JSP Tag Library

1
JSP Tag Library

• CSCI 4300
• Notes from Steve Small,
• http//www.javaworld.com/javaworld/jw-02-2003/jw-0
  228-jstl.html

2
What is the Tag library?

• Creates additional XML-style tags
• Provide programming functionality with (somewhat)
  less mess
• Standard tag library
• Core functions (output, control statements)
• Formatting
• Internationalization
• SQL

3
Installing the standard library

• Download and install JSTL support in Tomcat
• Declare in web.xml
• lttaglibgt    lttaglib-urigthttp//java.sun.com/jstl/
  corelt/taglib-urigt    lttaglib-locationgt/WEB-INF/c.
  tldlt/taglib-locationgt  lt/taglibgt
• Include taglib descriptor file c.tld in WEB-INF
• lt_at_ taglib uri"http//java.sun.com/jstl/core"
  prefix"c" gt

4
Core STL Example

• ltbgtParameter values passed to this page for each
  parameter lt/bgt
• lttable border"2"gtltcforEach var"current"
  items"param"gt    lttrgt    lttdgt    ltbgtltcout
  value"current.key" /gtlt/bgt    lt/tdgt        ltc
  forEach var"aVal" items"paramValuescurrent.k
  ey"gt            lttdgt            ltcout
  value"aVal" /gt            lt/tdgt        lt/cf
  orEachgt    lt/trgtlt/cforEachgtlt/tablegt
• Param and paramValues are global Map vars from
  Web container

5
JSP Expression Language

• Similar to PHP or Perl string interpolation
• variable-name value of that variable
• ltcout value"anExpression"/gtltcout
  value"literalTextanExpressionanotherExpressi
  on"/gtltcout value"literalText"/gt
• anObject.aPropertyanObject"aPropertyName"
  anObjectaVariableContainingPropertyName