Binding XML Schemas

This section describes the default XML-to-Java bindings used by JAXB. All of these bindings can be overridden on global or case-by-case levels by means of a custom binding declaration. See the JAXB Specification for complete information about the default JAXB bindings.

Simple Type Definitions

A schema component using a simple type definition typically binds to a Java property. Since there are different kinds of such schema components, the following Java property attributes (common to the schema components) include:

• Base type

• Collection type, if any

• Predicate

The rest of the Java property attributes are specified in the schema component using the simple type definition.

Default Data Type Bindings

The following sections explain the default schema-to-Java, JAXBElement, and Java-to-schema data type bindings.

Schema-to-Java Mapping

The Java language provides a richer set of data type than XML schema. Table 17–1 lists the mapping of XML data types to Java data types in JAXB.

Table 17–1 JAXB Mapping of XML Schema Built-in Data Types

XML Schema Type	Java Data Type
xsd:string	java.lang.String
xsd:integer	java.math.BigInteger
xsd:int	int
xsd.long	long
xsd:short	short
xsd:decimal	java.math.BigDecimal
xsd:float	float
xsd:double	double
xsd:boolean	boolean
xsd:byte	byte
xsd:QName	javax.xml.namespace.QName
xsd:dateTime	javax.xml.datatype.XMLGregorianCalendar
xsd:base64Binary	byte[]
xsd:hexBinary	byte[]
xsd:unsignedInt	long
xsd:unsignedShort	int
xsd:unsignedByte	short
xsd:time	javax.xml.datatype.XMLGregorianCalendar
xsd:date	javax.xml.datatype.XMLGregorianCalendar
xsd:g	javax.xml.datatype.XMLGregorianCalendar
xsd:anySimpleType	java.lang.Object
xsd:anySimpleType	java.lang.String
xsd:duration	javax.xml.datatype.Duration
xsd:NOTATION	javax.xml.namespace.QName

JAXBElement Object

When XML element information can not be inferred by the derived Java representation of the XML content, a JAXBElement object is provided. This object has methods for getting and setting the object name and object value.

Java-to-Schema Mapping

Table 17–2 shows the default mapping of Java classes to XML data types.

Table 17–2 JAXB Mapping of XML Data Types to Java Classes

Java Class	XML Data Type
java.lang.String	xs:string
java.math.BigInteger	xs:integer
java.math.BigDecimal	xs:decimal
java.util.Calendar	xs:dateTime
java.util.Date	xs:dateTime
javax.xml.namespace.QName	xs:QName
java.net.URI	xs:string
javax.xml.datatype.XMLGregorianCalendar	xs:anySimpleType
javax.xml.datatype.Duration	xs:duration
java.lang.Object	xs:anyType
java.awt.Image	xs:base64Binary
javax.activation.DataHandler	xs:base64Binary
javax.xml.transform.Source	xs:base64Binary
java.util.UUID	xs:string