Android @IntDef注解取代Java enum枚举提高性能

Android @IntDef注解取代Java enum枚举提高性能

为提高Android性能，Android官方建议使用@IntDef注解替代Java的enum枚举。@IntDef的使用给出一个例子，先建立@IntDef数据结构模型，例如MyDay.java：

package zhangphil.test;

import android.support.annotation.IntDef;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

public class MyDay {
    public static final int SUNDAY = 0;
    public static final int MONDAY = 1;
    public static final int TUESDAY = 2;
    public static final int WEDNESDAY = 3;
    public static final int THURSDAY = 4;
    public static final int FRIDAY = 5;
    public static final int SATURDAY = 6;

    @IntDef({SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY})
    @Retention(RetentionPolicy.SOURCE)
    public @interface WeekDays {

    }

    @WeekDays
    private int mCurDay = SUNDAY;

    public void setCurrentDay(@WeekDays int currentDay) {
        this.mCurDay = currentDay;
    }

    @WeekDays
    public int getCurrentDay() {
        return mCurDay;
    }
}

使用：

        MyDay days = new MyDay();

        days.setCurrentDay(MyDay.TUESDAY);

        @MyDay.WeekDays int day = days.getCurrentDay();

        switch (day) {
            case MyDay.SUNDAY:
                break;

            case MyDay.MONDAY:
                break;

            case MyDay.TUESDAY:
                break;

            case MyDay.WEDNESDAY:
                break;

            case MyDay.THURSDAY:
                break;

            case MyDay.FRIDAY:
                break;

            case MyDay.SATURDAY:
                break;

            default:
                break;
        }