How Does JAXB Compare to XMLBeans?
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Join For FreeIn previous posts I compared JAXB (JSR-222) to Simple and XStream when starting from Java objects. In this post I'll compare JAXB to XMLBeans when starting from an XML schema. I will use XMLBeans 2.5.0 (December 2009) which is the latest release.
<?xml version="1.0" encoding="UTF-8"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="http://www.example.com" targetNamespace="http://www.example.com" elementFormDefault="qualified"> <xs:element name="customer"> <xs:complexType> <xs:sequence> <xs:element name="name" type="xs:string"/> <xs:element name="address" type="address"/> <xs:element name="phone-number" type="phone-number" minOccurs="0" maxOccurs="unbounded"/> </xs:sequence> </xs:complexType> </xs:element> <xs:complexType name="address"> <xs:sequence> <xs:element name="street" type="xs:string"/> <xs:element name="city" type="xs:string"/> </xs:sequence> </xs:complexType> <xs:complexType name="phone-number"> <xs:simpleContent> <xs:extension base="xs:string"> <xs:attribute name="type" type="xs:string"/> </xs:extension> </xs:simpleContent> </xs:complexType> </xs:schema>
1 | scomp -d out -srconly customer.xsd |
Below are all the artifacts that are generated by XMLBeans. The XML Schema Binary (XSB) files contain metadata need to perform binding and validation:
- com/example
- Address.java
- CustomerDocument.java
- PhoneNumber.java
- com/example/impl
- AddressImpl.java
- CustomerDocumentImpl.java
- PhoneNumberImpl.java
- schemaorg_apache_xmlbeans
- element/http_3A_2F_2Fwww_2Eexample_2Ecom
- customer.xsb
- javaname/com/example
- Address.xsb
- CustomerDocument.xsb
- PhoneNumber.xsb
-
- CustomerDocument
- Customer.xsb
- CustomerDocument
- namespace/http_3A_2F_2Fwww_2Eexample_2Ecom
- xmlns.xsb
- src
- customer.xsd
- system/s16C99350D7D3A2544A7BFD5E35CA8BC8
- address6f49type.xsb
- customer3fdddoctype.xsb
- customer11d7elemtype.xsb
- customerelement.xsb
- index.xsb
- phonenumber9c83type.xsb
- TypeSystemHolder.class
- type/http_3A_2F_2Fwww_2Eexample_2Ecom
- address.xsb
- phone_2Dnumber.xsb
- element/http_3A_2F_2Fwww_2Eexample_2Ecom
1 | xjc -d out customer.xsd |
Below are all the artifacts that are generated by JAXB. Note how many fewer artifacts are created:
- com.example
- Address.java
- Customer.java
- ObjectFactory.java
- package-info.java
- PhoneNumber.java
Java Model - XMLBeans
XMLBeans produces a set of Java interfaces that are backed by implementation classes. Below we will examine one of these pairs.
This is one of the interfaces that is generated by XMLBeans. There are a few interesting things worth noting:
- This interface exposes POJO properties (line 24), and a DOM like model (line 29).
- This interface includes a factory (line 66). This factory is used for creating instances of the Address object (line 68), and for unmarshalling instances of Address from XML (line 75).
package com.example; /** * An XML address(@http://www.example.com). * * This is a complex type. */ public interface Address extends org.apache.xmlbeans.XmlObject { public static final org.apache.xmlbeans.SchemaType type = (org.apache.xmlbeans.SchemaType) org.apache.xmlbeans.XmlBeans.typeSystemForClassLoader(Address.class.getClassLoader(), "schemaorg_apache_xmlbeans.system.s16C99350D7D3A2544A7BFD5E35CA8BC8").resolveHandle("address6f49type"); /** * Gets the "street" element */ java.lang.String getStreet(); /** * Gets (as xml) the "street" element */ org.apache.xmlbeans.XmlString xgetStreet(); /** * Sets the "street" element */ void setStreet(java.lang.String street); /** * Sets (as xml) the "street" element */ void xsetStreet(org.apache.xmlbeans.XmlString street); /** * Gets the "city" element */ java.lang.String getCity(); /** * Gets (as xml) the "city" element */ org.apache.xmlbeans.XmlString xgetCity(); /** * Sets the "city" element */ void setCity(java.lang.String city); /** * Sets (as xml) the "city" element */ void xsetCity(org.apache.xmlbeans.XmlString city); /** * A factory class with static methods for creating instances * of this type. */ public static final class Factory { public static com.example.Address newInstance() { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().newInstance( type, null ); } public static com.example.Address newInstance(org.apache.xmlbeans.XmlOptions options) { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().newInstance( type, options ); } /** @param xmlAsString the string value to parse */ public static com.example.Address parse(java.lang.String xmlAsString) throws org.apache.xmlbeans.XmlException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( xmlAsString, type, null ); } public static com.example.Address parse(java.lang.String xmlAsString, org.apache.xmlbeans.XmlOptions options) throws org.apache.xmlbeans.XmlException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( xmlAsString, type, options ); } /** @param file the file from which to load an xml document */ public static com.example.Address parse(java.io.File file) throws org.apache.xmlbeans.XmlException, java.io.IOException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( file, type, null ); } public static com.example.Address parse(java.io.File file, org.apache.xmlbeans.XmlOptions options) throws org.apache.xmlbeans.XmlException, java.io.IOException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( file, type, options ); } public static com.example.Address parse(java.net.URL u) throws org.apache.xmlbeans.XmlException, java.io.IOException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( u, type, null ); } public static com.example.Address parse(java.net.URL u, org.apache.xmlbeans.XmlOptions options) throws org.apache.xmlbeans.XmlException, java.io.IOException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( u, type, options ); } public static com.example.Address parse(java.io.InputStream is) throws org.apache.xmlbeans.XmlException, java.io.IOException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( is, type, null ); } public static com.example.Address parse(java.io.InputStream is, org.apache.xmlbeans.XmlOptions options) throws org.apache.xmlbeans.XmlException, java.io.IOException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( is, type, options ); } public static com.example.Address parse(java.io.Reader r) throws org.apache.xmlbeans.XmlException, java.io.IOException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( r, type, null ); } public static com.example.Address parse(java.io.Reader r, org.apache.xmlbeans.XmlOptions options) throws org.apache.xmlbeans.XmlException, java.io.IOException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( r, type, options ); } public static com.example.Address parse(javax.xml.stream.XMLStreamReader sr) throws org.apache.xmlbeans.XmlException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( sr, type, null ); } public static com.example.Address parse(javax.xml.stream.XMLStreamReader sr, org.apache.xmlbeans.XmlOptions options) throws org.apache.xmlbeans.XmlException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( sr, type, options ); } public static com.example.Address parse(org.w3c.dom.Node node) throws org.apache.xmlbeans.XmlException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( node, type, null ); } public static com.example.Address parse(org.w3c.dom.Node node, org.apache.xmlbeans.XmlOptions options) throws org.apache.xmlbeans.XmlException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( node, type, options ); } /** @deprecated {@link org.apache.xmlbeans.xml.stream.XMLInputStream} */ public static com.example.Address parse(org.apache.xmlbeans.xml.stream.XMLInputStream xis) throws org.apache.xmlbeans.XmlException, org.apache.xmlbeans.xml.stream.XMLStreamException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( xis, type, null ); } /** @deprecated {@link org.apache.xmlbeans.xml.stream.XMLInputStream} */ public static com.example.Address parse(org.apache.xmlbeans.xml.stream.XMLInputStream xis, org.apache.xmlbeans.XmlOptions options) throws org.apache.xmlbeans.XmlException, org.apache.xmlbeans.xml.stream.XMLStreamException { return (com.example.Address) org.apache.xmlbeans.XmlBeans.getContextTypeLoader().parse( xis, type, options ); } /** @deprecated {@link org.apache.xmlbeans.xml.stream.XMLInputStream} */ public static org.apache.xmlbeans.xml.stream.XMLInputStream newValidatingXMLInputStream(org.apache.xmlbeans.xml.stream.XMLInputStream xis) throws org.apache.xmlbeans.XmlException, org.apache.xmlbeans.xml.stream.XMLStreamException { return org.apache.xmlbeans.XmlBeans.getContextTypeLoader().newValidatingXMLInputStream( xis, type, null ); } /** @deprecated {@link org.apache.xmlbeans.xml.stream.XMLInputStream} */ public static org.apache.xmlbeans.xml.stream.XMLInputStream newValidatingXMLInputStream(org.apache.xmlbeans.xml.stream.XMLInputStream xis, org.apache.xmlbeans.XmlOptions options) throws org.apache.xmlbeans.XmlException, org.apache.xmlbeans.xml.stream.XMLStreamException { return org.apache.xmlbeans.XmlBeans.getContextTypeLoader().newValidatingXMLInputStream( xis, type, options ); } private Factory() { } // No instance of this class allowed } }
Below is the source for the implementation class:
JAXB implementations produce annotated POJOs. The generated classes closely resemble the ones we created by hand in the comparisons to Simple and XStream.
// // This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.10 in JDK 6 // See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a> // Any modifications to this file will be lost upon recompilation of the source schema. // Generated on: 2012.01.23 at 01:19:09 PM EST // package com.example; import javax.xml.bind.annotation.XmlAccessType; import javax.xml.bind.annotation.XmlAccessorType; import javax.xml.bind.annotation.XmlElement; import javax.xml.bind.annotation.XmlType; /** * <p>Java class for address complex type. * * <p>The following schema fragment specifies the expected content contained within this class. * * <pre> * <complexType name="address"> * <complexContent> * <restriction base="{http://www.w3.org/2001/XMLSchema}anyType"> * <sequence> * <element name="street" type="{http://www.w3.org/2001/XMLSchema}string"/> * <element name="city" type="{http://www.w3.org/2001/XMLSchema}string"/> * </sequence> * </restriction> * </complexContent> * </complexType> * </pre> * * */ @XmlAccessorType(XmlAccessType.FIELD) @XmlType(name = "address", propOrder = { "street", "city" }) public class Address { @XmlElement(required = true) protected String street; @XmlElement(required = true) protected String city; /** * Gets the value of the street property. * * @return * possible object is * {@link String } * */ public String getStreet() { return street; } /** * Sets the value of the street property. * * @param value * allowed object is * {@link String } * */ public void setStreet(String value) { this.street = value; } /** * Gets the value of the city property. * * @return * possible object is * {@link String } * */ public String getCity() { return city; } /** * Sets the value of the city property. * * @param value * allowed object is * {@link String } * */ public void setCity(String value) { this.city = value; } }
In the demo code we will unmarshal an XML file, add a phone number to the resulting customer object, and then marshal the customer back to XML.
With XMLBeans the generated domain model is used to unmarshal (line 12) and marshal (line 19). The generated model also contains methods for interacting with collections (line 15), this is necessary as XMLBeans represent collection properties as arrays.
package com.example; import java.io.File; import com.example.CustomerDocument.Customer; public class Demo { public static void main(String[] args) throws Exception { File xml = new File("src/com/example/input.xml"); CustomerDocument customerDocument = CustomerDocument.Factory.parse(xml); Customer customer = customerDocument.getCustomer(); PhoneNumber homePhoneNumber = customer.addNewPhoneNumber(); homePhoneNumber.setType("home"); homePhoneNumber.set("555-HOME"); customerDocument.save(System.out); } }
package com.example; import java.io.File; import javax.xml.bind.*; public class Demo { public static void main(String[] args) throws Exception { JAXBContext jc = JAXBContext.newInstance("com.example"); File xml = new File("src/com/example/input.xml"); Unmarshaller unmarshaller = jc.createUnmarshaller(); Customer customer = (Customer) unmarshaller.unmarshal(xml); PhoneNumber homePhoneNumber = new PhoneNumber(); homePhoneNumber.setType("home"); homePhoneNumber.setValue("555-HOME"); customer.getPhoneNumber().add(homePhoneNumber); Marshaller marshaller = jc.createMarshaller(); marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); marshaller.marshal(customer, System.out); } }
- JPA annotations could easily be applied to the JAXB model enabling the model to be persisted in a relational database.
- Once generated the JAXB model could be modified to handle changes in the XML schema, the XMLBeans model would need to be regenerated.
- Starting with Java SE 6 no additional compile/runtime dependencies are required for the JAXB model.
- There are multiple JAXB implementations available: EclipseLink MOXy, Metro, Apache JaxMe, etc.
- JAXB is the standard binding layer for JAX-WS (SOAP) and JAX-RS (RESTful) Web Services.
From http://blog.bdoughan.com/2012/01/how-does-jaxb-compare-to-xmlbeans.html
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