Interpret the original JSR 173 stream API for XML reference framework technology in the Java class library
JSR 173 Stream API FOR XML Reference Technology Original Technology -Interpretation and Example
introduction:
The JSR 173 stream API For XML reference implementation framework in the JAVA class library is a technology used to process XML data.This article will interpret the technical principles of the framework and provide some Java code examples to help readers better understand.
1. What is JSR 173 stream API for XML reference framework?
JSR 173 defines a set of Java API for processing XML data.The JSR 173 framework is divided into two main parts: xmlReader and xmleventwriter.The XMLREADER class is used to read the data of XML documents, while the Xmleventwriter class is used to write XML data.
2. Examples of the XMLREADER class
The XmlReader class provides many methods to analyze and read the contents of XML documents.Below is a simple example, showing how to use the XMLREADER class to read the elements and attributes in the XML document.
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
public class XMLReaderExample {
public static void main(String[] args) {
try {
// Create a XMLINPUTFACTORY object
XMLInputFactory inputFactory = XMLInputFactory.newInstance();
// Create a XMLSTREAMREADER object
XMLStreamReader reader = inputFactory.createXMLStreamReader(new FileInputStream("example.xml"));
// Read the contents of the XML document
while (reader.hasNext()) {
int event = reader.next();
// Treatment of different types of events
switch (event) {
case XMLStreamReader.START_ELEMENT:
System.out.println("Start Element: " + reader.getLocalName());
// Get the attribute
for (int i = 0; i < reader.getAttributeCount(); i++) {
System.out.println("Attribute: " + reader.getAttributeLocalName(i) +
" = " + reader.getAttributeValue(i));
}
break;
case XMLStreamReader.END_ELEMENT:
System.out.println("End Element: " + reader.getLocalName());
break;
case XMLStreamReader.CHARACTERS:
// Treat the text node
if (reader.getText().trim().length() > 0) {
System.out.println("Text: " + reader.getText());
}
break;
}
}
// Close XMLSTREAMREADER object
reader.close();
} catch (XMLStreamException | FileNotFoundException e) {
e.printStackTrace();
}
}
}
In the above example, we use the XML document named "Example.xml" with XMLSTREAMREADER objects.By using the XMLREADER class method, such as next () and getlocalName (), we can obtain different elements and attributes in XML documents and processed as needed.
3. Example of the use of XMLEVENTWRITER class
The Xmleventwriter class is used to write XML data into the output stream or file.Below is a simple example, showing how to use the XmleventWriter class to generate a simple XML document.
import javax.xml.stream.XMLEventFactory;
import javax.xml.stream.XMLEventWriter;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.*;
import java.io.FileOutputStream;
import java.io.OutputStream;
public class XMLEventWriterExample {
public static void main(String[] args) {
try {
// Create a XMLOUTPUTFACTORY object
XMLOutputFactory outputFactory = XMLOutputFactory.newInstance();
// Create a XMLEVENTWRITER object
OutputStream outputStream = new FileOutputStream("output.xml");
XMLEventWriter writer = outputFactory.createXMLEventWriter(outputStream);
// Create a XMLEVENTFACTORY object
XMLEventFactory eventFactory = XMLEventFactory.newInstance();
// Create the start label of the XML document
StartDocument startDocument = eventFactory.createStartDocument();
writer.add(startDocument);
writer.add(eventFactory.createStartElement("", "", "root"));
// Create a attribute
Attribute attribute = eventFactory.createAttribute("attribute", "value");
// Create an element
StartElement element = eventFactory.createStartElement("", "", "element", attribute.iterator(), null);
writer.add(element);
// Create a text node
Characters text = eventFactory.createCharacters("This is a text node");
writer.add(text);
// Create the end of the element
EndElement endElement = eventFactory.createEndElement("", "", "element");
writer.add(endElement);
// Create the end of the XML document
writer.add(eventFactory.createEndElement("", "", "root"));
writer.add(eventFactory.createEndDocument());
// Close Xmleventwriter object
writer.close();
} catch (XMLStreamException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
In the above example, we use the XMLEVENTWRITER object to write XML data into a file named "Output.xml".By using the method of XMLEVENTFACTORY class, such as CreateStartelement () and CreateCharas (), we can generate various parts of the XML document, and use the ADD () method of xmleventwriter to add them to XML.Finally, we close the Xmleventwriter object to complete the generation of XML documents.
in conclusion:
This article interprets the reference framework of the JSR 173 stream API for XML in the JAVA library.Through the use of examples of XMLreader and XMLEVENTWRITER class, readers can better understand and use this framework to process XML data.It is hoped that this article can provide readers with detailed information about the technical principles and instances of the JSR 173 framework.