使用的版本是：
<dependency>
<groupId>org.docx4j</groupId>
<artifactId>docx4j</artifactId>
<version>6.1.2</version>
</dependency>
<dependency>
<groupId>org.glassfish.jaxb</groupId>
<artifactId>jaxb-runtime</artifactId>
<version>2.3.1</version>
</dependency>
代码
import org.docx4j.openpackaging.exceptions.Docx4JException;
import org.docx4j.openpackaging.packages.WordprocessingMLPackage;
import org.docx4j.wml.*;
private static void addPageBreak(WordprocessingMLPackage wordMLPackage) {
// 创建分页符元素
Br pageBreak = new Br();
pageBreak.setType(STBrType.PAGE);
// 创建段落和运行元素，并将分页符添加到运行元素
P paragraph = new P();
R run = new R();
run.getContent().add(pageBreak);
// 将运行元素添加到段落
paragraph.getContent().add(run);
// 将段落添加到文档末尾
wordMLPackage.getMainDocumentPart().getContent().add(paragraph);
}