[java] WebView 리소스 요청에 사용자 지정 헤더 추가-Android

다음은 HttpUrlConnection을 사용한 구현입니다.

class CustomWebviewClient : WebViewClient() {
    private val charsetPattern = Pattern.compile(".*?charset=(.*?)(;.*)?$")

    override fun shouldInterceptRequest(view: WebView, request: WebResourceRequest): WebResourceResponse? {
        try {
            val connection: HttpURLConnection = URL(request.url.toString()).openConnection() as HttpURLConnection
            connection.requestMethod = request.method
            for ((key, value) in request.requestHeaders) {
                connection.addRequestProperty(key, value)
            }

            connection.addRequestProperty("custom header key", "custom header value")

            var contentType: String? = connection.contentType
            var charset: String? = null
            if (contentType != null) {
                // some content types may include charset => strip; e. g. "application/json; charset=utf-8"
                val contentTypeTokenizer = StringTokenizer(contentType, ";")
                val tokenizedContentType = contentTypeTokenizer.nextToken()

                var capturedCharset: String? = connection.contentEncoding
                if (capturedCharset == null) {
                    val charsetMatcher = charsetPattern.matcher(contentType)
                    if (charsetMatcher.find() && charsetMatcher.groupCount() > 0) {
                        capturedCharset = charsetMatcher.group(1)
                    }
                }
                if (capturedCharset != null && !capturedCharset.isEmpty()) {
                    charset = capturedCharset
                }

                contentType = tokenizedContentType
            }

            val status = connection.responseCode
            var inputStream = if (status == HttpURLConnection.HTTP_OK) {
                connection.inputStream
            } else {
                // error stream can sometimes be null even if status is different from HTTP_OK
                // (e. g. in case of 404)
                connection.errorStream ?: connection.inputStream
            }
            val headers = connection.headerFields
            val contentEncodings = headers.get("Content-Encoding")
            if (contentEncodings != null) {
                for (header in contentEncodings) {
                    if (header.equals("gzip", true)) {
                        inputStream = GZIPInputStream(inputStream)
                        break
                    }
                }
            }
            return WebResourceResponse(contentType, charset, status, connection.responseMessage, convertConnectionResponseToSingleValueMap(connection.headerFields), inputStream)
        } catch (e: Exception) {
            e.printStackTrace()
        }
        return super.shouldInterceptRequest(view, request)
    }

    private fun convertConnectionResponseToSingleValueMap(headerFields: Map<String, List<String>>): Map<String, String> {
        val headers = HashMap<String, String>()
        for ((key, value) in headerFields) {
            when {
                value.size == 1 -> headers[key] = value[0]
                value.isEmpty() -> headers[key] = ""
                else -> {
                    val builder = StringBuilder(value[0])
                    val separator = "; "
                    for (i in 1 until value.size) {
                        builder.append(separator)
                        builder.append(value[i])
                    }
                    headers[key] = builder.toString()
                }
            }
        }
        return headers
    }
}

WebResourceRequest는 POST 데이터를 제공하지 않기 때문에 POST 요청에는 작동하지 않습니다. POST 데이터를 가로 채기 위해 JavaScript 주입 해결 방법을 사용 하는 Request Data-WebViewClient 라이브러리 가 있습니다.