Using an Editor Pane to Display Text from a URL

One task that you can accomplish without knowing anything about the Swing text system is displaying text from a URL. Here's the code from TextSamplerDemo.java (in a .java source file) that creates an uneditable editor pane that displays text formatted with HTML tags:
JEditorPane editorPane = new JEditorPane();
editorPane.setEditable(false);
java.net.URL helpURL = TextSamplerDemo.class.getResource(
                                "TextSamplerDemoHelp.html");
if (helpURL != null) {
    try {
        editorPane.setPage(helpURL);
    } catch (IOException e) {
        System.err.println("Attempted to read a bad URL: " + helpURL);
    }
} else {
    System.err.println("Couldn't find file: TextSamplerDemoHelp.html");
}

//Put the editor pane in a scroll pane.
JScrollPane editorScrollPane = new JScrollPane(editorPane);
editorScrollPane.setVerticalScrollBarPolicy(
                JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
editorScrollPane.setPreferredSize(new Dimension(250, 145));
editorScrollPane.setMinimumSize(new Dimension(10, 10));
The code uses the default constructor to create the editor pane, then calls setEditable(false) so the user cannot edit the text. Next, the code creates the URL object, and calls the setPage method with it.

The setPage method opens the resource pointed to by the URL and figures out the format of the text (which in the example is HTML). If the text format is known, the editor pane initializes itself with the text found at the URL. A standard editor pane can understand plain text, HTML, and RTF. Note that the page might be loaded asynchronously, which keeps the GUI responsive but means that you shouldn't count on the data being completely loaded after the call to setPage returns.