如何使用JAVA將XML字符串添加到現有XML文件中？

Question

我有名為temp.xml的xml文件，內容如下。

<?xml version="1.0" encoding="UTF-8" standalone="no"?><combinedstaff>
<staff><firstname>added firstname</firstname><lastname>added lastname</lastname><nickname>added nickname</nickname><salary>$10,000</salary></staff></combinedstaff>

我有這種方式的xml字符串，

String sampleXML="<staff><firstname>fff</firstname><lastname>lll</lastname><nickname>nnn</nickname><salary>$20,000</salary></staff>";

我需要將此xml字符串附加到上面的xml文件中，以便最終的xml應該看起來像這樣，

<?xml version="1.0" encoding="UTF-8" standalone="no"?><combinedstaff>
<staff><firstname>added firstname</firstname><lastname>added lastname</lastname><nickname>added nickname</nickname><salary>$10,000</salary></staff>
<staff><firstname>fff</firstname><lastname>lll</lastname><nickname>nnn</nickname><salary>$20,000</salary></staff>
</combinedstaff>

我已經用這種方式編碼，但是我得到了一些垃圾字符，例如;< 以這種方式添加到xml字符串中，

<?xml version="1.0" encoding="UTF-8" standalone="no"?><combinedstaff>
<staff><firstname>added firstname</firstname><lastname>added lastname</lastname><nickname>added nickname</nickname><salary>$10,000</salary></staff><staff>&lt;staff&gt;&lt;firstname&gt;added firstname&lt;/firstname&gt;&lt;lastname&gt;added lastname&lt;/lastname&gt;&lt;nickname&gt;added nickname&lt;/nickname&gt;&lt;salary&gt;$10,000&lt;/salary&gt;&lt;/staff&gt;</staff><staff>&lt;staff&gt;&lt;firstname&gt;added firstname&lt;/firstname&gt;&lt;lastname&gt;added lastname&lt;/lastname&gt;&lt;nickname&gt;added nickname&lt;/nickname&gt;&lt;salary&gt;$10,000&lt;/salary&gt;&lt;/staff&gt;</staff><staff>&lt;staff&gt;&lt;firstname&gt;added firstname&lt;/firstname&gt;&lt;lastname&gt;added lastname&lt;/lastname&gt;&lt;nickname&gt;added nickname&lt;/nickname&gt;&lt;salary&gt;$10,000&lt;/salary&gt;&lt;/staff&gt;</staff></combinedstaff>

這是我的代碼，

public class writexml1 {

    public static void main (String args[]) 
    {

        File docFile = new File(".xml");

        Document doc = null;
        try 
        {
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            doc = db.parse(docFile);
        } 
        catch (java.io.IOException e) 
        {
            System.out.println("Can't find the file");
        } 
        catch (Exception e) 
        {
            System.out.print("Problem parsing the file.");
        }

        Element root = doc.getDocumentElement();

        System.out.println("The root element is " + root.getNodeName() + ".\n");

        NodeList children = root.getChildNodes();
        System.out.print("There are "+children.getLength()+" child elements.\n");
        System.out.print("They are: \n");


        Element staffElement = doc.createElement("staff");

        Node updateText = doc.createTextNode("<firstname>added firstname</firstname><lastname>added lastname</lastname><nickname>added nickname</nickname><salary>$10,000</salary></staff>");
        staffElement.appendChild(updateText);

        root.appendChild(staffElement);

        try{
            String outputURL = "temp.xml";

            DOMSource source = new DOMSource(doc);
            StreamResult result = new StreamResult(new FileOutputStream(outputURL));

            TransformerFactory transFactory = TransformerFactory.newInstance();
            Transformer transformer = transFactory.newTransformer();

            transformer.transform(source, result);

        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

我該如何解決這個問題？ 問題出在哪里？

有人可以幫忙嗎？

Answer 1

不要將嵌套元素添加為文本。

該行：

Node updateText = doc.createTextNode("<firstname>added firstname</firstname><lastname>added lastname</lastname><nickname>added nickname</nickname><salary>$10,000</salary></staff>");

您要執行的操作是將此字符串解析為XML，然后將其附加到CombinedStaff-element。

看看這里有關如何從字符串創建XML的公認答案： 如何從Java中的字符串創建XML對象？

並將該解決方案應用於您的xml字符串：

"<staff><firstname>added firstname</firstname><lastname>added lastname</lastname><nickname>added nickname</nickname><salary>$10,000</salary></staff>"

之后，您將得到的文檔添加到原始XML中。 通過執行以下操作：

Node newNode =  doc.importNode(theNewDocument.getDocumentElement() , true); //Need to import prior to appending it

doc.getDocumentElement().appendChild(newNode);  

這是使用DOM附加內容而不是嘗試手動添加的更好的解決方案。

Answer 2

嘗試使用

 TransformerFactory transFactory = TransformerFactory.newInstance();
 Transformer transformer = transFactory.newTransformer();
 transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
 transformer.transform(source, result);