Abstract types can only be instantiated with additional type information

[oliv.g...@gmail.com]

Dear All,

I am using MongoJack on a OSGI Stack. Below is the exception I am getting:

set 29, 2015 3:12:59 PM com.mongodb.DBPortPool gotError
ADVERTÊNCIA: emptying DBPortPool to localhost/127.0.0.1:27017 b/c of error
org.codehaus.jackson.map.JsonMappingException: Can not construct instance of api.Book, problem: abstract types can only be instantiated with additional type information
 at [Source: de.undercouch.bson4jackson.io.LittleEndianInputStream@4fe0026c; pos: 0]
    at org.codehaus.jackson.map.JsonMappingException.from(JsonMappingException.java:163)
    at org.codehaus.jackson.map.deser.StdDeserializationContext.instantiationException(StdDeserializationContext.java:233)
    at org.codehaus.jackson.map.deser.AbstractDeserializer.deserialize(AbstractDeserializer.java:60)
    at org.codehaus.jackson.map.ObjectMapper._readValue(ObjectMapper.java:2704)
    at org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:1315)
    at net.vz.mongodb.jackson.internal.stream.JacksonDBDecoder.decode(JacksonDBDecoder.java:62)
    at com.mongodb.Response.<init>(Response.java:83)
    at com.mongodb.DBPort.go(DBPort.java:142)
    at com.mongodb.DBPort.call(DBPort.java:92)
    at com.mongodb.DBTCPConnector.innerCall(DBTCPConnector.java:244)
    at com.mongodb.DBTCPConnector.call(DBTCPConnector.java:216)
    at com.mongodb.DBApiLayer$MyCollection.__find(DBApiLayer.java:288)
    at com.mongodb.DBApiLayer$MyCollection.__find(DBApiLayer.java:273)
    at com.mongodb.DBCursor._check(DBCursor.java:368)
    at com.mongodb.DBCursor._hasNext(DBCursor.java:459)
    at com.mongodb.DBCursor.hasNext(DBCursor.java:484)
    at net.vz.mongodb.jackson.DBCursor.hasNext(DBCursor.java:315)
    at mongo.BookInventoryMongo.listBooks(BookInventoryMongo.java:44)
    at mongo.BookInventoryMongo.start(BookInventoryMongo.java:58)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.apache.felix.dm.InvocationUtil.invokeMethod(InvocationUtil.java:111)
    at org.apache.felix.dm.InvocationUtil.invokeCallbackMethod(InvocationUtil.java:66)
    at org.apache.felix.dm.impl.ComponentImpl.invokeCallbackMethod(ComponentImpl.java:688)
    at org.apache.felix.dm.impl.ComponentImpl.invoke(ComponentImpl.java:679)
    at org.apache.felix.dm.impl.ComponentImpl.bindService(ComponentImpl.java:624)
    at org.apache.felix.dm.impl.ComponentImpl.access$400(ComponentImpl.java:52)
    at org.apache.felix.dm.impl.ComponentImpl$7.run(ComponentImpl.java:181)
    at org.apache.felix.dm.impl.SerialExecutor$1.run(SerialExecutor.java:47)
    at org.apache.felix.dm.impl.SerialExecutor.scheduleNext(SerialExecutor.java:84)
    at org.apache.felix.dm.impl.SerialExecutor.access$000(SerialExecutor.java:33)
    at org.apache.felix.dm.impl.SerialExecutor$1.run(SerialExecutor.java:50)
    at org.apache.felix.dm.impl.SerialExecutor.scheduleNext(SerialExecutor.java:84)
    at org.apache.felix.dm.impl.SerialExecutor.access$000(SerialExecutor.java:33)
    at org.apache.felix.dm.impl.SerialExecutor$1.run(SerialExecutor.java:50)
    at org.apache.felix.dm.impl.SerialExecutor.scheduleNext(SerialExecutor.java:84)
    at org.apache.felix.dm.impl.SerialExecutor.execute(SerialExecutor.java:68)
    at org.apache.felix.dm.impl.ComponentImpl.calculateStateChanges(ComponentImpl.java:231)
    at org.apache.felix.dm.impl.ComponentImpl.start(ComponentImpl.java:399)
    at org.apache.felix.dm.DependencyManager.add(DependencyManager.java:169)
    at mongo.Activator.init(Activator.java:28)
    at org.apache.felix.dm.DependencyActivatorBase.start(DependencyActivatorBase.java:76)
    at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:645)
    at org.apache.felix.framework.Felix.activateBundle(Felix.java:2154)
    at org.apache.felix.framework.Felix.startBundle(Felix.java:2072)
    at org.apache.felix.framework.BundleImpl.start(BundleImpl.java:976)
    at aQute.launcher.Launcher.update(Launcher.java:457)
    at aQute.launcher.Launcher$1.run(Launcher.java:194)
    at java.util.TimerThread.mainLoop(Timer.java:555)
    at java.util.TimerThread.run(Timer.java:505)

WARNING: Invocation of 'start' failed. (com.mongodb.MongoException$Network: Read operation to server localhost/127.0.0.1:27017 failed on database test_booksDB)

Below the code:


********API Bundle******


package api;
public interface Book {
    public String getBookName();
    public void setBookName(String name);
}

package api;
import java.util.List;

public interface BookInventory {
    public void addBook(Book book);
    public List<Book> listBooks();
}




****** Mongo Bundle********



 package mongo;

import org.codehaus.jackson.annotate.JsonCreator;
import org.codehaus.jackson.annotate.JsonProperty;

import api.Book;

public class BookMongo implements Book{

    private String _id;
    private String bookName;
   
    public BookMongo() {
        super();
        // TODO Auto-generated constructor stub
    }
   
    @JsonCreator
    public BookMongo(@JsonProperty ("id") String _id, @JsonProperty ("bName") String bookName) {
        super();
        this._id = _id;
        this.bookName = bookName;
    }


    @JsonProperty("id")
    public String get_id() {
        return _id;
    }

    public void set_id(String _id) {
        this._id = _id;
    }

    @Override
    @JsonProperty("bName")
    public String getBookName() {
        return bookName;
    }

    @Override
    public void setBookName(String name) {
        this.bookName = name;
       
    }


    @Override
    public String toString() {
        return "BookMongo [_id=" + _id + ", bookName=" + bookName + "]";
    }

}

package mongo;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import net.vz.mongodb.jackson.DBCursor;
import net.vz.mongodb.jackson.JacksonDBCollection;

import org.amdatu.mongo.MongoDBService;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.annotate.JsonDeserialize;

import com.mongodb.DBCollection;

import api.Book;
import api.BookInventory;

public class BookInventoryMongo implements BookInventory{

    private volatile MongoDBService mongoDBService;
   
    @Override
    public void addBook(Book book) {
   
        DBCollection collection = mongoDBService.getDB().getCollection("booksColl");
        JacksonDBCollection<Book, Object> books = JacksonDBCollection.wrap(collection, Book.class);
        addBook
        books.save(book);
       
    }

    @Override
    @JsonDeserialize(contentAs=BookMongo.class)   
    public List<Book> listBooks() {
       
       
        DBCollection collection = mongoDBService.getDB().getCollection("booksColl");
        JacksonDBCollection<Book, Object> books = JacksonDBCollection.wrap(collection, Book.class);
       
        DBCursor<Book> cursor = books.find();
       
        List<Book> result = new ArrayList<Book>();
        while (cursor.hasNext()) {
            result.add(cursor.next());
        }

        return result;
       
    }
   
    public void start(){   
       
        Book bm = new BookMongo("5","The walking dead");
        addBook(bm);
        System.out.println("****Attention***");
        System.out.println("New book added to mongo");
        System.out.println(listBooks().toString());
    }

}


package mongo;

import java.util.Properties;

import org.amdatu.mongo.MongoDBService;
import org.apache.felix.dm.DependencyActivatorBase;
import org.apache.felix.dm.DependencyManager;
import org.osgi.framework.BundleContext;

import api.BookInventory;

public class Activator extends DependencyActivatorBase{

    @Override
    public void destroy(BundleContext arg0, DependencyManager arg1)
            throws Exception {
        // TODO Auto-generated method stub
       
    }

    @Override
    public void init(BundleContext arg0, DependencyManager dm)
            throws Exception {
       
        Properties props = new Properties();
        props.put("persistent", true);
       
    dm.add(createComponent()
            .setInterface(BookInventory.class.getName(), props)
            .setImplementation(BookInventoryMongo.class)
            .add(createServiceDependency()
                    .setService(MongoDBService.class).
                    setRequired(true)));
       
    }

}


It is clear for me that the problem is due to the impossibility of mongo-jackson-mapper reading from the bank. it cannot instantiate the "Book.class" once it is an interface.
I cannot anotate any of the api interfaces otherwise it would broke modularity.  In my research I thought MixIns should be the more suitable option here, however it didnt work at all. I mitgh be doing something wrong definetely. Is there any option to solve this? By the way, the addBook method in BookInventoryMongo works fine.

Than you for helpping.