Supported JSP Version 1.1 subsets

This section lists and describes the directives, implicit objects, scripting elements, and standard actions included in DB2 Everyplace JSP support.

Directives

Page directive

Description

The page directive defines page-dependent attributes.

Syntax

<%@ page page_directive_attr_list %>
page_directive_attr_list ::= 
{language="scriptingLanguage"}
{extends="className" }
{import="importList" }
{contentType="ctinfo" }

Attributes

The four valid attributes for this directive are:

• language - Must be 'java' if specified.
• extends - A fully qualified Java programming language class name that names the superclass of the class to which this JSP page is transformed.
• import - The default import list is com.ibm.db2e.jsp.server.*, java.io.*, java.sql.*, and java.util.*.
• contentType - Can be any value (such as text/html, text/xml, application/x-octet).

Example

<%@ page contentType="text/html" %>

Include directive

Description

Use the include directive to include data in a JSP page. The included file may have elements which will also be processed.

Syntax

<%@ include file="relativeURLspec" %>

Attributes

The attribute for this directive is file which must be a page-relative path. The path cannot not start with a "/", and is to be interpreted relative to the current JSP page.

Example

<%@ include file="copyright.html" %>

Implicit objects

When you create JSP pages, you have access to certain implicit objects. They can be used within scriptlets and expressions, without first being declared. Each implicit object has a class defined in a core Java technology or com.ibm.db2e.jsp.server package, shown in Tabelle 13.

Tabelle 13. Implicit objects

java.lang.String getParameter(java.lang.String name)
java.lang.String getQueryString() 

java.lang.String encodeURL(java.lang.String url)
 void setDateHeader(java.lang.String name, long date)
 void setHeader(java.lang.String name, java.lang.String value) 

java.lang.String getInitParameter(java.lang.String name)

Anmerkung:

Some of the types for the implicit objects above differ from those in JSP 1.1 due to the implementation of DB2 Everyplace JSP support.

Scripting elements

Declarations

Description

Use declarations to declare Java variables and methods used in a JSP page. Declarations are member variables (fields and methods) of the Java class for the JSP page.

Syntax

<%!declaration(s) %>

Example

<%!
String name = "Joe Smith";
 
public String getName() {
	return name;
} 
%>

Standard actions

<jsp:useBean>

Description

A jsp:useBean action associates an instance of a Java programming language object defined within the "page" scope available with a given id via a newly declared scripting variable of the same id.

Syntax

<jsp:useBean id="name" scope="page|request|session|application" typeSpec/>
typeSpec ::=
class="className"

Attributes

The three attributes for this tag are:

• id - Specifies the identifier of this bean. Do not reuse this name in the JSP page. This attribute is required
• scope - This attribute is ignored if specified. The default scope "page" is used.
• class - Specifies the class that this bean represents. This attribute is required.

Example

<jsp:useBean id="masterViewDBBean" class="Query1HTMLResultsMasterViewBean" />

<jsp:setProperty>

Description

The jsp:setProperty action sets the value of properties in a Bean.

Syntax

<jsp:setProperty name="beanName" prop_expr />
prop_expr ::=
property="propertyName" value="propertyValue"
propertyValue ::= string
The value propertyValue can also be a request-time attribute value.
propertyValue ::= expr_scriptlet

Attributes

The three attributes for this tag are:

• name - The name of a Bean instance defined by a <jsp:useBean> element before this action appears. The Bean instance must contain the property you want to set. This attribute is required.
• property - The name of the Bean property whose value you want to set. This attribute is required.
• value - The value to assign to the given property. This attribute can accept a request-time attribute expression as a value. This attribute is required.

Example

<jsp:setProperty name="masterViewDBBean" property="username" 
value='<%=config.getInitParameter("username")%>' />

Scriptlets

Description

Use scriptlets to hold any valid Java code fragments. These code fragments are placed in the source code for the JSP page, and are relative to other elements of the JSP page.

Syntax

<% scriptlet %>

Example

<% 
try { 
String name = Query1DBBean.getString(1);
out.println("Name = " + name); 
} 
catch (SQLException e) { 
 
} 
%>

Expressions

Description

Expressions are string representations of data types. You can use expressions in queries and in HTML comments. The application evaluates the expressions at run-time and converts the expressions into strings.

Syntax

<%= expression %>

Example

<%= new java.util.Date() %>

Note: Variable names that begin with __db2ejsp__ are keywords and are used internally. Do not use these variables in the JSP page.

Zugehörige Konzepte

• DB2 Everyplace JSP support overview
• Developing DB2 Everyplace JSP applications
• The sample JSP applications

Zugehörige Tasks

• Verifying JSP support on a Windows workstation
• Setting up for JSP development on a Windows CE device

Zugehörige Referenzen

• IBM custom tags for JSP application database access