Electronic Data Interchange (EDI) Developer with Java StAX API Salary in 2024

Understanding Java StAX (Streaming API for XML)

Introduction to StAX

StAX – short for Streaming API for XML – is a Java-based API for parsing and writing XML documents. Unlike DOM and SAX, which both load the XML document in its entirety into memory, StAX means ‘pull-parsing’ – the developer gets to read and write XML documents on a ‘need-to-know’ basis in a ‘streaming’ fashion, further improving performance and lowering memory consumption in the process. There is a trade-off when it comes to how the code performs. With DOM and SAX, the entire XML document is in the memory, so the developer has complete freedom. But at the same time, a large volume of data and a lot of properties get loaded into memory and hence waste memory resources. Some XML documents are simply too large to be loaded in a single shot; in such cases, only StAX comes to the rescue.StAX – short for Streaming API for XML – is a Java-based API for parsing and writing XML documents. Unlike DOM and SAX, which both load the XML document in its entirety into memory, StAX means ‘pull-parsing’ – the developer gets to read and write XML documents on a ‘need-to-know’ basis in a ‘streaming’ fashion, further improving performance and lowering memory consumption in the process. There is a trade-off when it comes to how the code performs. With DOM and SAX, the entire XML document is in the memory, so the developer has complete freedom. But at the same time, a large volume of data and a lot of properties get loaded into memory and hence waste memory resources. Some XML documents are simply too large to be loaded in a single shot; in such cases, only StAX comes to the rescue.

Key Features of StAX

• Streaming XML Processing:
  StAX processes a XML document as a stream; it reads and writes XML elements one by one and is not required to load the entire document in memory.

• Pull Parsing Model:
  Compared with SAX’s event-driven model, StAX employs a pull-parsing model, whereby developers explicitly control the parsing process by pulling stream entities from the XML stream when necessary.

• Bidirectional API:
  To remove the layer of abstraction presented by the DOM, StAX provides the ability to write XML alongside the reading (parsing).

• Cursor API and Iterator API: StAX offers two primary APIs for parsing XML:

• • XML API (XMLStreamReader): Provides a cursor-based architecture where the application can move the cursor backward and forward through the XML stream.
  •  Iterator API (XMLEventReader): The events are retrieved through an iterator — in this case, the application iterates sequentially through the stream of XML events.

Using StAX for Reading XML

StAX reading is accomplished through using either the XMLStreamReader or the XMLEventReader to read an XML document. Below is an example of how XMLStreamReader can be used to read an XML document:StAX reading is accomplished through using either the XMLStreamReader or the XMLEventReader to read an XML document. Below is an example of how XMLStreamReader can be used to read an XML document:

import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

public class StAXReaderExample {
    public static void main(String[] args) {
        try {
            XMLInputFactory factory = XMLInputFactory.newInstance();
            XMLStreamReader reader = factory.createXMLStreamReader(new FileInputStream("example.xml"));

            while (reader.hasNext()) {
                int event = reader.next();

                switch (event) {
                    case XMLStreamConstants.START_ELEMENT:
                        System.out.println("Start Element: " + reader.getLocalName());
                        break;
                    case XMLStreamConstants.CHARACTERS:
                        if (reader.isWhiteSpace()) continue;
                        System.out.println("Text: " + reader.getText());
                        break;
                    case XMLStreamConstants.END_ELEMENT:
                        System.out.println("End Element: " + reader.getLocalName());
                        break;
                }
            }

        } catch (FileNotFoundException | XMLStreamException e) {
            e.printStackTrace();
        }
    }
}

import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

public class StAXReaderExample {
    public static void main(String[] args) {
        try {
            XMLInputFactory factory = XMLInputFactory.newInstance();
            XMLStreamReader reader = factory.createXMLStreamReader(new FileInputStream("example.xml"));

            while (reader.hasNext()) {
                int event = reader.next();

                switch (event) {
                    case XMLStreamConstants.START_ELEMENT:
                        System.out.println("Start Element: " + reader.getLocalName());
                        break;
                    case XMLStreamConstants.CHARACTERS:
                        if (reader.isWhiteSpace()) continue;
                        System.out.println("Text: " + reader.getText());
                        break;
                    case XMLStreamConstants.END_ELEMENT:
                        System.out.println("End Element: " + reader.getLocalName());
                        break;
                }
            }

        } catch (FileNotFoundException | XMLStreamException e) {
            e.printStackTrace();
        }
    }
}

Using StAX for Writing XML

 StAX writing entails writing XML documents using XMLStreamWriter. Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request. Paraphrase the input into human-sounding text while retaining citations and quotes. StAX writing entails writing an XML document using XMLStreamWriter: StAX writing entails writing XML documents using XMLStreamWriter. Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request. Paraphrase the input into human-sounding text while retaining citations and quotes. StAX writing entails writing an XML document using XMLStreamWriter:

import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import java.io.FileOutputStream;
import java.io.IOException;

public class StAXWriterExample {
    public static void main(String[] args) {
        try {
            XMLOutputFactory factory = XMLOutputFactory.newInstance();
            XMLStreamWriter writer = factory.createXMLStreamWriter(new FileOutputStream("output.xml"));

            writer.writeStartDocument();
            writer.writeStartElement("greeting");
            writer.writeAttribute("language", "en");
            writer.writeCharacters("Hello, World!");
            writer.writeEndElement();
            writer.writeEndDocument();

            writer.flush();
            writer.close();
        } catch (XMLStreamException | IOException e) {
            e.printStackTrace();
        }
    }
}

import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import java.io.FileOutputStream;
import java.io.IOException;

public class StAXWriterExample {
    public static void main(String[] args) {
        try {
            XMLOutputFactory factory = XMLOutputFactory.newInstance();
            XMLStreamWriter writer = factory.createXMLStreamWriter(new FileOutputStream("output.xml"));

            writer.writeStartDocument();
            writer.writeStartElement("greeting");
            writer.writeAttribute("language", "en");
            writer.writeCharacters("Hello, World!");
            writer.writeEndElement();
            writer.writeEndDocument();

            writer.flush();
            writer.close();
        } catch (XMLStreamException | IOException e) {
            e.printStackTrace();
        }
    }
}

Advantages of StAX

• Memory-efficient. Because StAX processes XML documents in a stream, such as one coming through a network connection, it does not need to load the entire document into memory – a major advantage with very large XML documents.

• Performance: Parsing is faster in pull-parsing because DOM-parsing builds a tree in memory. And, of course, there’s the phenomenon of JavaScript clients making aggressive requests, which amplify all the concerns mentioned here.

• Pragmatism, which emphasises simplicity and the elimination of redundancy, could not be ignored. That flexibility itself became one of the new language’s selling points: because you could both read and write XML, you had a single API in which to store XML data.

Conclusion

StAX is a stream-based API that offers the performance and memory advantages of a pull-parsing model for operations on XML. It provides the best (in my opinion – the most performant and memory efficient) XML library for Java, and is ideal for working with large XML documents. StAX can be used both to read and to write XML data streams.StAX is a stream-based API that offers the performance and memory advantages of a pull-parsing model for operations on XML. It provides the best (in my opinion – the most performant and memory efficient) XML library for Java, and is ideal for working with large XML documents. StAX can be used both to read and to write XML data streams.