在Android中拦截WebView请求的最佳方法 [英] The best way to intercept a WebView request in Android

问题描述

我在我的应用中使用 WebView ，我必须拦截请求。我目前正在使用以下代码来执行此操作。

I am using a WebView in my app in which I must intercept requests. I am currently using the follwing code to do it.

public WebResourceResponse shouldInterceptRequest (WebView view, String url) {
    HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
    conn.setRequestProperty("User-Agent", userAgent);

    String mime;
    if (url.lastIndexOf('.') > url.lastIndexOf('/')) {
        String ext = url.substring(url.lastIndexOf('.') + 1);
        mime = MimeTypeMap.getSingleton().getMimeTypeFromExtension(ext);
    } else {
       mime = "text/html";
    }
    return new WebResourceResponse(mime, "UTF-8", conn.getInputStream());
}

以上代码在大多数情况下都能正常工作，但并非全部。例如，当我尝试登录Outlook时，它只是显示我的电子邮件或密码不正确，我还看到其他请求被破坏的情况，但如果我删除 shouldInterceptRequest 。

Above code works fine in most cases, but no all. For example when I try to login to Outlook, it just shows that my email or password is incorrect, I have also seen other cases in which requests get broken, but everything works fine if I remove shouldInterceptRequest.

我目前用来拦截请求的方法有哪些更好的方式？

Is there any better way that the one I am currently using to intercept requests?

推荐答案

您的代码存在两个问题

1. 扩展检测不正确

例如，当代码尝试获取此URL的资源扩展时：

For example, when the code try to get resource extension for this URL:

https://login.live.com/login.srf?wa=wsignin1.0&rpsnv=12&ct=1442476202&rver=6.4.6456.0&wp=MBI_SSL_SHARED&wreply=https:%2F%2Fmail.live.com%2Fdefault.aspx%3Frru%3Dinbox&lc=1033&id=64855&mkt=en-us&cbcxt=mai

它将返回 aspx％3Frru％3Dinbox& lc = 1033& id = 64855& mkt = en-us& cbcxt = mai 这是错的。有一种从URL获取扩展的特殊方法： getFileExtensionFromUrl（）

It will return aspx%3Frru%3Dinbox&lc=1033&id=64855&mkt=en-us&cbcxt=mai which is wrong. There is special method for getting extension from the URL: getFileExtensionFromUrl()

1. 根据文档方法 MimeTypeMap.getSingleton（）。getMimeTypeFromExtension（EXT） 可能会返回 null 。在这种情况下，您的代码为页面设置了错误的mime类型。

1. According to documentation method MimeTypeMap.getSingleton().getMimeTypeFromExtension(ext) may return null. In this case your code set wrong mime type for the page.

以下是考虑这两个问题的方法代码

Here is the method code that take into account both these issues

@Override
public WebResourceResponse shouldInterceptRequest(WebView view,
    String url) {
    String ext = MimeTypeMap.getFileExtensionFromUrl(url);
    String mime = MimeTypeMap.getSingleton().getMimeTypeFromExtension(ext);
    if (mime == null) {
        return super.shouldInterceptRequest(view, url);
    } else {
        HttpURLConnection conn = (HttpURLConnection) new URL(
                                                 url).openConnection();
        conn.setRequestProperty("User-Agent", userAgent);
        return new WebResourceResponse(mime, "UTF-8",
                                                 conn.getInputStream());
    }
}

这篇关于在Android中拦截WebView请求的最佳方法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！