Estimados codificadores compañero de java, he utilizado un ejemplo de http://www.vogella.com/articles/JAXB/article.html¿Cómo puedo hacer un trabajo de la clase abstracta con JAXB
para el uso de XML JAXB para mis 3 clases, UserStorage, el usuario y UserTest
se funciona bien, pero es sólo el unmarchialing de
JAXBContext context = JAXBContext.newInstance(UserStorage.class);
Marshaller m = context.createMarshaller();
m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
the User class is ABSTRACT!, so it throws an
Excepción en hilo javax.xml.bind.UnmarshalException "principal": No se puede para crear un Instan ce de platform.User - con excepción vinculado: [java.lang.InstantiationException] en com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.handleEvent (UnmarshallingContext.java:648) en com. sun.xml.internal.bind.v2.runtime.unmarshaller.Loader.reportError (Loader.java:236) en com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.createInstance (UnmarshallingContext.java : 615) en com.sun.xml.internal.bind.v2.runtime.unmarshaller.StructureLoader.startElement (StructureLoader.java:170) en com.sun.xml.internal.bind.v2.runtime.unmarshaller .UnmarshallingContext._startElement (UnmarshallingContext.java:487) en com.sun .xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.startElement (UnmarshallingContext.java:465) en com.sun.xml.internal.bind.v2.runtime.unmarshaller.SAXConnector.startElement (SAXConnector.java: 135) en com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement (AbstractSAXParser.java:501) en com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement (XMLNSDocumentScannerImpl.java:400) en com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl $ FragmentContentDriver.next (XMLDocumentFragmentScannerImpl.java:2756) en com.sun.org.apache.xerces.internal. impl.XMLDocumentScannerImpl.next (XMLDocumentScannerImpl.jav a: 648) en com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next (XMLNSDocumentScannerImpl.java:140) en com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl. scanDocument (XMLDocumentFragmentScannerImpl.java:511) en com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse (XML11Configuration.java:808) en com.sun.org.apache.xerces.internal. parsers.XML11Configuration.parse (XML11Configuration.java:737) en com.sun.org.apache.xerces.internal.parsers.XMLParser.parse (XMLParser.java:119) en com.sun.org.apache. xerces.internal.parsers.AbstractSAXParser.parse (AbstractSAXPars er.java:1205) en com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl $ JAXPSAXParser.parse (SAXParserImpl.java:522) en com.sun.xml.internal.bind.v2. runtime.unmarshaller.UnmarshallerImpl.unmarshal0 (UnmarshallerImpl.java:200) en com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal (UnmarshallerImpl.java:173) en javax.xml. bind.helpers.AbstractUnmarshallerImpl.unmarshal (AbstractUnmarshallerImpl.java:137) en javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal (AbstractUnmarshallerImpl.java:194) en platform.UserTest.main (UserTest.java:77) causada por: java.lang.InstantiationException en sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance (InstantiationExceptionConstructorAccessorImpl.java:30) en java.lang.reflect.Constructor.newInstance (Constructor.java:513) en com.sun.xml.internal.bind.v2. ClassFactory.create0 (ClassFactory.java:112) en com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.createInstance (ClassBeanInfoImpl.java:231) en com.sun.xml.internal.bind.v2 .runtime.unmarshaller.UnmarshallingContext.createInstance (UnmarshallingContext.java:609) ... 20 más
¿hay alguna solución para esto , así podría vincular la clase User al XML, ya que puedo guardar el archivo XML con los detalles del usuario, pero es cuando quiero recuperarlo, comprueba que la clase User es abstracta, tengo una subclase admin, broker, accionista , pero hasta ahora, en mi clase de prueba de usuario, he creado solo 4 administradores para probar, gracias y espero que puedan ayudar.
import platform.UserStorage;
import platform.User;
public class UserTest {
private static final String USER_XML = "user2.xml";
public static void main(String[] args) throws JAXBException, IOException {
ArrayList<User> userList = new ArrayList<User>();
// create test users
User user1 = new Admin();
user1.setName("Dave");
user1.setPass("1234");
user1.setDeleted(true);
user1.setBan(false);
userList.add(user1);
User user2 = new Admin();
user2.setName("James");
user2.setPass("1234");
user2.setDeleted(true);
user2.setBan(false);
userList.add(user2);
User user3 = new Admin();
user3.setName("Mike");
user3.setPass("1234");
user3.setDeleted(true);
user3.setBan(false);
userList.add(user3);
// create bookstore, assigning book
UserStorage userstore = new UserStorage();
userstore.setListName("Test List");
userstore.setUserList(userList);
// create JAXB context and instantiate marshaller
JAXBContext context = JAXBContext.newInstance(UserStorage.class);
Marshaller m = context.createMarshaller();
m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
m.marshal(userstore, System.out);
Writer w = null;
try {
w = new FileWriter(USER_XML);
m.marshal(userstore, w);
} finally {
try {
w.close();
} catch (Exception e) {
}
}
// get variables from our xml file, created before
System.out.println();
System.out.println("Output from our XML File: ");
Unmarshaller um = context.createUnmarshaller();
UserStorage userstore2 = (UserStorage) um.unmarshal(new FileReader(
USER_XML));
for (int i = 0; i < userstore2.getUsersList().toArray().length; i++) {
System.out.println("User " + (i + 1) + ": "
+ userstore2.getUsersList().get(i).getName() + " Pass "
+ userstore2.getUsersList().get(i).getPass());
}} }
package platform;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
//If you want you can define the order in which the fields are written
//Optional
/**
* @author dinesh.kaushish, james.wyche //updated XML properties.
*
*/
@XmlRootElement(name = "user")
@XmlType(propOrder = { "name", "pass", "deleted", "ban" })
..
public abstract class User implements UserInterface {
private String name;
private String pass;
private boolean deleted;
private boolean ban;
/**
* @ author dinesh.kaushish
* @param String username
* return void
*/
public void setName(String name)
{
this.name = name;
}
// If you like the variable name, e.g. "name", you can easily change this
// name for your XML-Output:
/**
* @author dinesh.kaushish
* @param null
* @return String user;
*/
@XmlElement(name = "user")
public String getName()
{
return this.name;
}
/**
* @author dinesh.kaushish
* @param String pwd
* @return void
*/
public void setPass(String pass)
{
this.pass=pass;
}
/**
* @author dinesh.kaushish
* @param void
* @return String password
*/
@XmlElement(name = "pass")
public String getPass()
{
return pass;
}
/**
* @author dinesh.kaushish
* @param dFlag
* @return void
*/
public void setDeleted(boolean deleted)
{
this.deleted = deleted;
}
/**
* @author dinesh.kaushish
* @return boolean isDeleted
*/
@XmlElement(name = "deleted")
public boolean getDeleted()
{
return deleted;
}
/**
* @author dinesh.kaushish
* @param bFlag
*/
public void setBan(boolean ban)
{
this.ban = ban;
}
/**
* @author dinesh.kaushish
* @return Boolean isBanned
*/
@XmlElement(name = "ban")
public Boolean getBan()
{
return ban;
}
public abstract void addUser();
public abstract void removeUser();
public abstract void verifyUser();
public abstract void passReset();
public abstract void faultReport();
public abstract void RequestsForAccess();
public abstract void UpdateDetails();
public abstract void BanUser();
public abstract void ChangePermissions();
}
package platform;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.HashMap;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.XMLEvent;
import java.util.ArrayList;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlRootElement;
/**
* @author michael.wambeek, james.wyche //added JAXB support.
*
*/
//This statement means that class "Bookstore.java" is the root-element of our example
@XmlRootElement(namespace = "platform")
public class UserStorage {
// XmLElementWrapper generates a wrapper element around XML representation
@XmlElementWrapper(name = "userList")
// XmlElement sets the name of the entities
@XmlElement(name = "user")
private ArrayList<User> userList;
private String listName = "";
// ejemplo UserStorage estática privada; // fin de james.wyche códigos JAXB.
public UserStorage(){
}
/**
* @author michael.wambeek
*
* Searches for a username and returns the password.
*
* @param username The username to search for
* @return The password of the correct username or null
* @throws Exception
*/
public String findUser(String username) throws Exception{
return search(username);
}
public boolean storeUser(String username, String password, UserType type){
return true;
}
/**
* @author james.wyche
* @param userList
*/
public void setUserList(ArrayList<User> userList) {
this.userList = userList;
}
/**
*
* @return UserList
*/
public ArrayList<User> getUsersList() {
return userList;
}
Adición XmlTransient en la superclase eliminará la relación de herencia, que puede no ser deseado, consulte: http://blog.bdoughan.com/ búsqueda/etiqueta/XmlTransient. El artículo puede ayudar: http://blog.bdoughan.com/2010/11/jaxb-and-inheritance-using-xsitype.html –
gracias, echaremos un vistazo – Sean