Java如何在PDF中添加ToolTip工具提示

<repositories>
        <repository>
            <id>com.e-iceblue</id>
            <url>https://repo.e-iceblue.cn/repository/maven-public/</url>
        </repository>
    </repositories>
<dependencies>
    <dependency>
        <groupId>e-iceblue</groupId>
        <artifactId>spire.pdf.free</artifactId>
        <version>4.4.1</version>
    </dependency>
</dependencies>

import com.spire.pdf.*;
import com.spire.pdf.fields.PdfButtonField;
import com.spire.pdf.fields.PdfButtonLayoutMode;
import com.spire.pdf.general.find.PdfTextFind;

import java.awt.geom.Rectangle2D;

public class ToolTip {
    public static void main(String[] args) {
        //加载示例文档
        PdfDocument pdf = new PdfDocument();
        pdf.loadFromFile("test.pdf");

        //获取第2页并查找字符串,获取其位置
        PdfPageBase page = pdf.getPages().get(1);
        PdfTextFind[] result = page.findText("安装与反安装测试").getFinds();
        Rectangle2D rec = result[0].getBounds();

        //在搜索文本上添加不可见按钮
        PdfButtonField field1 = new PdfButtonField(page, "field1");
        field1.setBounds(rec);
        //设置工具提示文本及样式
        field1.setToolTip( "详见文末附件内容及使用手册！");
        field1.setBorderWidth(0);
        field1.setLayoutMode(PdfButtonLayoutMode.Icon_Only);
        field1.getIconLayout().isFitBounds();

        //保存文档
        pdf.saveToFile("Result.pdf", FileFormat.PDF);
        pdf.dispose();
    }
}