HTML rendering : Java Glossary

In Applets

java.net.URL url = new java.net.URL ( "http://mindprod.com" );
getAppletContext().showDocument( url );

There are some catches:

• The URL (Uniform Resource Locator) must be absolute and must have a protocol e.g. http: or file:. Use getDocumentBase or getCodeBase and the URL context-constructor to make it absolute if you have a relative one. You must always have at least filename in your relative part.
• Older versions of Opera did not work showDocument if there is a trailing #XXXX on your URL.
• showDocument ignores the BASE TARGET of the current page. You must specify it explicitly as the second parameter to showDocument.

In Applications

• Unfortunately showDocument does not allow you to take a hunk of HTML you have in a String, perhaps as the result of a POST and display it. In that case you somehow have to persuade your server to put that html in a file where you can find it via URL. Alternatively you could use Oracle’s not-free HTML rendering classes.
• In Java version 1.2 there is javax.swing.text.HTMLEditorKit and javax.swing.text.HTMLEditorPane which offers primitive HTML 3.2 rendering ability, inching toward HTML 4 compatibility. It also supports surprising amount of CSS (Cascading Style Sheets). You use it like this:

  output = new JEditorPane();
  output.setContentType( "text/html" );
  output.setEditable( false );

  From then on text in the pane is rendered as HTML. You can also use

  output.setPage( "http://mindprod.com" );

  to render a page.
• Here is how you can render and URL pointing to an HTML page inside Java.
• In older JVM (Java Virtual Machine) s, if you are writing an application you are SOL. For applications, there is no standard HTML rendering class, though BISS-AWT has some primitive HTML rendering code.
• Flying Saucer is very rigid about standards. It will not render the typical crap you find on the web, only your own carefully validated markup.
• JDic Browser is a means to embed Gecko into your Java app, giving pretty much all the rendering engine you might need.

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