java - Can I use a loop in my XML output method? -

the method below supposed take stored students , generate xml file data. xml structured correctly both entries same. instead of getting data student1 , student2 student2 twice in row. missin here?

public void exportstudentxml(arraylist <student> studentlistin ){     arraylist <student> studentlist = studentlistin;      documentbuilderfactory mydocbuilderfactory = documentbuilderfactory.newinstance();      try{         documentbuilder mydocbuilder = mydocbuilderfactory.newdocumentbuilder();         document documentmodel = mydocbuilder.newdocument();          element root = documentmodel.createelement("studentlist");         documentmodel.appendchild(root);          (student thisstudent : studentlist){             element listelement = documentmodel.createelement("student");             root.appendchild(listelement);              element nameelement = documentmodel.createelement("name");             text nametext = documentmodel.createtextnode(thisstudent.name);             nameelement.appendchild(nametext);             listelement.appendchild(nameelement);              element addresselement = documentmodel.createelement("address");             text addresstext = documentmodel.createtextnode(thisstudent.address);             addresselement.appendchild(addresstext);             listelement.appendchild(addresselement);              element ssnelement = documentmodel.createelement("ssn");             text ssntext = documentmodel.createtextnode(thisstudent.socialsecuritynumber);             ssnelement.appendchild(ssntext);             listelement.appendchild(ssnelement);              element dobelement = documentmodel.createelement("dob");             text dobtext = documentmodel.createtextnode(thisstudent.tostringdob());             dobelement.appendchild(dobtext);             listelement.appendchild(dobelement);              element dogelement = documentmodel.createelement("dog");             text dogtext = documentmodel.createtextnode(thisstudent.tostringdog());             dogelement.appendchild(dogtext);             listelement.appendchild(dogelement);              element gpaelement = documentmodel.createelement("gpa");             text gpatext = documentmodel.createtextnode(thisstudent.tostringgpa());             gpaelement.appendchild(gpatext);             listelement.appendchild(gpaelement);          }         outputformat formattooutput = new outputformat(documentmodel);          formattooutput.setindenting(true);         xmlserializer serializer = new xmlserializer( new fileoutputstream( new file("studentlist.xml")), formattooutput );         serializer.serialize(documentmodel);      }catch(exception e){        }        } 

this code works fine, problem in code didn't show us: class student - declared fields there static means there's 1 copy , when create "multiple students" each new student overrides values of previous one.

remove static keyword before members in class student (name, address , etc) , code work. here's working example few minor modifications of code:

import java.io.file; import javax.xml.parsers.documentbuilder; import javax.xml.parsers.documentbuilderfactory; import javax.xml.transform.transformer; import javax.xml.transform.transformerfactory; import javax.xml.transform.dom.domsource; import javax.xml.transform.stream.streamresult; import org.w3c.dom.document; import org.w3c.dom.element;  class studentstoxml {      public static void main(string[] args) {         arraylist <student> studentlist = new arraylist<>();         studentlist.add(new student("john", "ca", "123"));         studentlist.add(new student("mark", "az", "456"));         exportstudentxml(studentlist);         }      public static void exportstudentxml(arraylist <student> studentlist ){         documentbuilderfactory mydocbuilderfactory = documentbuilderfactory.newinstance();          try{             documentbuilder mydocbuilder = mydocbuilderfactory.newdocumentbuilder();             document documentmodel = mydocbuilder.newdocument();              element root = documentmodel.createelement("studentlist");             documentmodel.appendchild(root);              (student thisstudent : studentlist){                 element listelement = documentmodel.createelement("student");                 root.appendchild(listelement);                  element nameelement = documentmodel.createelement("name");                 nameelement.appendchild(documentmodel.createtextnode(thisstudent.name));                 listelement.appendchild(nameelement);                  element addresselement = documentmodel.createelement("address");                 addresselement.appendchild(documentmodel.createtextnode(thisstudent.address));                 listelement.appendchild(addresselement);                  element ssnelement = documentmodel.createelement("ssn");                 ssnelement.appendchild(documentmodel.createtextnode(thisstudent.socialsecuritynumber));                 listelement.appendchild(ssnelement);              }             // write content xml file             transformerfactory transformerfactory = transformerfactory.newinstance();             transformer transformer = transformerfactory.newtransformer();             domsource source = new domsource(documentmodel);             streamresult result = new streamresult(new file("studentlist.xml"));              transformer.transform(source, result);                 system.out.println("file saved!");          }catch(exception e){             e.printstacktrace()         }     } }   class student {      student (string name, string addr, string soc) {         this.name = name;         address = addr;         socialsecuritynumber = soc;     }     static string name = "";     static string address = "";     static string socialsecuritynumber = "";  } 

output file:

<?xml version="1.0" encoding="utf-8" standalone="no"?> <studentlist>     <student><name>john</name><address>ca</address><ssn>123</ssn></student>     <student><name>mark</name><address>az</address><ssn>456</ssn></student> </studentlist>