SAX Parser Example

Main.java

import org.xml.sax.SAXException;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.ParserConfigurationException;

import java.io.FileInputStream;
import java.io.InputStream;
import java.io.IOException;

public class Main {
    @SuppressWarnings("CatchAndPrintStackTrace")
    public static void main(String[] args){
        SAXParserFactory spf = SAXParserFactory.newInstance();
        try {
            InputStream xmlInput  = new FileInputStream("student.xml");
            SAXParser saxParser = spf.newSAXParser();
            StudentXMLParser sxp = new StudentXMLParser();
            saxParser.parse(xmlInput, sxp);

            System.out.println("\n*** Read Students ***");
            for (Student s : sxp.getStudents())
                System.out.println(s);
        }
        catch(SAXException|ParserConfigurationException|IOException e){
            e.printStackTrace();
        }
    }
}

import org.xml.sax.SAXException;

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;

import javax.xml.parsers.ParserConfigurationException;

import java.io.FileInputStream;

import java.io.InputStream;

import java.io.IOException;

public class Main {

@SuppressWarnings("CatchAndPrintStackTrace")

public static void main(String[] args){

SAXParserFactory spf = SAXParserFactory.newInstance();

try {

InputStream xmlInput = new FileInputStream("student.xml");

SAXParser saxParser = spf.newSAXParser();

StudentXMLParser sxp = new StudentXMLParser();

saxParser.parse(xmlInput, sxp);

System.out.println("\n*** Read Students ***");

for (Student s : sxp.getStudents())

System.out.println(s);

}

catch(SAXException|ParserConfigurationException|IOException e){

e.printStackTrace();

}

Student.java

public class Student {

    private int id;
    private String name;
    private String address;

    public Student(int id, String name, String address){
        this.id = id;
        this.name = name;
        this.address = address;
    }

    @Override
    public String toString(){
        return name + " (" + id + ") lives at " + address;
    }
}

public class Student {

private int id;

private String name;

private String address;

public Student(int id, String name, String address){

this.id = id;

this.name = name;

this.address = address;

}

@Override

public String toString(){

return name + " (" + id + ") lives at " + address;

}

StudentXMLParser.java

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import java.util.ArrayList;
import java.util.List;

public class StudentXMLParser extends DefaultHandler {

    private List<Student> students;

    private String buffer; 
    
    private int studentId;
    private String studentName;
    private String studentAddress; 

    @Override
    public void startDocument() throws SAXException {
        System.out.println("Start document");
        students = new ArrayList<>();
    }

    @Override
    public void startElement(String namespaceURI,
                             String localName,
                             String qName, 
                             Attributes atts) throws SAXException {
        System.out.println("Start element: " + qName);
        if(qName.equals("student")){
            studentId = Integer.parseInt(atts.getValue("id"));
            System.out.println("id  " + atts.getValue("id"));
        }
           
    }

    @Override
    public void endElement(String namespaceURI,
                           String localName,
                           String qName) throws SAXException {
        System.out.println("End element: " + qName);

        if (qName.equals("address"))
            studentAddress = buffer;
        if (qName.equals("name"))
            studentName = buffer;
        if (qName.equals("student")){
            students.add(new Student(studentId, studentName, studentAddress));
            studentId = -1;
            studentName = "";
            studentAddress = "";
        }

    }

    @Override
    public void endDocument() throws SAXException {
        System.out.println("End document");
    }

    @Override
    public void characters(char ch[], int start, int length)
        throws SAXException {
        buffer = new String(ch, start, length);
        System.out.println("Chars: " + buffer);
    }

    public List<Student> getStudents(){
        return students;
    }
}

import org.xml.sax.Attributes;

import org.xml.sax.SAXException;

import org.xml.sax.helpers.DefaultHandler;

import java.util.ArrayList;

import java.util.List;

public class StudentXMLParser extends DefaultHandler {

private List<Student> students;

private String buffer;

private int studentId;

private String studentName;

private String studentAddress;

@Override

public void startDocument() throws SAXException {

System.out.println("Start document");

students = new ArrayList<>();

}

@Override

public void startElement(String namespaceURI,

String localName,

String qName,

Attributes atts) throws SAXException {

System.out.println("Start element: " + qName);

if(qName.equals("student")){

studentId = Integer.parseInt(atts.getValue("id"));

System.out.println("id " + atts.getValue("id"));

}

@Override

public void endElement(String namespaceURI,

String localName,

String qName) throws SAXException {

System.out.println("End element: " + qName);

if (qName.equals("address"))

studentAddress = buffer;

if (qName.equals("name"))

studentName = buffer;

if (qName.equals("student")){

students.add(new Student(studentId, studentName, studentAddress));

studentId = -1;

studentName = "";

studentAddress = "";

}

@Override

public void endDocument() throws SAXException {

System.out.println("End document");

}

@Override

public void characters(char ch[], int start, int length)

throws SAXException {

buffer = new String(ch, start, length);

System.out.println("Chars: " + buffer);

}

public List<Student> getStudents(){

return students;

}

student.xml

<?xml version="1.0" encoding="UTF-8"?>
<students>
  <student id="800">
    <name>Sherlock Holmes</name>
    <address>221B Baker Street</address>
  </student>
  <student id="801">
    <name>John Watson</name>
    <address>221B Baker Street</address>
  </student>
</students>

<?xml version="1.0" encoding="UTF-8"?>

<name>Sherlock Holmes</name>

<address>221B Baker Street</address>

</student>

<name>John Watson</name>

<address>221B Baker Street</address>

</student>

</students>

Hi There!

Main.java

Student.java

StudentXMLParser.java

student.xml