adding content to existing xml with jdom
Solution 1
Basically, you need to load an existing xml file and make a Document
of it by parsing it and getting the root element from it. If the file does not exist then create a new document and a new root element. After that you can go on with the code you have shown.
Create a class Product
to hold product data. Passing product data each as argument to a method is a no-go.
Product class (for simplicity all fields are public, this not a good practice, you should make them at least protected and for each a getter and a setter method)
public class Product {
public String categorie;
public String code;
public String naamartikel;
public String beschrijvingartikel;
public double prijz;
public String imgurl;
public String imgurl2;
public String imgurl3;
public String imgurl4;
public String imgurl5;
}
Writer method
public static void Writer(Product product) throws JDOMException, IOException {
Document document = null;
Element root = null;
File xmlFile = new File("products.xml");
if(xmlFile.exists()) {
// try to load document from xml file if it exist
// create a file input stream
FileInputStream fis = new FileInputStream(xmlFile);
// create a sax builder to parse the document
SAXBuilder sb = new SAXBuilder();
// parse the xml content provided by the file input stream and create a Document object
document = sb.build(fis);
// get the root element of the document
root = document.getRootElement();
fis.close();
} else {
// if it does not exist create a new document and new root
document = new Document();
root = new Element("productlist");
}
String prijs = String.valueOf(product.prijz);
String naamelement = "naam";
String categorieelement = "category";
String descriptionelement = "description";
Element child = new Element("product");
child.addContent(new Element(categorieelement).setText(product.categorie));
child.addContent(new Element("code").setText(product.code));
child.addContent(new Element(naamelement).setText(product.naamartikel));
child.addContent(new Element(descriptionelement).setText(product.beschrijvingartikel));
child.addContent(new Element("price").setText(prijs));
child.addContent(new Element("image").setText(product.imgurl));
child.addContent(new Element("image").setText(product.imgurl2));
child.addContent(new Element("image").setText(product.imgurl3));
child.addContent(new Element("image").setText(product.imgurl4));
child.addContent(new Element("image").setText(product.imgurl5));
root.addContent(child);
document.setContent(root);
try {
FileWriter writer = new FileWriter("products.xml");
XMLOutputter outputter = new XMLOutputter();
outputter.setFormat(Format.getPrettyFormat());
outputter.output(document, writer);
outputter.output(document, System.out);
writer.close(); // close writer
} catch (IOException e) {
e.printStackTrace();
}
}
and finally a little test
public static void main(String[] args) throws JDOMException, IOException {
Product product = null;
product = new Product();
product.categorie = "cat1";
product.code = "code1";
product.naamartikel = "naam1";
product.beschrijvingartikel = "beschrijving1";
product.prijz = 100d;
product.imgurl = "http://localhost/img1.png";
product.imgurl2 = "http://localhost/img2.png";
product.imgurl3 = "http://localhost/img3.png";
product.imgurl4 = "http://localhost/img5.png";
product.imgurl5 = "http://localhost/img5.png";
Writer(product);
product = new Product();
product.categorie = "cat2";
product.code = "code2";
product.naamartikel = "naam2";
product.beschrijvingartikel = "beschrijving2";
product.prijz = 200d;
product.imgurl = "http://localhost/img21.png";
product.imgurl2 = "http://localhost/img22.png";
product.imgurl3 = "http://localhost/img23.png";
product.imgurl4 = "http://localhost/img25.png";
product.imgurl5 = "http://localhost/img25.png";
Writer(product);
product = new Product();
product.categorie = "cat3";
product.code = "code3";
product.naamartikel = "naam3";
product.beschrijvingartikel = "beschrijving3";
product.prijz = 300d;
product.imgurl = "http://localhost/img31.png";
product.imgurl2 = "http://localhost/img32.png";
product.imgurl3 = "http://localhost/img33.png";
product.imgurl4 = "http://localhost/img35.png";
product.imgurl5 = "http://localhost/img35.png";
Writer(product);
}
Also, file name products.xml
should not be hard coded in java file; instead pass it as an argument when you run the program.
Solution 2
Replace root=document.getRootElement();
by
root = document.detachRootElement();
because an Element can be associated to only one document in jdom.
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Boyen
Updated on June 04, 2022Comments
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Boyen over 1 year
package xml.dierenshop.flaming.v1; import org.jdom2.Document; import org.jdom2.Element; import org.jdom2.output.XMLOutputter; import org.jdom2.output.Format; import java.io.FileWriter; import java.io.IOException; public class Writer { public void Writer(String categorie, String code, String naamartikel, String beschrijvingartikel, double prijz, String imgurl, String imgurl2, String imgurl3, String imgurl4, String imgurl5) { String prijs = String.valueOf(prijz); Document document = new Document(); Element root = new Element("productlist"); String naamelement = "naam"; String categorieelement = "category"; String descriptionelement = "description"; Element child = new Element("product"); child.addContent(new Element(categorieelement).setText(categorie)); child.addContent(new Element("code").setText(code)); child.addContent(new Element(naamelement).setText(naamartikel)); child.addContent(new Element(descriptionelement).setText(beschrijvingartikel)); child.addContent(new Element("price").setText(prijs)); child.addContent(new Element("image").setText(imgurl)); child.addContent(new Element("image").setText(imgurl2)); child.addContent(new Element("image").setText(imgurl3)); child.addContent(new Element("image").setText(imgurl4)); child.addContent(new Element("image").setText(imgurl5)); root.addContent(child); document.setContent(root); try { FileWriter writer = new FileWriter("products.xml"); XMLOutputter outputter = new XMLOutputter(); outputter.setFormat(Format.getPrettyFormat()); outputter.output(document, writer); outputter.output(document, System.out); } catch (IOException e) { e.printStackTrace(); } } }
This is my class for writing an xml file with variables from my main class. The output here would be :
Now I have a problem, the next time I run this java application I want it to add a new product but keep the old one. However every time I try this, it replaces the old data with the new data.
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Boyen over 10 yearsI managed to figure out something simular myself at school, thanks alot though !