|
The code for the JSP
The code for the JSP starts with a scriptlet that contains Java
code that retrieves two attributes from the session object:
<!doctype html public "-//W3C//DTD HTML 4.0 Transitional//EN">
<%
String sqlStatement =
(String) session.getAttribute("sqlStatement");
if (sqlStatement == null)
sqlStatement = "";
String message =
(String) session.getAttribute("message");
if (message == null)
message = "";
%>
The first attribute is the string that contains the SQL
statement, and the second attribute is the string that contains
the result message. If these attributes contain null values,
they haven't been set yet so this code sets the sqlStatement and
message variables to empty strings.
This JSP also contains an HTML form that contains a text area
and a submit button:
<form action="../servlet/murach.sql.SQLGatewayServlet" method="post">
<b>SQL statement:</b><br>
<textarea name="sqlStatement" cols=60 rows=8>
<%= sqlStatement %>
<textarea><br>
<br>
<input type="submit" value="Execute">
<form>
Here, the text area allows the user to enter the SQL statement.
This code creates a text area that's approximately 60 characters
wide and 8 lines tall. Within this area, the sqlStatement
variable is displayed, which is empty the first time this JSP is
run. Then, when the user clicks the submit button, this JSP
calls the SQLGatewayServlet that's described later in this
article.
The table near the end of the JSP displays the message string
that contains the result of the SQL statement:
SQL result:
<table cellpadding="5" border="1">
<%= message %>
<table>
Since this message contains the rows and columns for an HTML
table, it's coded within the Table tags.
New on the Java Boutique:
New Review:
Time Management Made Easy with the Quartz Enterprise Job Scheduler
Why not just use the Java timer API? This open source scheduling
API boasts simplicity, ease-of-integration, a well-rounded feature
set, and it's free!
New Applet:
Reverse Complement
Reverse Complement is a simple applet that converts DNA or RNA
sequences into three useful formats.
Elsewhere on internet.com:
WebDeveloper Java
Lots of Java information on webdeveloper.com
WDVL Java
Thorough Java resource at the Web Developer's Virtual Library.
ScriptSearch Java
Hundreds of free Java code files to download.
jGuru: Your View of the Java Universe
Customizable portal with online training, FAQs, regular news updates, and tutorials.
|