How to disable the automatic HTML support of JLabel?

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A Swing JLabel automatically interprets any text as HTML content, if it starts with . If the content of this HTML is an image with invalid URL this will cause th

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野的像风

2021-01-02 13:25

Hanging is probably the least unpleasant behavior. This is why Data Validation is so very important. Just do not allow the users to enter something like that.

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清酒与你

2021-01-02 13:31

There is a way if you create your own look and feel.
I'm not sure how well this performs is this, but it works. Lets assume you will extend the "Classic Windows" L&F.You need at leas 2 classes One is the Look&Feel itself, lets call it WindowsClassicLookAndFeelExt. You only need to override method initClassDefaults.

package testSwing;

import javax.swing.UIDefaults;
import com.sun.java.swing.plaf.windows.WindowsClassicLookAndFeel;

public class WindowsClassicLookAndFeelExt extends WindowsClassicLookAndFeel    {
    @Override protected void initClassDefaults(UIDefaults table){
        super.initClassDefaults(table);
        Object[] uiDefaults = { "LabelUI", WindowsLabelExtUI.class.getCanonicalName()};
        table.putDefaults(uiDefaults);
    }
}

You also need a WindowsLabelExtUI class to manage all JLabels and set the property:

package testSwing;
import javax.swing.JComponent;
import javax.swing.plaf.ComponentUI;
import com.sun.java.swing.plaf.windows.WindowsLabelUI;

public class WindowsLabelExtUI extends WindowsLabelUI{
    static WindowsLabelExtUI singleton = new WindowsLabelExtUI();

    public static ComponentUI createUI(JComponent c){
        c.putClientProperty("html.disable", Boolean.TRUE);    
        return singleton;
    }
}

And finally a test class when you set the theme as WindowsClassicLookAndFeelExt

package testSwing;

import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.UIManager;


public class Main{
    public static void main(String[] args){
        try{                UIManager.setLookAndFeel(WindowsClassicLookAndFeelExt.class.getCanonicalName());
        }catch (Exception e){
            e.printStackTrace();
        }

        JFrame frame = new JFrame("JList Test");
        frame.setLayout(new FlowLayout());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        String[] selections = {"<html><img src='http:\\\\invalid\\url'>", "<html><H1>Hello</h1></html>", "orange", "dark blue"};

        JList list = new JList(selections);

        list.setSelectedIndex(1);
        System.out.println(list.getSelectedValue());

        JLabel jLabel = new JLabel("<html><h2>standard Label</h2></html>");
        frame.add(new JScrollPane(list));
        frame.add(jLabel);
        frame.pack();

        frame.setVisible(true);
    }
}

And you will see something like

alt text

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误落风尘

2021-01-02 13:40

For a simple JLabel, you can call the JComponent method

myLabel.putClientProperty("html.disable", Boolean.TRUE);

on the label where you want to disable HTML rendering.

Reference: Impossible to disable HTML Rendering in a JLabel

For something like a JTable, JTree, or JList you'll need to create a custom cell renderer that sets this property. Here's an example (modified from this example) that creates a custom cell renderer for a JList.

import java.awt.Component;
import java.awt.FlowLayout;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.ListCellRenderer;

public class JListTest {
    public static void main(String[] args) {
        JFrame.setDefaultLookAndFeelDecorated(true);
        JFrame frame = new JFrame("JList Test");
        frame.setLayout(new FlowLayout());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        String[] selections = { "<html><img src='http:\\\\invalid\\url'>",
                "red", "orange", "dark blue" };
        JList list = new JList(selections);

        // set the list cell renderer to the custom class defined below
        list.setCellRenderer(new MyCellRenderer());

        list.setSelectedIndex(1);
        System.out.println(list.getSelectedValue());
        frame.add(new JScrollPane(list));
        frame.pack();

        frame.setVisible(true);
    }
}


class MyCellRenderer extends JLabel implements ListCellRenderer {
    public MyCellRenderer() {
        setOpaque(true);
        putClientProperty("html.disable", Boolean.TRUE);
    }

    public Component getListCellRendererComponent(
        JList list,
        Object value,
        int index,
        boolean isSelected,
        boolean cellHasFocus)
    {
        setText(value.toString());
        return this;
    }
}

I used the example code from the ListCellRenderer documentation as a starting point for the custom list cell renderer.

When I run the example, you can see that the HTML in the first list entry is rendered instead of being interpreted.

JList Custom Renderer

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