我經曆的一些java 編程tips

1  private的網域設定成final，只能通過建構函式初始化，不提供setter。這些屬性是一個對象必須的屬性，並且不可修改。

public class Transition{    private final String name;    private final Guard  guard;    private final State  input;    private final Action action;    private final State  output;    /**     * Creates a new transition instance.     *      * @param name Transition name     * @param input Input state     * @param guard Condition guarding the transition     * @param action An action to take when the transition is triggered     * @param output Output state     */    public Transition(String name, Guard guard, State input, Action action,            State output)    {        this.name = name;        this.guard = guard;        this.input = input;        this.action = action;        this.output = output;    }}