WebView加载url，读取本地文件

 webView.loadUrl(url);

  webView.setWebChromeClient(new WebChromeClient() {
            @Override
            @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
            public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
                return super.onShowFileChooser(webView, filePathCallback, fileChooserParams);
                if (uploadMessage != null) {
                    uploadMessage.onReceiveValue(null);
                    uploadMessage = null;
                }

                uploadMessage = filePathCallback;
                Intent intent = fileChooserParams.createIntent();
                try {
                    startActivityForResult(intent, REQUEST_FILE_CODE);
                } catch (ActivityNotFoundException e) {
                    uploadMessage = null;
                    Toast.makeText(WebViewAct.this, "Cannot open file               chooser", Toast.LENGTH_LONG).show();
                    return false;
                }
                return true;
            }
        });

    public ValueCallback<Uri[]> uploadMessage;
    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_FILE_CODE) {
            if (uploadMessage == null) return;
            uploadMessage.onReceiveValue(WebChromeClient.FileChooserParams.parseResult(resultCode, data));
            uploadMessage = null;
        }
    }