MySQL Database Connectivity with JSP (Windows)
A tutorial on how to get started with JavaServer pages using Sun's Tomcat web server (a Jakarta variant) and connecting to a MySQL database to retrieve data. Provided as a jumpstart for practicing with real-world applications. Tutorial is intended for users who may have had previous web/database experience but would like to get their feet wet in JSP. (Updated October 04, 2002)
AI
AI-sammanfattning: This codebase represents a historical implementation of the logic described in the metadata. Our preservation engine analyzes the structure to provide context for modern developers.
Källkod
<br><p><font face="Arial" size="2"><font face="Times New Roman" size="3">This
tutorial will show you how to connect to a MySQL database using JSP (JavaServer
Pages) under Windows and Tomcat web server. If you run into problems or find
errors, please let me know so I can fine-tune this document. This document will
probably be most useful for those who have done web scripting with MySQL
databases before but would like to get started with JSP/Servlets programming.
Database connectivity provides a good foundation for learning any new language,
as you can practice making real-world applications in a database environment.</font><font face="Times New Roman">
</font></p>
<p><b><font face="Arial, Helvetica" size="2">Requirements:</font></b></p>
<ol>
<li><font face="Times New Roman" size="3">MySQL<br>
<a href="http://www.mysql.com" target="_blank">http://www.mysql.com</a></font>
</li>
<li><font face="Times New Roman" size="3">Tomcat - version 4.1.12 Standard
used for this tutorial<br>
<a href="http://jakarta.apache.org/site/binindex.html" target="_blank">
http://jakarta.apache.org/site/binindex.html</a></font> </li>
<li><font face="Times New Roman" size="3">Java 2 JRE - version 1.4.1 used for
this tutorial<br>
<a href="http://java.sun.com/j2se/1.4.1/download.html">
http://java.sun.com/j2se/1.4.1/download.html</a></font> </li>
<li><font face="Times New Roman">MySQL Connector/J</font><font face="Times New Roman" size="3">
- version 2 used for this tutorial<br>
<a href="http://www.mysql.com/downloads/api-jdbc.html">
http://www.mysql.com/downloads/api-jdbc.html</a></font> </li>
</ol>
<p><b><font face="Arial, Helvetica" size="2">Assumptions:</font></b></p>
<ol>
<li><font face="Times New Roman" size="3">It is assumed that you already have
a MySQL database installed and a table to pull data from.</font> </li>
<li><font face="Times New Roman" size="3">It assumes you understand SQL, and
probably have done some web/database scripting with other languages.</font>
</li>
<li><font face="Times New Roman" size="3">The author uses the folder C:\Tomcat
as the folder where Tomcat will be extracted, however, you can place the
distribution files anywhere you wish.</font> </li>
<li><font face="Times New Roman" size="3">You know the basics of programming
Java. If you do not, I <b>highly</b> recommend you check out Sun's
<a href="http://java.sun.com/docs/books/tutorial/" target="_blank">Java
Tutorial</a>. </font> </li>
</ol>
<p><b><font face="Arial, Helvetica" size="3">Section A - Installation</font></b></p>
<ol>
<li><font face="Times New Roman" size="3">Install the Java 2 JRE. I put mine
in </font><font face="Courier New" size="2">C:\java\jre</font><font face="Times New Roman" size="3">,
which will be used in this tutorial, but you can put your anywhere you like. </font>
</li>
<li><font face="Times New Roman" size="3">Extract the Tomcat distribution
files to a folder. The default is </font><font face="Courier New" size="2">
jakarta-tomcat-4.1.12</font><font face="Times New Roman" size="3">, but I
chose to put the files in </font><font face="Courier New" size="2">C:\Tomcat</font><font face="Times New Roman" size="3">.</font>
</li>
<li><font face="Times New Roman" size="3">Copy the MySQL Connector JAR file to
the </font><font face="Courier New" size="2">C:\Tomcat\common\lib</font><font face="Times New Roman" size="3">
folder (ie, mysql-connector-java-2.0.14.jar).</font> </li>
</ol>
<p><font face="Arial, Helvetica" size="3"><b>Section B - Environmental Variables</b></font></p>
<p><font face="Times New Roman" size="3">Add the following environmental
variables to Windows:</font></p>
<div align="left">
<table border="0">
<tr>
<td width="30"> </td>
<td><font face="Courier New" size="2">JAVA_HOME=C:\java\jre<br>
TOMCAT_HOME=C:\Tomcat</font></td>
</tr>
</table>
</div>
<p><font face="Times New Roman" size="3">You can set environmental variables in
Windows 2000/XP by going to:<br>
Righy-click My Computer -> Properties -> Advanced -> Environmental Variables</font></p>
<p><font face="Times New Roman" size="3">You can set environmental variables in
Windows NT 4 by going to:<br>
Righy-click My Computer -> Properties -> Environment </font></p>
<p><b><font face="Arial, Helvetica" size="3">Section C - Working with Tomcat</font></b></p>
<p align="left"><font face="Times New Roman" size="3">To start the server,
execute </font><font face="Courier New" size="2">startup.bat</font><font face="Times New Roman" size="3">.
To stop the server, execute </font><font face="Courier New" size="2">
shutdown.bat </font><font face="Times New Roman" size="3">in the </font>
<font face="Courier New" size="2">C:\Tomcat\bin</font><font face="Times New Roman" size="3">
folder.</font></p>
<p><font face="Times New Roman" size="3">By default, the Tomcat web server is
access at this URL:<br>
</font><a href="http://localhost:8080/"><font face="Times New Roman" size="3">
http://localhost:8080/</font></a></p>
<p><font face="Times New Roman" size="3">The root folder of the server is
located in:</font><br>
<font face="Courier New" size="2">C:\Tomcat\webapps\ROOT</font></p>
<p><font face="Times New Roman" size="3">The root and default port can be
changed in this file:</font><br>
<font face="Courier New" size="2">C:\Tomcat\conf\server.xml</font></p>
<p><font face="Arial, Helvetica" size="3"><b>Section D - Write Your Code!</b></font></p>
<p><font face="Times New Roman" size="3">You can now start writing your JSP
scripts. Save it in a file with a JSP extension and place it in the ROOT
folder. I have provided a simple JSP script that demonstrates how to connect to
a list data from a MySQL database.</font></p>
<font color="#ff0000" size="2"><b>
<p><font face="Courier New"><%</font></b></font><font face="Courier New"><font size="2">@
page import=</font><font color="#0000f0" size="2">"java.sql.*"</font><font size="2">
<b>%></b></font><font color="#ff0000" size="2"><b><br>
<%</b></font><font size="2"><br>
String connectionURL = </font><font color="#0000f0" size="2">"jdbc:mysql://localhost:3306/mydatabase?user=;password="</font><font size="2">;<br>
Connection connection = </font><font color="#800000" size="2"><b>null</b></font><font size="2">;<br>
Statement statement = </font><font color="#800000" size="2"><b>null</b></font><font size="2">;<br>
ResultSet rs = </font><font color="#800000" size="2"><b>null</b></font><font size="2">;<br>
</font></font><font color="#ff0000" size="2"><b><font face="Courier New">%></font></p>
</b></font>
<p><font face="Courier New" color="#0000c0" size="2"><html><body></font></p>
<b><font color="#ff0000" size="2">
<p><font face="Courier New"><%</font></font><font face="Courier New" size="2"><br>
Class</font></b><font face="Courier New"><font size="2">.forName(</font><font color="#0000f0" size="2">"com.mysql.jdbc.Driver"</font><font size="2">).newInstance();<br>
connection = DriverManager.getConnection(connectionURL, </font>
<font color="#0000f0" size="2">""</font><font size="2">, </font>
<font color="#0000f0" size="2">""</font><font size="2">);<br>
statement = connection.createStatement();<br>
rs = statement.executeQuery(</font><font color="#0000f0" size="2">"SELECT * FROM
mytable"</font><font size="2">);</font></font></p>
<p><font face="Courier New"><font size="2"><b>while</b> (rs.next()) {<br>
out.println(rs.getString(</font><font color="#0000f0" size="2">"myfield"</font><font size="2">)+</font><font color="#0000f0" size="2">"<br>"</font><font size="2">);<br>
}</font></font></p>
<p><font face="Courier New" size="2">rs.close();</font><font color="#ff0000" size="2"><b><font face="Courier New"><br>
%></font></p>
</b></font>
<p><font face="Courier New" color="#0000c0" size="2"></body></html></font></p>
<p> <br>
<font face="Times New Roman" size="3">Obviously, you will want to change the <i>
username</i> and <i>password</i> to match your database. Also, the <i>
mydatabase</i> value in the connectionURL represents the name of the MySQL
database. Change appropriately. Finally, change the <i>mytable </i>and <i>
myfield</i> values in the script to match a table and field that exist within
your database. If the public is granted access to the database, you can use
this as your connectionURL:</font></p>
<p><font face="Courier New"><font size="2">String connectionURL = </font>
<font color="#0000f0" size="2">"jdbc:mysql://localhost:3306/mydatabase"</font><font size="2">;</font></font></p>
<p><font face="Times New Roman" size="3">Happy coding!</font></p>
</font>
Upload
Originalkommentarer (3)
Återställd från Wayback Machine