Merging of xml files java

Question

I have two different xml files described as below and want to merge these xml files and get the expected output may be using xpath or dom parsing but not XSLT since the xmls are always not the same

XML1.xml

<personinfo>
   <person>
     <name><name>
     <age></age>
     <address>
     <street></street>
     <city></city>
     <address>
   </person>
   <person>
     <name><name>
     <age></age>
     <address>
     <street></street>
     <city></city>
     <address>
   </person>
   <person>
     <name><name>
     <age></age>
     <address>
     <street></street>
     <city></city>
     <address>
   </person>
</personinfo>

XML2.xml

<personinfo>
   <person>
     <name>tom<name>
     <age>26</age>
     <address>
     <street>main street</street>
     <city>washington</city>
     <address>
   </person>
   <person>
     <name>mike<name>
     <age>30</age>
     <address>
     <street>first street</street>
     <city>dallas</city>
     <address>
   </person>
</personinfo>

Expected.xml

<personinfo>
   <person>
     <name>tom<name>
     <age>26</age>
     <address>
     <street>main street</street>
     <city>washington</city>
     <address>
   </person>
   <person>
     <name>mike<name>
     <age>30</age>
     <address>
     <street>first street</street>
     <city>dallas</city>
     <address>
   </person>
   <person>
     <name><name>
     <age></age>
     <address>
     <street></street>
     <city></city>
     <address>
   </person>
</personinfo>

Thanks in advance....

Answer 1

If you have the flexibility to create a new xml file, you can parse each of them using any parser you are comfortable with. Store the tags in a LinkedList of String LinkedLists and the tag values in a HashMap of the following type: LinkedHashMap data= new LinkedHashMap();

You can then call the tag names from the linked lists, append the tag values from the Hash Map and write them out to a new XML file. When I did merging of XMLs, this was the procedure I used. Hope this helps

Answer 2

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(file);
doc.getDocumentElement().normalize();
NodeList nodeLst = doc.getElementsByTagName("employee");
for (int s = 0; s < nodeLst.getLength(); s++) 
{
stkey=getXMLData(s,nodeLst,"id");
     keylist.add(stkey);// adding integer keys to a Linked List
data.put(stkey, stkey);                 
data.put(stkey+"first",getXMLData(s,nodeLst,"firstname"));                  
data.put(stkey+"last",getXMLData(s,nodeLst,"lastname"));                    
     data.put(stkey+"loc",getXMLData(s,nodeLst,"location"));    
     data.put(stkey+"occ",getXMLData(s,nodeLst,"occupation"));

}

this will get the tag values in the hash map and the tag names in the linked list. to make your work easier, you can append the type of tag to the hashmap key. For example: if my key is the Employee ID(in my case), I append "first" to it. Lets say some one has an id: 10001. his data would be stored as: 10001, then 10001first, 10001last, 10001loc,10001occ. Now, you can call each hashmap key, get the element as per appended tag name and concatenate to your xml file. Hope this helps.