CODEWITHSUNDEEP
lambdajava-8java-streamcollectors
sadat.anv
sadat.anv

Reputation: 33

java 8 lambda toMap showing type cast error

I am getting type cast error when trying to collect the list of objects to Map using lambda expression java 8

here is the code:

public static void main(String[] args){
List<Player> players = Arrays.asList(
        new Player("Liz", Gender.FEMALE, 20),
        new Player("Liz", Gender.FEMALE, 22),
        new Player("Bob", Gender.MALE, 20)          
        );

System.out.println(
        players.stream()
                 .collect(toMap(
                         player -> player.getName()+"_"+player.getAge(), 
// above line giving error. 
//The method getAge() is undefined for the type Object
//- The method getName() is undefined for the type Object                                
                         player -> player))
        );

}

once I type cast it to (Player) like below, it works fine. any idea why compiler asking for type cast?

player -> ((Player) player).getName()+"_"+((Player) player).getAge()

Player class is as below:

class Player {

private String name;
private Integer age;
private Gender gender;

public Player(String name, Gender gender, Integer age){
    this.name = name;
    this.gender = gender;
    this.age = age;
}
// ...... with corresponding getters and setters    
}

Upvotes: 3

Views: 1073

Answers (1)

Joe C
Joe C

Reputation: 15714

This has been an issue in certain versions (I want to say 1.8.0_45, but I can't confirm). I just tried your code on 1.8.0_71 and it works for me.

The latest version is 1.8.0_111, so you should try upgrading to that.

Upvotes: 2

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