如何使用JAVA將XML字符串添加到現有的XML文件中？

Question

我有一個名爲temp.xml的XML文件，下面的內容。

<?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XML字符串這樣，

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

我需要這個XML字符串追加到上面的XML文件，這樣最終的XML應該這樣看，

<?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> 

我用這種方式編碼，但我得到一些像;<這樣的垃圾字符被添加到這種xml字符串，

<?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> 

這裏是我的代碼，

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(); 
     } 

    } 
} 

我怎樣才能解決這個問題呢？問題在哪裏？

有人可以幫忙嗎？

Answer 1

試試用

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

Answer 2

不要添加嵌套元素爲文本。

行：

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

你想要做的是削減該字符串作爲XML它，然後將其追加到了combinedstaff元素。

採取在這裏如何從字符串創建XML接受的答案偷看： How to create a XML object from String in Java?

而且適用於你的XML字符串該解決方案：

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

然後你把所得到的文檔並將其添加到您的原始XML。 通過做這樣的事情：

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

doc.getDocumentElement().appendChild(newNode); 

它一個更好的解決方案，使用DOM追加內容，而不是試圖manully做到這一點。