XMLEncoder: discarding statement ArrayList.add

[lsbill]

I am trying to serialize an object that contains an ArrayList as part of the object. However, I keep getting an error:

Writing Race
java.lang.InstantiationException: com.longswordllc.testEncoder.structs$Car
Continuing ...
java.lang.Exception: XMLEncoder: discarding statement ArrayList.add(structs$Car);
Continuing ...

Here is my code:

structs.java

package com.longswordllc.testEncoder;

public class structs {
	
	public structs() {
		
	}
	
	public class Car {
		private String color;
		
		public Car() {
			color = null;
		}
		
		public String getColor() {
			return color;
		}
		
		public void setColor(String c) {
			color = c;
		}
	}
}

Race.java

package com.longswordllc.testEncoder;

import java.util.ArrayList;
import com.longswordllc.testEncoder.structs.Car;

public class Race {
	private ArrayList<Car> texasRace;
	
	public Race() {
		
	}
	
	public ArrayList<Car> getRace() {
		return texasRace;
	}
	
	public void setRace(ArrayList<Car> a) {
		texasRace = a;
	}
}

mainClass.java

package com.longswordllc.testEncoder;

import java.beans.XMLEncoder;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;

import com.longswordllc.testEncoder.structs.*;

public class mainClass {

	public static void main(String[] args) {
		structs myStructs = new structs();
		Race myRace = new Race();
		Car myCar = myStructs.new Car();
		myCar.setColor("Blue");
		
		ArrayList<Car> someCars = new ArrayList<Car>();
		someCars.add(myCar);
		myRace.setRace(someCars);
		
		System.out.println("Writing Race");
		
		// XML Encode the race object
		try {		
			XMLEncoder encoder = new XMLEncoder(new BufferedOutputStream( new FileOutputStream("race.xml")));
			encoder.writeObject(myRace);
			encoder.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}

And here is the resulting xml code:

<?xml version="1.0" encoding="UTF-8"?>
-<java class="java.beans.XMLDecoder" version="1.6.0_31"> -<object class="com.longswordllc.testEncoder.Race"> -<void property="race"> <object class="java.util.ArrayList"/> </void> </object> </java>

I have tried to ensure i use getter/setters and no argument constructors. not sure what i am missing.

I am still kind of new to serializing. Thanks in advance for any help. I have been stumped for days.

[lsbill]

I fixed it! I had to get rid of the structs class and make it the race class. Then pull the Car class into it's own class file. a few changes to the mainClass and it work. Here is updated code that shows how to make it work. Not sure why it works, though. Im still a new guy to java.

Car Class

package com.longswordllc.testEncoder;

public class Car{
	private String color;
	
	public String getColor() {
		return color;
	}
	
	public void setColor(String c) {
		color = c;
	}
}

Race Class

package com.longswordllc.testEncoder;

import java.util.List;

public class Race {
	private List<Car> myCars;

	public List<Car> getCars() {
		return myCars;
	}
	
	public void setCars(List<Car> data) {
		myCars = data;
	}
}

mainClass class

package com.longswordllc.testEncoder;

import java.beans.XMLEncoder;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class mainClass {

	public static void main(String[] args) {
		Car myCar = new Car();
		myCar.setColor("Blue");
		Car aCar = new Car();
		aCar.setColor("Red");
		
		List<Car> texasRace = new ArrayList<Car>();
		texasRace.add(myCar);
		texasRace.add(aCar);
		
		Race myRace = new Race();
		myRace.setCars(texasRace);
		
		System.out.println("Writing Race");
		
		// XML Encode the race object
		try {		
			XMLEncoder encoder = new XMLEncoder(new BufferedOutputStream( new FileOutputStream("race.xml")));
			encoder.writeObject(texasRace);
			encoder.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}