件名字？答：答：不是 4. 请在下建立一个名字为 water 的目录，并将该目录设置成一个 Web 服务目录，阅读详情

<%@page contentType="text/html; charset=utf-8"%>
<%@page import="java.sql.*"%>
<html>
<body >
<%
Connection con;
Statement sql;
ResultSet rs;
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
}catch(Exception e){
out.print(e);
}
try{
con = DriverManager.getConnection("jdbc:odbc:flower","flower","123456");
sql = con.createStatement();
rs = sql.executeQuery("select * from flower");
while(rs.next()){
out.print("<center>");
out.print("<table style='width:770px;border-width:1px;border-style:dotted;font-size:14px;'>");
out.print("<tr>");
if(rs.getString("pictureb")!=null){ //没加if语句时可正常运行，加了之后提示 No data found
out.print("<td width='30%'>"+"<img src='picture/"+rs.getString("pictureb")+"'>");
}
out.print("<td width='70%'>");
out.print("<div style='font-weight:bold;font-size:medium;height:40px;line-height:40px;color:#000066; text-align:center;border-width:1px; border-style:solid; border-color:red;'>");
out.print(rs.getString("fname"));
out.print("</div>");
out.print("<div>");
out.print("材料："+rs.getString("cailiao"));
out.print("</div>");
out.print("<div>");
out.print("包装："+rs.getString("baozhuang"));
out.print("</div>");
out.print("<div>");
out.print("花语："+rs.getString("huayu"));
out.print("</div>");
out.print("<div>");
out.print("说明："+rs.getString("shuoming"));
out.print("</div>");
out.print("<div style='text-align:left; font-size: medium; color: #000066;text-decoration:line-through;margin-top:8px;'>");
out.print("原价："+rs.getString("price"));
out.print("</div>");
out.print("<div style='text-align:left; font-size: medium; color: #000066;'>");
out.print("现价：");
out.print("<font size ='33' color='red'>"+rs.getString("yourprice"));
out.print("</div>");
out.print("<div>");
out.print("<img src='image/ingwc_ico.jpg'>");
out.print("</div>");
out.print("</td>");

}

con.close();
}catch(SQLException e){
out.print(e);
}
%>
</body>
</html>
主要是if语句那里不明白为什么是错的，求解答谢谢！
错误提示如下：