親愛なる Java コーダーの皆さん、私はhttp://www.vogella.com/articles/JAXB/article.htmlの例を使用しました。
私の 3 つのクラス、UserStorage、User、および UserTest の JAXB XML の使用について
それは正常に動作しますが、それはただの非武装化です
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
スレッド「メイン」での例外 javax.xml.bind.UnmarshalException: platform.User のインスタンスを作成できません - リンクされた例外: [java.lang.InstantiationException] at com.sun.xml.internal.bind.v2.runtime. unmarshaller.UnmarshallingContext.handleEvent(UnmarshallingContext.java:648) at com.sun.xml.internal.bind.v2.runtime.unmarshaller.Loader.reportError(Loader.java:236) at com.sun.xml.internal.bind. v2.runtime.unmarshaller.UnmarshallingContext.createInstance(UnmarshallingContext.java:615) at com.sun.xml.internal.bind.v2.runtime.unmarshaller.StructureLoader.startElement(StructureLoader.java:170) at com.sun.xml. internal.bind.v2.runtime.unmarshaller.UnmarshallingContext._startElement(UnmarshallingContext.java:487) com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.com.sun.org.apache.xerces.internal.parsers の com.sun.xml.internal.bind.v2.runtime.unmarshaller.SAXConnector.startElement(SAXConnector.java:135) の startElement(UnmarshallingContext.java:465)。 AbstractSAXParser.startElement(AbstractSAXParser.java:501) com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:400) com.sun.org.apache.xerces.internal.impl. XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2756) com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:648) com.sun.org.apache.xerces.internal. impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:140) com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:808) の scanDocument(XMLDocumentFragmentScannerImpl.java:511) com.sun.org.apache.xerces.internal.parsers.XML11Configuration. com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:119) の parse(XML11Configuration.java:737) com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser. parse(AbstractSAXParser.java:1205) com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:522) com.sun.xml.internal.bind.v2.runtime. unmarshaller.UnmarshallerImpl.unmarshall0(UnmarshallerImpl.java:200) at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:173) at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:137) at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:194) platform.UserTest.main(UserTest.java:77) 原因: java.lang.InstantiationException at sun .reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:30) で java.lang.reflect.Constructor.newInstance(Constructor.java:513) で com.sun.xml.internal.bind.v2.ClassFactory.create0(ClassFactory.java) :112) com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.createInstance(ClassBeanInfoImpl.java:231) で com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.createInstance(UnmarshallingContext) で.java:609) ... 20 件以上AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:194) at platform.UserTest.main(UserTest.java:77) 原因: java.lang.InstantiationException at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:30) at java.lang .reflect.Constructor.newInstance(Constructor.java:513) で com.sun.xml.internal.bind.v2.ClassFactory.create0(ClassFactory.java:112) で com.sun.xml.internal.bind.v2.runtime .ClassBeanInfoImpl.createInstance(ClassBeanInfoImpl.java:231) at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.createInstance(UnmarshallingContext.java:609) ... 20 以上AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:194) at platform.UserTest.main(UserTest.java:77) 原因: java.lang.InstantiationException at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:30) at java.lang .reflect.Constructor.newInstance(Constructor.java:513) で com.sun.xml.internal.bind.v2.ClassFactory.create0(ClassFactory.java:112) で com.sun.xml.internal.bind.v2.runtime .ClassBeanInfoImpl.createInstance(ClassBeanInfoImpl.java:231) at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.createInstance(UnmarshallingContext.java:609) ... 20 以上com.sun.xml.internal.bind.v2.ClassFactory.create0(ClassFactory.java:112) の java.lang.reflect.Constructor.newInstance(Constructor.java:513) で InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:30) com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.createInstance(ClassBeanInfoImpl.java:231) で com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.createInstance(UnmarshallingContext.java: 609) ... 20以上com.sun.xml.internal.bind.v2.ClassFactory.create0(ClassFactory.java:112) の java.lang.reflect.Constructor.newInstance(Constructor.java:513) で InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:30) com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.createInstance(ClassBeanInfoImpl.java:231) で com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.createInstance(UnmarshallingContext.java: 609) ... 20以上createInstance(ClassBeanInfoImpl.java:231) at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.createInstance(UnmarshallingContext.java:609) ... 20 詳細createInstance(ClassBeanInfoImpl.java:231) at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.createInstance(UnmarshallingContext.java:609) ... 20 詳細
これに対する解決策はありますか?ユーザーの詳細を含む XML ファイルを保存できるので、ユーザー クラスを XML にバインドできますが、それを取得したいときは、ユーザー クラスが抽象的であると不平を言います。管理者がいます、ブローカー、株主のサブクラスですが、これまでのところ、私のユーザー テスト クラスでは、テストする管理者を 4 人だけ作成しました。
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 = "";
// プライベートな静的 UserStorage インスタンス; // james.wyche JAXB コードの終わり。
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;
}