无法在DOM XML文档中添加、删除节点

无法在DOM XML文档中添加、删除节点,xml,xml-parsing,Xml,Xml Parsing,实际上,我正在为下面的XML字符串编写XML DOM解析器 <?xml version="1.0" encoding="UTF-8"?> <schema version="1.0"> <itemGroups> <itemGroup id="itemGroup1"> <items> <item id="One" /> <item id="Two" />

实际上,我正在为下面的XML字符串编写XML DOM解析器

<?xml version="1.0" encoding="UTF-8"?>
<schema version="1.0">
  <itemGroups>
    <itemGroup id="itemGroup1">
      <items>
        <item id="One" />
        <item id="Two" />
        <item id="item1" />
        <item id="item1" />
        <item id="item1" />
        <item id="item1" />
      </items>
    </itemGroup>
    <itemGroup id="itemGroup2">
      <items>
        <item id="One" />
        <item id="Two" />
        <item id="item1" />
        <item id="item1" />
        <item id="item1" />
        <item id="item1" />
      </items>
    </itemGroup>
  </itemGroups> 
</schema>

在这里,我需要从每个项目组中删除id为“item”的项目。请帮助我仅使用文档对象来完成此操作

这是我们用来删除元素但得到空指针异常的代码

public static Document removeElement(Document doc, String idValue,
            String groupNode, String itemNode) {
        NodeList itemGroupList = doc.getElementsByTagName(groupNode);
        for (int i = 0; i < itemGroupList.getLength(); i++) {
            Element node = (Element) itemGroupList.item(i);
            if (node.getAttribute("id").equals(idValue)) {
                NodeList itemlist = node.getElementsByTagName(itemNode);
                for (int j = 0; j < itemlist.getLength(); j++) {
                    Element nodenewitm = (Element) itemlist.item(j);
                    NodeList nodeListRemove = nodenewitm.getElementsByTagName("item");
                    if(nodenewitm != null) {
                        NodeList itemsList = nodenewitm.getChildNodes();
                        if(itemsList != null) {
                            for (int counter = 0; counter < itemsList.getLength(); counter++) {
                                Element item = (Element) itemlist.item(counter);
                                if(item.getAttribute("id").indexOf("ATTR_") > 0) {
                                    nodenewitm.removeChild(item);
                                }
                            }
                        }
                    }
                }
            }
        }
        return doc;
    }
publicstaticdocumentremovelement(documentdoc,stringidvalue,
字符串组节点,字符串项节点){
NodeList itemGroupList=doc.getElementsByTagName(groupNode);
对于(int i=0;i0){
移除儿童(项目);
}
}
}
}
}
}
}
退货单;
}
我们只是调用removelement(文档,“itemGroup1”、“itemGroup”、“items”)

如果我能尽快得到帮助,我将不胜感激

谢谢
Ramesh Reddy使用XPath。您可以根据需要构造表达式

void removeElement(Document doc)
        throws XPathExpressionException {
    XPath xp = XPathFactory.newInstance().newXPath();

    NodeList nl = (NodeList) xp.evaluate(
            "//items/item[starts-with(@id, 'item')]", doc,
            XPathConstants.NODESET);
    for (int i = 0; i < nl.getLength(); ++i) {
        nl.item(i).getParentNode().removeChild(nl.item(i));
    }
}
void removelement(文档文档)
抛出XPathExpressionException{
XPath xp=XPathFactory.newInstance().newXPath();
NodeList nl=(NodeList)xp.evaluate(
//items/item[以(@id,'item')]开头],doc,
XPathConstants.NODESET);
对于(int i=0;i