如何使用xstream在xml文件中包含/處理元數據/註釋？

Question

我使用XStream（http://x-stream.github.io/）將Java對象寫入XML並將這些XML文件作爲Java對象讀回，如此;

// Writing a Java object to xml 
File xmlFile = new File("/", "myObject.xml"); 
FileOutputStream out = new FileOutputStream(xmlFile); 
MyObject myObject = new MyObject(); 
xstream.toXML(myObject, out); 

// Reading the Java object in again 
FileInputStream xmlFile = ... 
XStream xStream = new XStream(); 
MyObject myObject = xStream.fromXML(xmlFile); 

基本上，我想包括在XML文件中額外的信息，當我寫它 - 例如， 'Version1'，無論是作爲xml評論還是嵌入信息的其他方式 - 這都有可能嗎？

因此，當我再次讀取xml文件時，我希望能夠檢索到這些額外的信息。

請注意，我知道我可以添加一個額外的字符串字段或任何對MyObject - 但我不能這樣做在這種情況下（即修改MyObject）。

非常感謝！

Answer 1

正如Makky指出的那樣，XStream忽略了任何評論，所以我通過以下操作得到了這個結果：

// Writing a comment at the top of the xml file, then writing the Java object to the xml file 
File xmlFile = new File("/", "myObject.xml"); 
FileOutputStream out = new FileOutputStream(xmlFile); 

String xmlComment = "<!-- Comment -->" 
out.write(xmlComment.getBytes()); 
out.write("\n".getBytes()); 

MyObject myObject = new MyObject(); 
xstream.toXML(myObject, out); 

// Reading the comment from the xml file, then deserilizing the object; 
final FileBasedLineReader xmlFileBasedLineReader = new FileBasedLineReader(xmlFile); 
final String commentInXmlFile = xmlFileBasedLineReader.nextLine(); 

FileInputStream xmlFile = ... 
XStream xStream = new XStream(); 
MyObject myObject = xStream.fromXML(xmlFile);