标签：java xml document class jdom
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();
}
}
}
这是我用我的主类编写带有变量的xml文件的类.
这里的输出是：
现在我有一个问题,下次我运行这个java应用程序时,我希望它添加一个新产品,但保留旧产品.但是每次我尝试这个时,它都会用新数据替换旧数据.
解决方法:
基本上,您需要加载一个现有的xml文件,并通过解析它并从中获取根元素来创建它的Document.如果该文件不存在,则创建一个新文档和一个新的根元素.之后,您可以继续使用您显示的代码.
创建一个产品类来保存产品数据.将每个产品数据作为参数传递给方法是不行的.
产品类(为简单起见,所有字段都是公开的,这不是一个好的做法,你应该至少保护它们,并为每个字段设置getter和setter方法)
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;
}
作家方法
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();
}
}
最后一点点测试
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);
}
另外,文件名products.xml不应该在java文件中进行硬编码;而是在运行程序时将其作为参数传递.
标签：java,xml,document,class,jdom 来源： https://codeday.me/bug/20190529/1179345.html
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