How to validate an xml document against a schema

STEP 1: Create the XML

To create a new XML file, start eclipse IDE and choose File->New->Other->XML file->Create XML file from XML template.
Model the data of interest in the XML file. In my case, I have created the following XML.

The teams.xml file

<?xml version="1.0" encoding="UTF-8"?>
<team>
 <name>the great team</name>
 <description>these team was recruited by google to develop a secret product</description>
 <developers>
  <developer role="frontend">
   <name>John Carrot</name>
  </developer>
  <developer role="backend">
   <name>Joshua Allock</name>
  </developer>
  <developer role="frontend">
   <name>Brendan Tich</name>
  </developer>
 </developers>
</team>

XML Schema Primer

Table of Contents

1 Introduction
2 Basic Concepts: The Purchase Order
    2.1 The Purchase Order Schema
    2.2 Complex Type Definitions, Element & Attribute Declarations
    2.3 Simple Types
    2.4 Anonymous Type Definitions
3 Advanced Concepts I: Namespaces, Schemas & Qualification
    3.1 Target Namespaces & Unqualified Locals
    3.2 Qualified Locals
    3.3 Global vs. Local Declarations
    3.4 Undeclared Target Namespaces

1 Introduction

Basic Concepts: The Purchase Order (§2) covers the basic mechanisms of XML Schema. It describes how to declare the elements and attributes that appear in XML documents, the distinctions between simple and complex types, defining complex types, the use of simple types for element and attribute values, schema annotation, a simple mechanism for re-using element and attribute definitions, and nil values.

Advanced Concepts I: Namespaces, Schemas & Qualification (§3), explains the basics of how namespaces are used in XML and schema documents.

2 Basic Concepts: The Purchase Order

The purpose of XML schemas

• a schema defines a class of XML documents (is a description of an XML document)
• an instance document is an XML document that conforms to a particular schema

The instance document, the po.xml file, describes a purchase order that may be generated by a product ordering application.

Example

The Purchase Order, po.xml

<?xml version="1.0"?>
<purchaseOrder orderDate="1999-10-20">
   <shipTo country="US">
      <name>Alice Smith</name>
      <street>123 Maple Street</street>
      <city>Mill Valley</city>
      <state>CA</state>
      <zip>90952</zip>
   </shipTo>
   <billTo country="US">
      <name>Robert Smith</name>
      <street>8 Oak Avenue</street>
      <city>Old Town</city>
      <state>PA</state>
      <zip>95819</zip>
   </billTo>
   <comment>Hurry, my lawn is going wild!</comment>
   <items>
      <item partNum="872-AA">
         <productName>Lawnmower</productName>
         <quantity>1</quantity>
         <USPrice>148.95</USPrice>
         <comment>Confirm this is electric</comment>
      </item>
      <item partNum="926-AA">
         <productName>Baby Monitor</productName>
         <quantity>1</quantity>
         <USPrice>39.98</USPrice>
         <shipDate>1999-05-21</shipDate>
      </item>
   </items>
</purchaseOrder>

The purchase order's elements have simple types or complex types

• the purchase order consists of a main element purchaseOrder and the subelements {shipTo, billTo, comment, items}.
• subelements can contain other subelements or data
• elements that contain subelements or carry attributes are said to have complex types
• elements that contain numbers, strings, dates and no subelements are said to have simple types, attributes always have simple types

Where to find the definitions of the types in the instance document

• the complex types in the instance document are defined in the schema for purchase orders
• the simple types in the instance document are defined either in the schema for purchase orders or are part of the built-in simple types of XML Schema

What is the association between the instance document and the the purchase order schema?

• an instance document does not need to refer to a schema
• the purchase order does not reference the purchase order schema