Pass Parameter in SAX Parsing

XML File

Create new package named data. In this package, create new xml file named products.xml as below:

<?xml version="1.0" encoding="UTF-8"?>
<products>
	<product>
		<id>p01</id>
		<name>name 1</name>
		<price currency="usd">20</price>
		<quantity>5</quantity>
		<weight unit="kg">2.1</weight>
		<date format="dd/MM/yyyy">02/03/2017</date>
		<status>true</status>
	</product>
	<product>
		<id>p02</id>
		<name>name 2</name>
		<price currency="eur">12</price>
		<quantity>3</quantity>
		<weight unit="kg">6.5</weight>
		<date format="dd/MM/yyyy">24/11/2018</date>
		<status>true</status>
	</product>
	<product>
		<id>p03</id>
		<name>name 3</name>
		<price currency="aud">13</price>
		<quantity>1</quantity>
		<weight unit="kg">7.8</weight>
		<date format="dd/MM/yyyy">14/10/2018</date>
		<status>false</status>
	</product>
</products>

Create ProductModel Class

In models package, create new java class named ProductModel.java contains methods to interact with the xml file.

package models;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class ProductModel {

	private boolean result = false;

	public boolean checkId(String id) {
		try {
			SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
			SAXParser saxParser = saxParserFactory.newSAXParser();
			saxParser.parse("src\\data\\products.xml", new ProductDefaultHandler(id));
		} catch (Exception e) {
			this.result = false;
		}
		return this.result;
	}

	private class ProductDefaultHandler extends DefaultHandler {

		private String tagName = "";
		private String id;

		public ProductDefaultHandler(String id) {
			this.id = id;
		}

		@Override
		public void startDocument() throws SAXException {
			result = false;
		}

		@Override
		public void startElement(String uri, String localName, String qName, Attributes attributes)
				throws SAXException {
			this.tagName = qName;
		}

		@Override
		public void characters(char[] ch, int start, int length) throws SAXException {
			String content = new String(ch, start, length);
			if (this.tagName.equalsIgnoreCase("id")) {
				if (content.equalsIgnoreCase(this.id)) {
					result = true;
				}
				this.tagName = "";
			}
		}

	}

}

Structure of Project

Run Application

package demo;

import models.ProductModel;

public class Main {

	public static void main(String[] args) {

		ProductModel productModel = new ProductModel();
		System.out.println("Result 1: " + productModel.checkId("p01"));
		System.out.println("Result 2: " + productModel.checkId("p04"));

	}

}

Output

Result 1: true
Result 2: false