Servlet學習筆記(三)-----用HTML頁面訪問Servlet
1.使用者通過login.html頁面，輸入機票ID號就可以得到該航班的起飛城市和目的城市
2.login.html程式碼如下：
<HTML><?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
<HEAD>
<TITLE>Welcome to the online reservation system </TITLE>
</HEAD>
<BODY>
<CENTER>
<TABLE>
<FORM method=post action="http://127.0.0.1:8000/servletcontext/flightalias">
<TR>
<TD>Your ticket number ID here </td> <td><input type=text name=numid> </TD>
</TR>
<TR>
<TD>Your password here </td> <td><input type=text name=password> </TD>
</TR>
</TABLE>
<CENTER> <INPUT type=submit>
</FORM>
</CENTER>
</BODY>
</HTML>
注：servletcontext是Web Context, flightalias是Component Aliases
3.Servlet程式碼如下：（flight.java）
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import java.sql.*;
public class flight extends HttpServlet
{
Connection dbcon;
PreparedStatement s;
ResultSet result;
public void service(HttpServletRequest req, HttpServletResponse res)throws IOException
{
//連線資料庫
try
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
dbcon=DriverManager.getConnection("jdbc:odbc:MyDataSource","sa","");
}
catch(ClassNotFoundException e)
{
System.out.println("Database driver not found");
System.out.println(e.toString());
}
catch (Exception e)
{
System.out.println("UNKNOWN!?");
} // end catch
//boolean cookieFound = false;
boolean valuefound=false;
//Cookie thisCookie = null;
String numid=req.getParameter("numid");
String password=req.getParameter("password");
String fromCity,toCity;
fromCity=new String();
toCity=new String();
res.setContentType("text/html");
PrintWriter out = res.getWriter();
/*Cookie[] cookies = req.getCookies();
try
{
for(int I=0;I<cookies.length;I++)
{
System.out.println("Inside for");
thisCookie = cookies[I];
if(thisCookie.getName().equals("pnrnum"))
{
System.out.println("Cookie found");
cookieFound = true;
break;
}
}
}
catch(NullPointerException e)
{
cookieFound=false;
}*/
try
{
s=dbcon.prepareStatement("select * from Flight where numid=?");
s.setString(1,numid);
result=s.executeQuery();
if (result.next())
{
valuefound=true;
//System.out.println(result.getString(0));
}
else
{
valuefound=false;
} //end else
} // end try
catch(Exception e)
{
System.out.println(e.toString());
}
if (valuefound==true)
{
out.println("<HTML>");
out.println("<BODY>");
out.println("The booking details are as follows/n");
out.println("<table>");
try
{
try
{
fromCity=result.getString(2);
toCity=result.getString(3);
}
catch (Exception e)
{
System.out.println("Error");
System.out.println(e.toString());
}
out.println("<tr>");
out.println("<td>");
out.println("From City: ");
out.println("</td>");
out.println("<td>");
out.println(fromCity);
out.println("</td>");
out.println("</tr>");
out.println("<tr>");
out.println("<td>");
out.println("To City: ");
out.println("</td>");
out.println("<td>");
out.println(toCity);
out.println("</td>");
out.println("</tr>");
}
catch(Exception ev)
{
System.out.println("Error");
}
} // end if
if (valuefound==false)
{
out.println("The number ID that you have specified does not exist. ");
out.println("Please check if you have entered the correct number ID.");
} //end if
try
{
dbcon.close();
}
catch(Exception e)
{
System.out.println("Error closing database");
}
} // end service
}
