Java Network Programming (3rd ed) [Electronic resources] نسخه متنی

Chapter 8. HTML in Swing

As anyone who has ever
tried to write code to read HTML can tell you, it's
a painful experience. The problem is that although there is an HTML
specification, no web designer or browser vendor actually follows it.
And the specification itself is extremely loose. Element names may be
uppercase, lowercase, or mixed case. Attribute values may or may not
be quoted. If they are quoted, either single or double quotes may be
used. The < sign may be escaped as
&lt; or it may just be left raw in the file.
The <P> tag may be used to begin or end a
paragraph. Closing </P>,
</LI>, and </TD>
tags may or may not be used. Tags may or may not overlap. There are
just too many different ways of doing the same thing to make parsing
HTML an easy task. In fact, the difficulties encountered in parsing
real-world HTML were one of the prime motivators for the invention of
the much stricter XML, in which what is and is not allowed is
precisely specified and all browsers are strictly prohibited from
accepting documents that don't measure up to the
standard (as opposed to HTML, where most browsers try to fix up bad
HTML, thereby leading to the proliferation of nonconformant HTML on
the Web, which all browsers must then try to parse).

Fortunately,
as of JFC 1.1.1 (included in Java 1.2.2 and later), Sun provides
classes for basic HTML parsing and display that shield Java
programmers from most of the tribulations of working with raw HTML.
The javax.swing.textl.parser package can read
HTML documents in more or less their full, nonstandard atrocity,
while the javax.swing.textl package can render
basic HTML in JFC-based applications.