iText PDF的矩形填充颜色

import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfWriter;

import java.io.FileOutputStream;
import java.io.IOException;

public class RectangleFillColorExample {
    public static void main(String[] args) {
        Document document = new Document();
        try {
            PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("rectangle_fill_color.pdf"));
            document.open();
            PdfContentByte contentByte = writer.getDirectContent();

            Rectangle rectangle = new Rectangle(100, 100, 200, 200);
            rectangle.setBackgroundColor(new BaseColor(255, 0, 0)); // 设置填充颜色为红色

            contentByte.rectangle(rectangle);
            contentByte.fill();

            document.close();
            writer.close();
        } catch (DocumentException | IOException e) {
            e.printStackTrace();
        }
    }
}