mWebView.setWebViewClient(new CommentWebViewClient());
    
public class CommentWebViewClient extends WebViewClient {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        return openApp(url);
    }
}

//判断app是否安装
private boolean isInstall(Intent intent) {
    return MLApplication.getInstance().getPackageManager().queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY).size() > 0;
}

//打开app
private boolean openApp(String url) {
    if (TextUtils.isEmpty(url)) return false;
    try {
        if (!url.startsWith("http") && !url.startsWith("https") && !url.startsWith("ftp")) {
        	Uri uri = Uri.parse(url);
            String host = uri.getHost();
            String scheme = uri.getScheme();
            //host 和 scheme 都不能为null
             if (!TextUtils.isEmpty(host) && !TextUtils.isEmpty(scheme)) {
                Intent intent = new Intent(Intent.ACTION_VIEW, uri);
                if (isInstall(intent)) {
                    startActivity(intent);
                    return true;
                }
            }
        }
    } catch (Exception e) {
        return false;
    }
    return false;
}