Android封装一个通用的失败重试工具类

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Android使用rxjava封装重试处理工具类 - 简书

我们在做一些异步请求时，为了确保请求成功需要进行重试。
那么我们需要灵活的配置重试间隔时间，重试次数， 还需要写个倒计时代码。
为此，本文使用rxjava为基础封装了一个工具类。
其中要注意的是内存泄漏问题，为此使用rxjava的周期组件AndroidLifecycleScopeProvider进行处理，如果非全局上下文需要在构造方法传入LifecycleOwner类。
下面直接上代码：

public class RetryForTimeDownHelper {
    private static final String TAG = "RetryForTimeDownHelper";

    /**
     * 重试次数
     */
    private volatile int retryCount;

    /**
     * 最大重试次数
     */
    private int maxRetryCount;

    /**
     * 重试时间
     */
    private long retryTimeMilli;
    private OnRetryCallBack onRetryCallBack;
    private WeakReference<LifecycleOwner> lifecycleOwnerWeakReference;

    /**
     * @param lifecycleOwner  非全局上下文需要传入，防止内存泄漏
     * @param maxRetryCount   最多重试次数
     * @param retryTimeMilli  重试间隔时间  单位毫秒
     * @param onRetryCallBack 重试回调：重试、重试结束处理结果
     */
    public RetryForTimeDownHelper(LifecycleOwner lifecycleOwner, int maxRetryCount, long retryTimeMilli, OnRetryCallBack onRetryCallBack) {
        if (lifecycleOwner != null) {
            this.lifecycleOwnerWeakReference = new WeakReference<>(lifecycleOwner);
        }
        this.maxRetryCount = maxRetryCount;
        this.retryTimeMilli = retryTimeMilli;
        this.onRetryCallBack = onRetryCallBack;
    }

    public RetryForTimeDownHelper(int maxRetryCount, long retryTimeMilli, OnRetryCallBack onRetryCallBack) {
        this(null, maxRetryCount, retryTimeMilli, onRetryCallBack);
    }

    public int getRetryCount() {
        return retryCount;
    }

    public void retry(FailBean failBean) {
        retryCount++;
        if (retryCount > maxRetryCount) {
            if (onRetryCallBack != null) {
                onRetryCallBack.onComplete(failBean);
            }
            return;
        }
        //非全局上下文需要传入，防止内存泄漏
        if (lifecycleOwnerWeakReference != null) {
            LifecycleOwner lifecycleOwner = lifecycleOwnerWeakReference.get();
            if (lifecycleOwner != null) {
                timeDownRetryLifecycle(lifecycleOwner);
            }
            return;
        }
        //全局上下文中
        timeDownRetry();
    }

    private void timeDownRetry() {
        //倒计时3秒 重试
        Observable.timer(retryTimeMilli, TimeUnit.MILLISECONDS)
                .subscribe(new Observer<Long>() {
                    @Override
                    public void onSubscribe(@NonNull Disposable disposable) {
                    }

                    @Override
                    public void onNext(@NonNull Long number) {
                        if (onRetryCallBack != null) {
                            onRetryCallBack.onNext();
                        }
                    }

                    @Override
                    public void onError(@NonNull Throwable throwable) {
                        if (throwable != null) {
                           Log.e(TAG, "onError: ", throwable);
                        }
                    }

                    @Override
                    public void onComplete() {
                    }
                });
    }

    private void timeDownRetryLifecycle(LifecycleOwner lifecycleOwner) {
        //倒计时3秒 重试
        Observable.timer(retryTimeMilli, TimeUnit.MILLISECONDS)
                //AutoDispose 防止内存泄漏
                .as(AutoDispose.<Long>autoDisposable(AndroidLifecycleScopeProvider.from(lifecycleOwner)))
                .subscribe(new Observer<Long>() {
                    @Override
                    public void onSubscribe(@NonNull Disposable disposable) {
                    }

                    @Override
                    public void onNext(@NonNull Long number) {
                        if (onRetryCallBack != null) {
                            onRetryCallBack.onNext();
                        }
                    }

                    @Override
                    public void onError(@NonNull Throwable throwable) {
                        if (throwable != null) {
                             Log.e(TAG, "onError: ", throwable);
                        }
                    }

                    @Override
                    public void onComplete() {
                    }
                });
    }

    public interface OnRetryCallBack {
        /**
         * 调用重试
         */
        void onNext();

        /**
         * 处理结果
         */
        void onComplete(FailBean failBean);
    }

    public static class FailBean {
        private String errorCodeStr;
        private String errorMsgStr;

        public String getErrorCodeStr() {
            return errorCodeStr;
        }

        public void setErrorCodeStr(String errorCodeStr) {
            this.errorCodeStr = errorCodeStr;
        }

        public String getErrorMsgStr() {
            return errorMsgStr;
        }

        public void setErrorMsgStr(String errorMsgStr) {
            this.errorMsgStr = errorMsgStr;
        }
    }
}

使用步骤

我们以登录为例

1、在调用登录时构造对象

private volatile RetryForTimeDownHelper retryForTimeDownHelper;
public void login(){
//重试3次，间隔3秒重试
retryForTimeDownHelper = new RetryForTimeDownHelper(3, 3 * 1000, new RetryForTimeDownHelper.OnRetryCallBack() {
                @Override
                public void onNext() {
                    //重试登录
                    reLogin();
                }

                @Override
                public void onComplete() {
                    //处理登录失败结果
                    setFail();
                }
            });
   //登录的实现方法
   reLogin();
}

其中回调方法onNext()是进行重试的方法，onComplete()处理重试失败结果

2、在登录失败时调用下重试

    public void reLogin() {
        LoginHelper.getInstance().login(userId, token, new LoginCallBack(){
            @Override
            public void onFailed (String errorCode){
                if (retryForTimeDownHelper != null) {
                    RetryForTimeDownHelper.FailBean failBean = new RetryForTimeDownHelper.FailBean();
                    failBean.setErrorCodeStr(errorCode);
                    retryForTimeDownHelper.retry(failBean);
                }
            }
            @Override
            public void onSuccess () {
                retryForTimeDownHelper = null;
            }
        }
    }