无法在 Android WebView 中设置 HttpURLConnection headers

Question

我试图拦截 WebView 发送的每个请求并在执行请求之前修改 headers。有很多关于如何执行此操作的示例（Chrome 调试器中的 like this one), but I can't quite get it to work. Pages are able to load fine, but all of the requests look something like this；他们警告说我的 headers 的 "Provisional headers are shown" 和 none 存在。

这是我的代码的相关部分：

public class MyWebView extends WebView {

    public MyWebView(Context context) {
        super(context);
        setWebViewClient(new MyWebViewClient());
    }

    private class MyWebViewClient extends WebViewClient {

        @Override
        public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
            WebResourceResponse response = null;
            try {
                URL url = new URL(request.getUrl().toString());
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setRequestMethod(request.getMethod());
                conn.setRequestProperty("test-header", "test-value");

                InputStream data;
                if (conn.getResponseCode() / 100 == 2) {
                    data = conn.getInputStream();
                }
                else {
                    data = conn.getErrorStream();
                }

                response = new WebResourceResponse("text/html", "UTF-8", data);
            }
            catch (IOException e) {

            }

            return response;
        }
    }
}

我也尝试过使用 OkHttp，但得到了相同的结果。有人能让这个工作吗？

Answer 1

试试这个，而不是 shouldOverrideUrlLoading 而不是 shouldInterceptRequest

public class MyWebView extends WebView {

    public MyWebView(Context context) {
        super(context);
        setWebViewClient(new MyWebViewClient());
    }

    private class MyWebViewClient extends WebViewClient {
        @Override
        @TargetApi(Build.VERSION_CODES.LOLLIPOP)
        public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request)
        {
            final String url = request.getUrl().toString();
            return getNewResponse(url);
        }

        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url)
        {
            return getNewResponse(url);
        }

        private WebResourceResponse getNewResponse(String url) {
            final OkHttpClient httpClient = new OkHttpClient();
            Response response = null;
            try {
                final Request request = new Request.Builder()
                        .url(url.trim())
                        .addHeader("test-header", "test-value")
                        .build();
                response = httpClient.newCall(request).execute();
            }
            catch (Exception e) {
            }
            if (response == null) {
                return null;
            }
            return new WebResourceResponse(
                    getMimeType(url),
                    response.header("content-encoding", "utf-8"),
                    response.body().byteStream()
            );
        }

        private String getMimeType(String url) {
            final String extension = MimeTypeMap.getFileExtensionFromUrl(url);

            if (extension == null) {
                return null;
            }
            switch (extension) {
                case "js":
                    return "text/javascript";
                case "woff":
                    return "application/font-woff";
                case "woff2":
                    return "application/font-woff2";
                case "ttf":
                    return "application/x-font-ttf";
                case "eot":
                    return "application/vnd.ms-fontobject";
                case "svg":
                    return "image/svg+xml";
                case "mp4":
                    return "video/mp4";
            }

            return MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
        }
    }
}

Answer 2

事实证明，我的代码实际上运行良好。问题似乎是 Chrome 网络检查器无法访问通过 HttpURLConnection（或 WebView 本身以外的任何内容）发送的请求的请求元数据，所以我的 headers 只是没有出现在那里。但是，使用 this tool 我迅速将所有请求 headers 显示为 json，我可以看到它们实际上是按预期交付的。

无法在 Android WebView 中设置 HttpURLConnection headers

Unable to set HttpURLConnection headers in Android WebView

java

android

httpurlconnection