JavaServer Pages, 3rd Edition

Escape Characters

Because certain character sequences are used to represent start and stop tags, you sometimes need to escape a character so the container doesn’t interpret it as part of a special character sequence.

In a scripting element, if you need to use the characters %> literally, you must escape the greater-than character with a backslash:

<% String msg = "Literal %\> must be escaped"; %>

To avoid the character sequence <% in template text to be interpreted as the start of a scripting element, you must escape the percent sign:

This is template text and <\% is not a start of a scriptlet.

Similarly, the dollar sign that start an EL expression must be escaped in a page where EL evaluation is enabled:

This is template text and \${this is not an EL expression}.

In an attribute value, you must use the following escapes:

attr='a value with an escaped \' single quote'
attr="a value with an escaped \" double quote"
attr="a value with an escaped \\ backslash"
attr="a value with an escaped %\> scripting end tag"
attr="a value with an escaped <\% scripting start tag"
attr="a value with an escaped \$ dollar sign"

As an alternative to escaping quote characters, you can use the ' and " character entities.