Java JAXB JavaBean and XML interoperability

1.jaxb-java arcitecture for XML Binding

is a standard in the industry and is a technology that can generate Java classes based on XML schemas.

Jaxb2.0 is an integral part of Jdk1.6. The conversion of XML to JavaBean is done without the support of a third-party jar package.

2. Key Concepts:

· The Jaxbcontext class, which is the application's portal, is used to manage Xml/java binding information.

· The Marshaller interface, which serializes Java objects into XML data.

· Unmarshaller interface that deserializes XML data into Java objects.

• @XmlType to map a Java class or enumeration type to an XML Schema type

• @XmlAccessorType (Xmlaccesstype.field) to control the serialization of fields or properties. field indicates that JAXB will automatically bind each non-static, non-instantaneous (denoted by @xmltransient) field in the Java class to the

Xml. Other values are Xmlaccesstype.property and Xmlaccesstype.none.

• @XmlAccessorOrder to control the ordering of properties and fields in the JAXB binding class.

· Xmljavatypeadapter, using custom adapters (that is, extending the abstract class XMLAdapter and overriding the Marshal () and Unmarshal () methods) to serialize the Java class as XML

• @XmlElementWrapper, for arrays and collections (that is, member variables that contain multiple elements), generates an XML element that wraps the array and binds it (called the wrapper)

• @XmlRootElement to map a Java class or enumeration type to an XML element.

• @XmlElement to map an attribute in a Java class to an XML element with the same name as the property.

• @XmlAttribute, Map a property of a Java class to an XML attribute with the same name as the property.

3. Application:

The use of JAXB is very simple, as follows is a code I write, through the Util class to complete the conversion between JavaBean and XML

Jaxbutil class: responsible for the transit with JAXB:

public class Jaxbutil {

public static String converttoxml (Object obj) {

return Converttoxml (obj, "UTF-8");

}

/**
* @note JavaBean to XML
* @param obj
* JavaBean
* @param encoding
* Code
* @return XML
*/

public static string Converttoxml (Object obj, string encoding) {

String result = null;

try {

Jaxbcontext context = Jaxbcontext.newinstance (Obj.getclass ());

Marshaller Marshaller = Context.createmarshaller ();

Marshaller.setproperty (Marshaller.jaxb_formatted_output, true);

Marshaller.setproperty (marshaller.jaxb_encoding, ENCODING);

StringWriter writer = new StringWriter ();

Marshaller.marshal (obj, writer);

result = Writer.tostring ();

} catch (Exception ex) {

}

return result;

}

/**
* @note XML to JavaBean
* @param xml
*Xml
* @param c
*Javbean
* @return
*/

public static <T> T Converttojavabean (String XML, class<t> c) {

T t = null;

try {

Jaxbcontext context = Jaxbcontext.newinstance (c);

Unmarshaller Unmarshaller = Context.createunmarshaller ();

t = (t) Unmarshaller.unmarshal (new StringReader (XML));

} catch (Exception ex) {

Ex.printstacktrace ();

}

return t;

}

}

Simple class: An easy bean object, where the main method is to test it

@XmlAccessorType (Xmlaccesstype.field)

@XmlRootElement

@XmlType (name = "Boook", Proporder = {"Author", "Calendar", "Price", "id"})

public class Simple {

@XmlElement (required = true)

Private String author;

@XmlElement (name= "price_l", Required=true)

private float price;

@XmlElement

Private Date Calendar;

@XmlElement

Private Integer ID;

Public String Getauthor () {

return author;

}

public void Setauthor (String author) {

This.author = author;

}

public float GetPrice () {

return price;

}

public void Setprice (float price) {

This.price = Price;

}

Public Date Getcalendar () {

return calendar;

}

public void Setcalendar (Date calendar) {

This.calendar = Calendar;

}

Public Integer getId () {

return ID;

}

public void SetId (Integer id) {

This.id = ID;

}

public static void Main (string[] agrs) {

Simple simple = new simple ();

Simple.setid (100);

Simple.setauthor ("WANGBC");

Simple.setcalendar (New Date ());

Simple.setprice (23.45f);

String str = jaxbutil.converttoxml (simple);

System.out.println (str);

}

}

Collect class: a more complex bean object, where the main method is the test of it

@XmlAccessorType (Xmlaccesstype.field)

@XmlRootElement (name = "Hard")

@XmlType (Proporder = {"Name", "Provincelist"})

public class Collect {

@XmlElement (name = "Country_name")

private String name;

@XmlElementWrapper (name = "Provinces")

@XmlElement (name = "province")

Private list<province> provincelist;

Public String GetName () {

return name;

}

public void SetName (String name) {

THIS.name = name;

}

Public list<province> getprovincelist () {

return provincelist;

}

public void Setprovincelist (list<province> provincelist) {

This.provincelist = provincelist;

}

public static void Main (string[] args) {

Collect con = new Collect ();

Con.setname ("China");

list<province> list = new arraylist<province> ();

Province Pro = new province ();

Pro.setname ("Jiangsu province");

Pro.setprovcity ("Nanjing");

Province Pro2 = new province ();

Pro2.setname ("Zhejiang province");

Pro2.setprovcity ("Hangzhou city");

List.add (PRO);

List.add (PRO2);

Con.setprovincelist (list);

String str = Jaxbutil.converttoxml (con);

System.out.println (str);

}

}

@XmlAccessorType (Xmlaccesstype.field)

@XmlType (Proporder = {"Name", "Provcity"})

Class Province {

@XmlElement (name = "Province_name")

private String name;

@XmlElement (name = "Prov_city")

Private String provcity;

Public String GetName () {
return name;

}

public void SetName (String name) {

THIS.name = name;

}

Public String getprovcity () {

return provcity;

}

public void setprovcity (String provcity) {

this.provcity = provcity;

}

}
As with the conversion between JavaBean and XML, JAXB is relatively simple to use, and JAXB does not need to introduce a third-party jar to rely on, and the implementation is entirely up to the JDK.

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Java JAXB JavaBean and XML interoperability