如何为ArrayList列表项中的单个单词设置不同颜色？

Hey there! Sounds like you need to display an ArrayList item ("Some important words") where only the word "important" is colored differently. Since an ArrayList itself is just a data storage structure, I assume you're working with a Swing JList (the common way to display ArrayList items in a UI). Here's a straightforward solution:

Step 1: Set up your ArrayList and JList #

First, define your ArrayList with the text, then create a JList to display it:

import java.util.ArrayList;
import javax.swing.JList;

// Initialize your ArrayList
ArrayList<String> listData = new ArrayList<>();
listData.add("Some important words");

// Create JList from the ArrayList
JList<String> itemList = new JList<>(listData.toArray(new String[0]));

Step 2: Create a Custom Cell Renderer #

To color part of the text, you'll need a custom ListCellRenderer that modifies how each list item is drawn. The easiest way is to use HTML in a JLabel (since Swing's JLabel supports basic HTML styling):

import javax.swing.DefaultListCellRenderer;
import javax.swing.JComponent;
import java.awt.Component;

class ColoredWordRenderer extends DefaultListCellRenderer {
    @Override
    public Component getListCellRendererComponent(JList<?> list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
        // Call the super method to handle default styling (selection colors, etc.)
        super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
        
        // Check if the value is a string, then modify the text
        if (value instanceof String itemText) {
            // Replace "important" with a colored HTML span
            String styledText = itemText.replace(
                "important", 
                "<span style='color: #ff4444;'>important</span>"
            );
            // Wrap the text in HTML tags to enable styling
            setText("<html>" + styledText + "</html>");
        }
        
        return this;
    }
}

Step 3: Attach the Renderer to Your JList #

Finally, set the custom renderer on your JList:

itemList.setCellRenderer(new ColoredWordRenderer());

Extra Tips #

• Change the Color: Swap #ff4444 (a red shade) with any valid CSS color name or hex code (like blue, #00cc66 for green).
• Multiple Occurrences: The replace() method will color every instance of "important" in the string—perfect if you have items with the word repeated.
• No HTML Alternative: If you don't want to use HTML, you could use a JTextPane as the renderer component, but that adds more complexity for simple color changes.

内容的提问来源于stack exchange，提问作者Vladimir Gusev