Java XML - Overview

What is XML?

XML is a simple text-based language which was designed to store and transport data in plain text format. It stands for Extensible Markup Language. Following are some of the salient features of XML.

• XML is a markup language.
• XML is a tag based language like HTML.
• XML tags are not predefined like HTML.
• You can define your own tags which is why it is called extensible language.
• XML tags are designed to be self-descriptive.
• XML is W3C Recommendation for data storage and data transfer.

Example

<?xml version = "1.0"?>
<Class>
   <Name>First</Name>
   <Sections>
      <Section>
         <Name>A</Name>
         <Students>
            <Student>Rohan</Student>
            <Student>Mohan</Student>
            <Student>Sohan</Student>
            <Student>Lalit</Student>
            <Student>Vinay</Student>
         </Students>
      </Section>
      
      <Section>
         <Name>B</Name>
         <Students>
            <Student>Robert</Student>
            <Student>Julie</Student>
            <Student>Kalie</Student>
            <Student>Michael</Student>
         </Students>
      </Section>
   </Sections>
</Class>

Advantages

Following are the advantages that XML provides −

• Technology agnostic − Being plain text, XML is technology independent. It can be used by any technology for data storage and data transfer purpose.
• Human readable − XML uses simple text format. It is human readable and understandable.
• Extensible − In XML, custom tags can be created and used very easily.
• Allow Validation − Using XSD, DTD and XML structures can be validated easily.

Disadvantages

Following are the disadvantages of using XML −

• Redundant Syntax − Normally XML files contain a lot of repetitive terms.
• Verbose − Being a verbose language, XML file size increases the transmission and storage costs.