Sample Publisher: Flyfox
A database connection is the most important part of a dynamic web site, and the technology for connecting to the database in Java is JDBC (Java Database Connectivity). Many database systems have JDBC drivers, and Java programs connect to databases through JDBC drivers, execute queries, extract data, and so on. Sun also developed JDBC-ODBC Bridge, which allows Java programs to access databases with ODBC drivers, most of which currently have ODBC drivers, so Java programs can access Oracle, Sybase, MS SQL Server and MS Access, and so on. Here's how to implement a Dynamic FAQ (FAQ and Answer) Web site with access.
First, create an Access database (Faq.mdb), where the Design tables (table) FAQs, with the field ID (AutoIncrement, and set as the primary key), subject (type, length), Answers (memo type). This table can contain some common questions and answers about programming knowledge. See Figure 4.
Then, in the ODBC DataSource module of Control Panel, add system DSN, name FAQ, and point to Faq.mdb.
Create a Javabean,faq.java and save it in the \jswdk-1.0.1\webpages\web-inf\jsp\beans\test directory. The contents of Faq.java are as follows:
Package test;
Import java.sql.*;
public class FAQ {
String sdbdriver = "Sun.jdbc.odbc.JdbcOdbcDriver";
String sConnStr = "Jdbc:odbc:faq";
Connection conn = null;
ResultSet rs = null;
Public FAQ () {
try {
Class.forName (Sdbdriver);
}
catch (Java.lang.ClassNotFoundException e) {
System.err.println ("FAQ ():" + e.getmessage ());
}
}
Public ResultSet executequery (String sql) {
rs = null;
try {
conn = Drivermanager.getconnection (SCONNSTR);
Statement stmt = Conn.createstatement ();
rs = stmt.executequery (SQL);
}
catch (SQLException ex) {
System.err.println ("Aq.executequery:" + ex.getmessage ());
}
Return RS;
}
}
After compiling Faq.java with the method described in the previous section, create the JSP file faq.jsp under the \jswdk-1.0.1\webpages\test directory, as follows:
<meta http-equiv= "Content-type" content= "text/html; charset=gb2312 ">
<title> My FAQ!</title>
<body>
<p><b> this is my faq!</b></p>.
<%@ page language= "java" import= "java.sql.*"%>
<jsp:usebean id= "workm" scope= "page" class= "Test.faq"/>
<%
ResultSet RS = Workm.executequery ("SELECT * from FAQs");
String tt;
while (Rs.next ()) {
tt = rs.getstring ("Answer");
Out.print ("<LI>" + rs.getstring ("Subject") + "</LI>");
Out.print ("<pre>" + TT + "</pre>");
}
Rs.close ();
%>
