Rules concerning basic JSP guidelines.
Scripts should be part of Tag Libraries, rather than part of JSP pages.
This rule is defined by the following XPath expression:
// Element [ string:upper-case(@Name)="SCRIPT" and (@EndLine - @BeginLine > 10) ]
Here's an example of code that would trigger this rule:
<HTML> <BODY> <!--Java Script--> <SCRIPT language="JavaScript" type="text/javascript"> <!-- function calcDays(){ var date1 = document.getElementById('d1').lastChild.data; var date2 = document.getElementById('d2').lastChild.data; date1 = date1.split("-"); date2 = date2.split("-"); var sDate = new Date(date1[0]+"/"+date1[1]+"/"+date1[2]); var eDate = new Date(date2[0]+"/"+date2[1]+"/"+date2[2]); var daysApart = Math.abs(Math.round((sDate-eDate)/86400000)); document.getElementById('diffDays').lastChild.data = daysApart; } onload=calcDays; //--> </SCRIPT> </BODY> </HTML>
Scriptlets should be factored into Tag Libraries or JSP declarations, rather than being part of JSP pages.
This rule is defined by the following XPath expression:
//descendant::*[ self::JspScriptlet or (self::Element and string:upper-case(@Name)="JSP:SCRIPTLET") ]
Here's an example of code that would trigger this rule:
<HTML> <HEAD> <% response.setHeader("Pragma", "No-cache"); %> </HEAD> <BODY> <jsp:scriptlet>String title = "Hello world!";</jsp:scriptlet> </BODY> </HTML>
Style information should be put in CSS files, not in JSPs. Therefore, don't use <B> or <FONT> tags, or attributes like "align='center'"
This rule is defined by the following Java class: net.sourceforge.pmd.jsp.rules.NoInlineStyleInformation
Here's an example of code that would trigger this rule:
<html><body><p align='center'><b>text</b></p></body></html>
Do not use an attribute called 'class'. Use "styleclass" for CSS styles.
This rule is defined by the following XPath expression:
//Attribute[ string:upper-case(@Name)="CLASS" ]
Here's an example of code that would trigger this rule:
<HTML> <BODY> <P class="MajorHeading">Some text</P> </BODY> </HTML>
Do not do a forward from within a JSP file.
This rule is defined by the following XPath expression:
//Element[ @Name="jsp:forward" ]
Here's an example of code that would trigger this rule:
<jsp:forward page='UnderConstruction.jsp'/>
IFrames which are missing a src element can cause security information popups in IE if you are accessing the page through SSL. See http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q261188
This rule is defined by the following XPath expression:
//Element[string:upper-case(@Name)="IFRAME"][count(Attribute[string:upper-case(@Name)="SRC" ]) = 0]
Here's an example of code that would trigger this rule:
<HTML><title>bad example><BODY> <iframe></iframe> </BODY> </HTML> <HTML><title>good example><BODY> <iframe src="foo"></iframe> </BODY> </HTML>
In a production system, HTML comments increase the payload between the application server to the client, and serve little other purpose. Consider switching to JSP comments.
This rule is defined by the following XPath expression:
//CommentTag
Here's an example of code that would trigger this rule:
<HTML><title>bad example><BODY> <!-- HTML comment --> </BODY> </HTML> <HTML><title>good example><BODY> <%-- JSP comment --%> </BODY> </HTML>
Avoid duplicate import statements inside JSP's.
This rule is defined by the following Java class: net.sourceforge.pmd.jsp.rules.DuplicateJspImports
Here's an example of code that would trigger this rule:
<%@ page import=\"com.foo.MyClass,com.foo.MyClass\"%><html><body><b><img src=\"<%=Some.get()%>/foo\">xx</img>text</b></body></html>