Wie beurteilt man 404 in der Webansicht unter Android?

Question

Ich verwende

 @Override
        public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
            super.onReceivedError(view, request, error);
            PtrCLog.d("WebFragment", "onReceivedError: " + "");

        }
        
        

Diese Methode wurde nicht zurückgesetzt. Ich habe nachgesehen und festgestellt, dass sie API23 erfordert. . Kennt jemand andere Möglichkeiten, an 404 zu kommen?

Answer 1

        new WebViewClient() {
            @Override
            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                super.onReceivedError(view, errorCode, description, failingUrl);
                if (errorCode == 404) {
                    doSomething();
                }
            }

            @Override
            public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
                super.onReceivedError(view, request, error);
                if (Build.VERSION.SDK_INT > Build.VERSION_CODES.M) {
                    int errorCode = error.getErrorCode();
                    if (errorCode == 404) {
                        doSomething();
                    }
                }
            }
        };

Answer 2

在onPageStarted里边跑一个AsyncTask，在AsyncTask里用OkHttpClient之类的Http客户端对需要访问的URL进行一次请求，取得code

    class WebViewStatusRequester extends AsyncTask<String, String, Integer> {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            web.setVisibility(View.GONE);
        }
        @Override
        protected void onPostExecute(Integer result) {
            super.onPostExecute(result);
            if(result == 1) {
                web.setVisibility(View.VISIBLE);
            } else if(result == 0) {
                showLoadFail();
            }
        }
        @Override
        protected Integer doInBackground(String... params) {
            String url = params[0];
            if(url.substring(0, 4).equals("file") == false) {
                try {
                    OkHttpClient client = new OkHttpClient();
                    Request request = new Request.Builder().url(url).build();
                    Response response = client.newCall(request).execute();
                    if(response.isSuccessful()) {
                        return 1;
                    } else {
                        Log.i("TAG", "fail code:" + response.code());
                        return 0;
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
                return 0;
            }
            return 1;
        }
    }

在这里实际上是Webview和OkHttpClient进行了加载，只是AsyncTask跑的时候把WebView隐藏起来了，确认是200了就显示，不是200就显示加载失败的页面