在xml DOM方法中添加新标记有时会添加垃圾标记，文件在android中无用

Question

在android应用程序中，我将数据存储到xml文件中。我正在使用DOM方法在xml文件中添加新标签。有时它会添加一些垃圾标签，文件不再使用。这种行为的原因是什么？我读到DOM对于大尺寸文件来说很慢。最大文件大小约为800KB。是这个问题的原因吗？ 你能提供解决方案来避免这个问题吗？

<?xml version="1.0" encoding="UTF-8"?>
<MainCategory>
  <Type>Nos</Type>
  <Category>Briyani</Category>
  <CurrentStock>0.00</CurrentStock>
  <Purchased>
     <Items>
     <Date>01/12/2016</Date>
     <Quantity>116.00</Quantity>
     <ManualUpdate>Yes</ManualUpdate>
     <SourceDetails>NIL</SourceDetails>
     <Reason>None</Reason>
     </Items>
   </Purchased>
</MainCategory>

文件格式如上所示。购买的物品反复添加。 但有时候，作为垃圾和文件添加的结束标记（ nCategory＆gt; ）中的部分字符串无用，如下所示。

<?xml version="1.0" encoding="UTF-8"?>
<MainCategory>
  <Type>Nos</Type>
  <Category>Briyani</Category>
  <CurrentStock>0.00</CurrentStock>
  <Purchased>
     <Items>
     <Date>01/12/2016</Date>
     <Quantity>116.00</Quantity>
     <ManualUpdate>Yes</ManualUpdate>
     <SourceDetails>NIL</SourceDetails>
     <Reason>None</Reason>
     </Items>
   </Purchased>
</MainCategory>nCategory>

添加新标记代码如下：

try{
        String filepath = ctx.getFilesDir().getAbsolutePath()+"/"+XmlfileName;
        File inputFile = new File(filepath);

        DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
        Document doc = docBuilder.parse(inputFile);

        // Get the root element
        Node InvItems = doc.getFirstChild();
        NodeList list = InvItems.getChildNodes();

        for (int i = 0; i < list.getLength(); i++) {

            Node node = list.item(i);
            //Update Current Stock
            if ("CurrentStock".equals(node.getNodeName())) {
                node.setTextContent(CurrentStock);
            }
            if (PurOrUsedStr.equals(node.getNodeName())) {
                    // append a new node to staff
                    Element p1 = doc.createElement("Items");

                    Element date = doc.createElement("Date");
                    date.appendChild(doc.createTextNode(DateStr));
                    p1.appendChild(date);

                    Element quantity = doc.createElement("Quantity");
                    quantity.appendChild(doc.createTextNode(UpdateQuantity));
                    p1.appendChild(quantity);

                    Element AutoOrManual = doc.createElement("ManualUpdate");
                    AutoOrManual.appendChild(doc.createTextNode(AutoManuUpdate));
                    p1.appendChild(AutoOrManual);

                    Element SrcDetails = doc.createElement("SourceDetails");
                    SrcDetails.appendChild(doc.createTextNode(SourceDetails));
                    p1.appendChild(SrcDetails);

                    Element ReasonSplCmt = doc.createElement("Reason");
                    ReasonSplCmt.appendChild(doc.createTextNode(ReasonStr));
                    p1.appendChild(ReasonSplCmt);

                    Element UpdateTime = doc.createElement("UpdateTime");
                    UpdateTime.appendChild(doc.createTextNode(UpdateTimeStr));
                    p1.appendChild(UpdateTime);

                    node.appendChild(p1);

                    IsPurOrUsedTagAvail = true;
                }

        }
        // write the content into xml file
        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        Transformer transformer = transformerFactory.newTransformer();
        DOMSource source = new DOMSource(doc);
        //StreamResult result = new StreamResult(new File(filepath));
        StreamResult result = new StreamResult(new FileOutputStream(filepath));
        transformer.transform(source, result);

    } catch (ParserConfigurationException pce) {
        pce.printStackTrace();
        StatusStr = "Exception";
    }catch (TransformerException tfe) {
        StatusStr = "Exception";
        tfe.printStackTrace();
    } catch (IOException ioe) {
        StatusStr = "Exception";
        ioe.printStackTrace();
    } catch (SAXException sae) {
        StatusStr = "Exception";
        sae.printStackTrace();
    }