BlueJ解除引用错误

Question

我正在参加香港科技大学edX的课程。在一项任务中，我制作了一个程序来播放Rock，Paper，Scissors。 在那里，当我去比较选择时，我得到一个编译错误'int不能被解除引用'

import comp102x.ColorImage;
import comp102x.IO;
import comp102x.Canvas; 

/**
 * The Choice class represents a choice made by the player or the computer.
 * It can be either "rock", "paper", or "scissors".
 */
public class Choice
{
    private int type; //stores the choice type: 0=rock, 1=paper, 2=scissors

/**
 * The constructor
 * 
 * @param   type   the choice type to be represented by this Choice object
 */
public Choice(int type)
{
    //initialize the "type" instance varialble
    this.type = type;
}

/**
 * Get a number that represents the choice type
 * 
 * @return  a number that represents the choice type: 0=rock, 1=paper, 2=scissors
 */
public int getType()
{
    return type;
}

/**
 * Compare "this" with anotherChoice
 * 
 * @param   anotherChoice   the choice to be compared
 * @return  either 1, -1, or 0 which indicates the comparison result: 1 means "this" wins anotherChoice; -1 means "this" loses to anotherChoice; 0 means "this" and anotherChoice are the same
 */
public int compareWith(Choice anotherChoice)
{
    // write your code after this line
    IO.output("Please input your choice (0=rock, 1=paper, 2=scissors)");
    type = IO.inputInteger( );
    anotherChoice = new Choice(0);        
    int gameResult = type.compareWith(anotherChoice);
    switch(gameResult)
    {
        case -1: IO.outputln("You Win!"); break;
        case 0: IO.outputln("Draw!"); break;
        case 1: IO.outputln("You Lose!"); break;
    }

    return gameResult; // this line should be modified/removed upon finishing the implementation of this method
}

请帮助!!