SpringSource Javax XML Stream Technical Principles Detailed Explanation
SpringSource's Javax XML STREAM technology is a Java API for processing XML, which provides a flow -based processing method based on event.It allows developers to read and write XML data on demand without loading the entire XML document into memory.In this article, we will introduce the principles of SpringSource Javax XML STREAM technology in detail, and provide some simple Java code examples.
XML (scalable mark language) is a widely used data exchange format that is used to transmit and store data between different platforms and applications.In order to process XML data, developers can use different APIs such as DOM (Document Object Model) or SAX (Simple API For XML).However, DOM loads the entire XML document to the memory, and SAX is an event -based parster. Developers need to write a large number of events processing code.In contrast, SpringSource Javax XML Stream technology provides a simpler and efficient XML processing method.
SpringSource Javax XML Stream technology is based on XMLSTREAMREADER and XMLSTREAMWRITER.XMLSTREAMREADER allows developers to read the XML event one by one, while XMLSTREAMWRITER allows developers to write the XML event one by one.Through these two interfaces, the streaming of XML can be achieved, so as to avoid loading the entire XML document into the memory.
Below is a simple example of using SpringSource Javax XML Stream technology to analyze and write XML.Suppose we have an XML file called "Books.xml", which contains some books information.
First, we need to create an XMLSTREAMREADER object to analyze XML files.The code is shown below:
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 XMLStreamReaderExample {
public static void main(String[] args) {
try {
XMLInputFactory factory = XMLInputFactory.newInstance();
XMLStreamReader reader = factory.createXMLStreamReader(new FileInputStream("books.xml"));
while (reader.hasNext()) {
int event = reader.next();
if (event == XMLStreamConstants.START_ELEMENT) {
if (reader.getLocalName().equals("book")) {
String title = reader.getAttributeValue(null, "title");
System.out.println("Book Title: " + title);
}
}
}
reader.close();
} catch (XMLStreamException | FileNotFoundException e) {
e.printStackTrace();
}
}
}
The above code first creates a XMLINPUTFACTORY object and uses it to create a XMLSTREAMREADER object to analyze the "Books.xml" file.Next, the code reads the XML event by circulating, and obtained its "Title" attribute value when encountering the "Book" element and printed it.
Similarly, we can also use xmlstreamWriter to create a XML file and write data.The following is an example code:
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 XMLStreamWriterExample {
public static void main(String[] args) {
try {
XMLOutputFactory factory = XMLOutputFactory.newInstance();
XMLStreamWriter writer = factory.createXMLStreamWriter(new FileOutputStream("output.xml"));
writer.writeStartDocument("1.0");
writer.writeStartElement("books");
writer.writeStartElement("book");
writer.writeAttribute("title", "Java Programming");
writer.writeEndElement();
writer.writeStartElement("book");
writer.writeAttribute("title", "Spring in Action");
writer.writeEndElement();
writer.writeEndElement();
writer.writeEndDocument();
writer.close();
} catch (XMLStreamException | IOException e) {
e.printStackTrace();
}
}
}
The above code creates a XMLOUTPUTFACTORY object and uses it to create a XMLstreamWriter object to write the XML event by one by one.The code uses WritestartDocument () method to write a statement of the XML document, then write the root element "Books", then write two "Book" elements, and set the "title" attribute value for each element.Finally, the code uses the WRITEENDELEMENT () method to end the writing, and call the WritendDocument () method to end the xml document writing.The generated xml file is called "Output.xml".
To sum up, SpringSource Javax XML Stream technology provides a simple and efficient method for processing XML data.Through XMLSTREAMREADER and XMLSTREAMWRITER interfaces, developers can analyze and write XML data as needed, without loading the entire XML document to the memory.This article provides some example code that uses SpringSource Javax XML Stream technology to help developers better understand their principles and usage.
