Java Language XOM - XML Object Model Writing to a XML File
Example
Writing to a XML File using XOM is very similar to reading it except in this case we are making the instances instead of retrieving them off the root.
To make a new Element use the constructor Element(String name). You will want to make a root element so that you can easily add it to a Document.
Element root = new Element("root");
The Element class has some handy methods for editing elements. They are listed below:
appendChild(String name)- this will basically set the value of the element to name.appendChild(Node node)- this will makenodethe elements parent. (Elements are nodes so you can parse elements).addAttribute(Attribute attribute)- will add an attribute to the element.
The Attribute class has a couple of different constructors. The simplest one is Attribute(String name, String value).
Once you have all of your elements add to your root element you can turn it into a Document. Document will take a Element as an argument in it's constructor.
You can use a Serializer to write your XML to a file. You will need to make a new output stream to parse in the constructor of Serializer.
FileOutputStream fileOutputStream = new FileOutputStream(file);
Serializer serializer = new Serializer(fileOutputStream, "UTF-8");
serializer.setIndent(4);
serializer.write(doc);
Example
Code:
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import nu.xom.Attribute;
import nu.xom.Builder;
import nu.xom.Document;
import nu.xom.Element;
import nu.xom.Elements;
import nu.xom.ParsingException;
import nu.xom.Serializer;
public class XMLWriter{
public static void main(String[] args) throws UnsupportedEncodingException,
IOException{
// root element <example>
Element root = new Element("example");
// make a array of people to store
Person[] people = {new Person("Smith", "Dan", "years", "green", 23),
new Person("Autry", "Bob", "months", "N/A", 3)};
// add all the people
for (Person person : people){
// make the main person element <person>
Element personElement = new Element("person");
// make the name element and it's children: first and last
Element nameElement = new Element("name");
Element firstNameElement = new Element("first");
Element lastNameElement = new Element("last");
// make age element
Element ageElement = new Element("age");
// make favorite color element
Element favColorElement = new Element("fav_color");
// add value to names
firstNameElement.appendChild(person.getFirstName());
lastNameElement.appendChild(person.getLastName());
// add names to name
nameElement.appendChild(firstNameElement);
nameElement.appendChild(lastNameElement);
// add value to age
ageElement.appendChild(String.valueOf(person.getAge()));
// add unit attribute to age
ageElement.addAttribute(new Attribute("unit", person.getAgeUnit()));
// add value to favColor
favColorElement.appendChild(person.getFavoriteColor());
// add all contents to person
personElement.appendChild(nameElement);
personElement.appendChild(ageElement);
personElement.appendChild(favColorElement);
// add person to root
root.appendChild(personElement);
}
// create doc off of root
Document doc = new Document(root);
// the file it will be stored in
File file = new File("out.xml");
if (!file.exists()){
file.createNewFile();
}
// get a file output stream ready
FileOutputStream fileOutputStream = new FileOutputStream(file);
// use the serializer class to write it all
Serializer serializer = new Serializer(fileOutputStream, "UTF-8");
serializer.setIndent(4);
serializer.write(doc);
}
private static class Person {
private String lName, fName, ageUnit, favColor;
private int age;
public Person(String lName, String fName, String ageUnit, String favColor, int age){
this.lName = lName;
this.fName = fName;
this.age = age;
this.ageUnit = ageUnit;
this.favColor = favColor;
}
public String getLastName() { return lName; }
public String getFirstName() { return fName; }
public String getAgeUnit() { return ageUnit; }
public String getFavoriteColor() { return favColor; }
public int getAge() { return age; }
}
}
This will be the contents of "out.xml":
