@Entity

@Table(name = "game")

public class Game {

    @Id

    @GeneratedValue

    private Integer gid;

    private String gname;

    @ManyToMany(mappedBy = "games",cascade = CascadeType.ALL)

    private Set<Player> players=new HashSet<Player>();

    public Integer getGid() {

        return gid;

    }

    public void setGid(Integer gid) {

        this.gid = gid;

    }

    public String getGname() {

        return gname;

    }

    public void setGname(String gname) {

        this.gname = gname;

    }

    public Set<Player> getPlayers() {

        return players;

    }

    public void setPlayers(Set<Player> players) {

        this.players = players;

    }

}

@Entity

@Table(name = "player")

public class Player {

    @Id

    @GeneratedValue

    private Integer pid;

    private String pname;

    @ManyToMany(cascade = CascadeType.ALL)

    @JoinTable(name = "pg",joinColumns = @JoinColumn(name = "pid"),inverseJoinColumns = @JoinColumn(name = "gid"))

    private Set<Game> games=new HashSet<Game>();

    public Integer getPid() {

        return pid;

    }

    public void setPid(Integer pid) {

        this.pid = pid;

    }

    public String getPname() {

        return pname;

    }

    public void setPname(String pname) {

        this.pname = pname;

    }

    public Set<Game> getGames() {

        return games;

    }

    public void setGames(Set<Game> games) {

        this.games = games;

    }

}

<mapping class="cn.wyd.a.Game"/>

		<mapping class="cn.wyd.a.Player"/>

 @Test

    public void test1() {

        Game game1 = new Game();

        Game game2 = new Game();

        game1.setGname("g1");

        game2.setGname("g2");

        Player player = new Player();

        player.setPname("123");

        player.getGames().add(game1);

        player.getGames().add(game2);

        game1.getPlayers().add(player);

        game2.getPlayers().add(player);

        session.save(player);

    }