Jackson JSON - problem z serializacja klasy

package com.m.jackson_samples;

import java.io.File;
import java.io.IOException;

import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;

public class Main {
	public static void main(String[] args) throws JsonGenerationException, JsonMappingException, IOException {
		ObjectMapper mapper = new ObjectMapper();
		PlainMessage msg = new PlainMessage("Wiadomosc", "Pewna wiadomosc");
		
		// write JSON from java object
		mapper.writeValue(new File("E:\\msg.json"), msg);
		
		// convert JSON to java object
                // w tej linijce sie wywala
		PlainMessage n = mapper.readValue("E:\\msg.json", PlainMessage.class);
	}
}

package com.m.jackson_samples;

public abstract class MessangerData {
	protected int id;

	MessangerData(int id) {
		this.id = id;
	}
	
 	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}
}

package com.m.jackson_samples;

public class PlainMessage extends MessangerData {
	protected String author;
	protected String content;
	
	PlainMessage(String author, String content) {
		super(1);
		this.author = author;
		this.content = content;
	}
	
	public String getAuthor() {
		return author;
	}
	public void setAuthor(String author) {
		this.author = author;
	}
	public String getContent() {
		return content;
	}
	public void setContent(String content) {
		this.content = content;
	}	
}

Exception in thread "main" com.fasterxml.jackson.core.JsonParseException: Unexpected character ('E' (code 69)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')
 at [Source: java.io.StringReader@7a8a44a6; line: 1, column: 2]
	at com.fasterxml.jackson.core.JsonParser._constructError(JsonParser.java:1378)
	at com.fasterxml.jackson.core.base.ParserMinimalBase._reportError(ParserMinimalBase.java:599)
	at com.fasterxml.jackson.core.base.ParserMinimalBase._reportUnexpectedChar(ParserMinimalBase.java:520)
	at com.fasterxml.jackson.core.json.ReaderBasedJsonParser._handleUnexpectedValue(ReaderBasedJsonParser.java:1387)
	at com.fasterxml.jackson.core.json.ReaderBasedJsonParser.nextToken(ReaderBasedJsonParser.java:678)
	at com.fasterxml.jackson.databind.ObjectMapper._initForReading(ObjectMapper.java:2834)
	at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:2781)
	at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:1942)
	at com.margor.jackson_samples.Main.main(Main.java:19)

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

public class PlainMessage extends MessangerData {
	protected String author;
	protected String content;
	
	@JsonCreator
	PlainMessage(@JsonProperty("id") String id, @JsonProperty("author") String author, @JsonProperty("content") String content) {
		super(Integer.parseInt(id));
		this.author = author;
		this.content = content;
	}
	
	PlainMessage(String author, String content) {
		super(1);
		this.author = author;
		this.content = content;
	}
	
	public String getAuthor() {
		return author;
	}
	public void setAuthor(String author) {
		this.author = author;
	}
	public String getContent() {
		return content;
	}
	public void setContent(String content) {
		this.content = content;
	}	
}

package com.margor.jackson_samples;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

public class GoodByeMessage extends MessangerData {
	private final String BYE_MSG;
	
	@JsonCreator
	GoodByeMessage(@JsonProperty("id") String id, @JsonProperty("_BYE_MSG") String BYE_MSG) {
		super(Integer.parseInt(id));
		this.BYE_MSG = BYE_MSG;
	}
	
	GoodByeMessage() {
		super(2);
		BYE_MSG = "Good bye!";
	}

	public String get_BYE_MSG() {
		return BYE_MSG;
	}
}

PlainMessage n = mapper.readValue(new File("E:\\msg.json"), PlainMessage.class);

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type")
@JsonSubTypes({
    @Type(value = PlainMessage.class),
    @Type(value = GoodByeMessage.class)})
public abstract class MessangerData {...}

@JsonTypeName("Plain")
public class PlainMessage extends MessangerData {...}

@JsonTypeName("GoodBye")
public class GoodByeMessage extends MessangerData {...}