docx4j可以往文档中插入段落，使用起来和往List中插入元素一样，只要注意下下标位置就可以了，如第一次往下标5的地方插入段落后，模板中下标为8的变成了下标9。
举个例子,模板如下：
往模板中插入段落和表格
String inputfilepath = "e:/test_tmp/0904/test_p.docx";
WordprocessingMLPackage wordMLPackage = WordprocessingMLPackage.load(new java.io.File(inputfilepath));
MainDocumentPart documentPart = wordMLPackage.getMainDocumentPart();
String titleStr = "测试插入段落";
P p = Docx4j_Helper.factory.createP();
String rprStr = "<w:rPr xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:rFonts w:hint=\"eastAsia\" w:ascii=\"Times New Roman\" w:hAnsi=\"Times New Roman\" w:eastAsia=\"宋体\"/><w:b/><w:color w:val=\"333333\"/><w:sz w:val=\"32\"/><w:szCs w:val=\"32\"/></w:rPr>";
RPr rpr = (RPr) XmlUtils.unmarshalString(rprStr);
setParagraphContent(p, rpr, titleStr);
documentPart.getContent().add(5, p);
String tblPrStr = "<w:tblPr xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:tblW w:w=\"8522\" w:type=\"dxa\"/><w:tblBorders><w:top w:val=\"single\" w:sz=\"4\" w:space=\"0\"/><w:left w:val=\"single\" w:sz=\"4\" w:space=\"0\"/><w:bottom w:val=\"single\" w:sz=\"4\" w:space=\"0\"/><w:right w:val=\"single\" w:sz=\"4\" w:space=\"0\"/><w:insideH w:val=\"single\" w:sz=\"4\" w:space=\"0\"/></w:tblBorders></w:tblPr>";
Tbl tbl = Docx4j_Helper.factory.createTbl();
TblPr tblPr = (TblPr) XmlUtils.unmarshalString(tblPrStr);
tbl.setTblPr(tblPr);
Tr tr = Docx4j_Helper.factory.createTr();
Tc tc = Docx4j_Helper.factory.createTc();
tr.getContent().add(tc);
tc = Docx4j_Helper.factory.createTc();
tr.getContent().add(tc);
tc = Docx4j_Helper.factory.createTc();
tr.getContent().add(tc);
tc = Docx4j_Helper.factory.createTc();
tr.getContent().add(tc);
tc = Docx4j_Helper.factory.createTc();
tr.getContent().add(tc);
tbl.getContent().add(tr);
tr = Docx4j_Helper.factory.createTr();
tc = Docx4j_Helper.factory.createTc();
tr.getContent().add(tc);
tc = Docx4j_Helper.factory.createTc();
tr.getContent().add(tc);
tc = Docx4j_Helper.factory.createTc();
tr.getContent().add(tc);
tc = Docx4j_Helper.factory.createTc();
tr.getContent().add(tc);
tc = Docx4j_Helper.factory.createTc();
tr.getContent().add(tc);
tbl.getContent().add(tr);
documentPart.getContent().add(9, tbl);
Docx4j_Helper.saveWordPackage(wordMLPackage, outputfilepath);
结果为：
全文完。