注解的简单用例

1,定义注解类

import android.support.annotation.StringDef;

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

@StringDef({SmsType.BIND, SmsType.GENERAL, SmsType.REG, SmsType.EDITPWD, SmsType.LOGIN})
@Retention(RetentionPolicy.SOURCE)
public @interface SmsType {
    String BIND = "bind";
    String GENERAL = "general";
    String REG = "reg";
    String EDITPWD = "editpwd";
    String LOGIN = "login";
}

2，在形参中添加注解约束@SmsType String type

import android.content.Context;

import com.jiyou.sdklibrary.base.BasePresenter;
import com.jiyou.sdklibrary.mvp.cons.SmsType;
import com.jiyou.sdklibrary.mvp.view.VerificationCodeView;

public interface VerificationCodePresenter extends BasePresenter<VerificationCodeView> {
    void getCode(String phone, @SmsType String type, Context context);
}

3，在实现中，形参不需要添加注解约束@SmsType String type

@Override
    public void getCode(String phone, String type, Context context) {
        boolean phoneTag = phone.length() == 11;
        if ((TextUtils.isEmpty(phone))) {
            verificationCodeView.showAppInfo("", "手机号输入为空");
            return;
        } else {
            if (phoneTag) {
                getSmsCodeMethod(context, HttpUrlConstants.URL_SDK_SMSCODE, phone, type);
            } else {
                verificationCodeView.showAppInfo("", "手机号长度格式错误");
                return;
            }
        }
    }

4,在调用改方法时，参数被约束了，成功。

verificationCodePresenterImp.getCode(mPhone, SmsType.BIND, JYSdkBindActivity.this);

具体分析可看Android 注解约束参数