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How to redirect s3 link from rest controller java

we have S3 storage ,there are a lot of some files, jpg,mp3 and others
what i need to do?
i need to redirect client to get the file from our s3 without uploading it on our server
and i want that clien get the file on his pc with name and extension
so it looks like clien send us uuid - we find link of this file on s3 and redirect it like this
#GetMapping("/test/{uuid}")
public ResponseEntity<Void> getFile(#PathVariable UUID uuid) {
var url = storageServiceS3.getUrl(uuid);
try {
var name = storageServiceS3.getName(uuid);
return ResponseEntity.status(HttpStatus.MOVED_PERMANENTLY)
.header(HttpHeaders.LOCATION, url)
.header(HttpHeaders.CONTENT_TYPE, new MimetypesFileTypeMap().getContentType(name))
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=" + name)
.build();
} catch (NoSuchKeyException ex) {
return ResponseEntity.status(HttpStatus.NOT_FOUND)
.build();
}
}
everything works good ,the file is downloading but one problem - the file has no name (its name still is key from s3) and no extension.
i think this code not works correctly
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=" + name)
is there any way to do this or i still need upload file to server and then send it to client ?

Finally i found solution- i use S3Presigner ,make presigned url and redirect it with simple Http response
#Bean
public S3Presigner getS3Presigner() {
return S3Presigner.builder()
.credentialsProvider(StaticCredentialsProvider.create(AwsBasicCredentials.create(ACCESS_KEY, SECRET_KEY)))
.region(Region.of(REGION))
.endpointOverride(URI.create(END_POINT))
.build();
}
public String getPresignedURL(UUID uuid) {
var name = getName(uuid);
var contentDisposition = "attachment;filename=" + name;
var contentType = new MimetypesFileTypeMap().getContentType(name);
GetObjectRequest getObjectRequest = GetObjectRequest.builder()
.bucket(BUCKET)
.key(uuid.toString())
.responseContentDisposition(contentDisposition)
.responseContentType(contentType)
.build();
GetObjectPresignRequest getObjectPresignRequest =
GetObjectPresignRequest.builder()
.signatureDuration(Duration.ofMinutes(5))
.getObjectRequest(getObjectRequest)
.build();
PresignedGetObjectRequest presignedGetObjectRequest =
s3Presigner.presignGetObject(getObjectPresignRequest);
return presignedGetObjectRequest.url().toString();
}
#GetMapping("/redirect/{uuid}")
public void redirectToS3(#PathVariable UUID uuid, HttpServletResponse response) {
try {
var URI = storageServiceS3.getPresignedURL(uuid);
response.sendRedirect(URI);
} catch (NoSuchKeyException | IOException e) {
response.setStatus(404);
}
}
It works pretty good ;)

#Алексеев станислав
Some work arround for this is consuming your rest service by javascript and add file's name in a new header response and rename file when download by client.
// don't forget to allow X-File-Name header on CORS in spring
headers.add("X-File-Name", nameToBeDownloaded );
Example on ANGULAR but can be parsed to other language
this.http.get(uri_link_spring_redirecting_to_S3, {
responseType: 'blob',
observe: 'response'
}).subscribe(
(response) => {
var link = document.createElement('a');
var file = new Blob([response.body], {
type: 'text/csv;charset=utf-8;'
});
link.href = window.URL.createObjectURL(file);
link.download = response?.headers?.get('X-File-Name');; 'download.csv';
link.click();
},
error => {
...
}
)

How to change base URL using retrofit2 and koin 2.0

I have a query that returns a list of servers, and the user can select the server he needs.
Googling did not help, almost no results.
Tell me how to implement basic URL spoofing in real time using Koin and Retrofit?
My Modules:
fun createMainModule(context: Context) = module {
single(named(APP_CONTEXT)) { context }
single(named(RESOURCES)) { context.resources }
single(named(REPOSITORY)) {
Repository(get(named(RETROFIT)))
}
}
fun createNetworkModule(baseUrl: String) = module(override = true) {
single(named(TOKEN_INTERCEPTOR)) { createTokenInterceptor(get(named(DATA_PROVIDER))) }
single(named(OK_HTTP)) { createOkHttpClient(get(named(TOKEN_INTERCEPTOR))) }
single(named(GSON)) { createGson() }
single(named(RETROFIT)) {
createRetrofit(
get(named(RESOURCES)),
get(named(LOG_OUT_SUBJECT)),
get(named(GSON)),
baseUrl,
get(named(OK_HTTP))
)
}

I resolve my problem with comment #sonnet
This code:
class ChangeableBaseUrlInterceptor : Interceptor {
#Volatile
private var host: HttpUrl? = null
fun setHost(host: String) {
this.host = host.toHttpUrlOrNull()
}
fun clear() {
host = null
}
#Throws(IOException::class)
override fun intercept(chain: Interceptor.Chain): okhttp3.Response {
var request = chain.request()
host?.let {
val newUrl = request.url.newBuilder()
.scheme(it.scheme)
.host(it.toUrl().toURI().host)
.port(it.port)
.build()
request = request.newBuilder().url(newUrl).build()
}
return chain.proceed(request)
}
}

Adding header to all request with Retrofit 2

Retrofit 2's documentation says:
Headers that need to be added to every request can be specified using an OkHttp interceptor.
It can be done easily using the previous version, here's the related QA.
But using retrofit 2, I couldn't find something like setRequestInterceptor or setInterceptor method that can be applied to Retrofit.Builder object.
Also it seems that there's no RequestInterceptor in OkHttp anymore. Retrofit's doc refers us to Interceptor that I didn't quite understand how to use it for this purpose.
How can I do this?

OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
httpClient.addInterceptor(new Interceptor() {
#Override
public Response intercept(Chain chain) throws IOException {
Request request = chain.request().newBuilder().addHeader("parameter", "value").build();
return chain.proceed(request);
}
});
Retrofit retrofit = new Retrofit.Builder().addConverterFactory(GsonConverterFactory.create()).baseUrl(url).client(httpClient.build()).build();

The Latest Retrofit Version HERE -> 2.1.0.
lambda version:
builder.addInterceptor(chain -> {
Request request = chain.request().newBuilder().addHeader("key", "value").build();
return chain.proceed(request);
});
ugly long version:
builder.addInterceptor(new Interceptor() {
#Override public Response intercept(Chain chain) throws IOException {
Request request = chain.request().newBuilder().addHeader("key", "value").build();
return chain.proceed(request);
}
});
full version:
class Factory {
public static APIService create(Context context) {
OkHttpClient.Builder builder = new OkHttpClient().newBuilder();
builder.readTimeout(10, TimeUnit.SECONDS);
builder.connectTimeout(5, TimeUnit.SECONDS);
if (BuildConfig.DEBUG) {
HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BASIC);
builder.addInterceptor(interceptor);
}
builder.addInterceptor(chain -> {
Request request = chain.request().newBuilder().addHeader("key", "value").build();
return chain.proceed(request);
});
builder.addInterceptor(new UnauthorisedInterceptor(context));
OkHttpClient client = builder.build();
Retrofit retrofit =
new Retrofit.Builder().baseUrl(APIService.ENDPOINT).client(client).addConverterFactory(GsonConverterFactory.create()).addCallAdapterFactory(RxJavaCallAdapterFactory.create()).build();
return retrofit.create(APIService.class);
}
}
gradle file (you need to add the logging interceptor if you plan to use it):
//----- Retrofit
compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile "com.squareup.retrofit2:converter-gson:2.1.0"
compile "com.squareup.retrofit2:adapter-rxjava:2.1.0"
compile 'com.squareup.okhttp3:logging-interceptor:3.4.0'

Try this type header for Retrofit 1.9 and 2.0. For Json Content Type.
#Headers({"Accept: application/json"})
#POST("user/classes")
Call<playlist> addToPlaylist(#Body PlaylistParm parm);
You can add many more headers i.e
#Headers({
"Accept: application/json",
"User-Agent: Your-App-Name",
"Cache-Control: max-age=640000"
})
Dynamically Add to headers:
#POST("user/classes")
Call<ResponseModel> addToPlaylist(#Header("Content-Type") String content_type, #Body RequestModel req);
Call you method i.e
mAPI.addToPlayList("application/json", playListParam);
Or
Want to pass everytime then Create HttpClient object with http Interceptor:
OkHttpClient httpClient = new OkHttpClient();
httpClient.networkInterceptors().add(new Interceptor() {
#Override
public com.squareup.okhttp.Response intercept(Chain chain) throws IOException {
Request.Builder requestBuilder = chain.request().newBuilder();
requestBuilder.header("Content-Type", "application/json");
return chain.proceed(requestBuilder.build());
}
});
Then add to retrofit object
Retrofit retrofit = new Retrofit.Builder().baseUrl(BASE_URL).client(httpClient).build();
UPDATE if you are using Kotlin remove the { } else it will not work

For Logging your request and response you need an interceptor and also for setting the header you need an interceptor, Here's the solution for adding both the interceptor at once using retrofit 2.1
public OkHttpClient getHeader(final String authorizationValue ) {
HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient okClient = new OkHttpClient.Builder()
.addInterceptor(interceptor)
.addNetworkInterceptor(
new Interceptor() {
#Override
public Response intercept(Interceptor.Chain chain) throws IOException {
Request request = null;
if (authorizationValue != null) {
Log.d("--Authorization-- ", authorizationValue);
Request original = chain.request();
// Request customization: add request headers
Request.Builder requestBuilder = original.newBuilder()
.addHeader("Authorization", authorizationValue);
request = requestBuilder.build();
}
return chain.proceed(request);
}
})
.build();
return okClient;
}
Now in your retrofit object add this header in the client
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(url)
.client(getHeader(authorizationValue))
.addConverterFactory(GsonConverterFactory.create())
.build();

In my case addInterceptor()didn't work to add HTTP headers to my request, I had to use addNetworkInterceptor(). Code is as follows:
OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
httpClient.addNetworkInterceptor(new AddHeaderInterceptor());
And the interceptor code:
public class AddHeaderInterceptor implements Interceptor {
#Override
public Response intercept(Chain chain) throws IOException {
Request.Builder builder = chain.request().newBuilder();
builder.addHeader("Authorization", "MyauthHeaderContent");
return chain.proceed(builder.build());
}
}
This and more examples on this gist

If you use addInterceptor method for add HttpLoggingInterceptor, it won't be logging the things that added by other interceptors applied later than HttpLoggingInterceptor.
For example: If you have two interceptors "HttpLoggingInterceptor" and "AuthInterceptor", and HttpLoggingInterceptor applied first, then you
can't view the http-params or headers which set by AuthInterceptor.
OkHttpClient.Builder builder = new OkHttpClient.Builder()
.addNetworkInterceptor(logging)
.addInterceptor(new AuthInterceptor());
I solved it, via using addNetworkInterceptor method.

In kotlin adding interceptor looks that way:
.addInterceptor{ it.proceed(it.request().newBuilder().addHeader("Cache-Control", "no-store").build())}

Use this Retrofit Client
class RetrofitClient2(context: Context) : OkHttpClient() {
private var mContext:Context = context
private var retrofit: Retrofit? = null
val client: Retrofit?
get() {
val logging = HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.BODY)
val client = OkHttpClient.Builder()
.connectTimeout(Constants.TIME_OUT, TimeUnit.SECONDS)
.readTimeout(Constants.TIME_OUT, TimeUnit.SECONDS)
.writeTimeout(Constants.TIME_OUT, TimeUnit.SECONDS)
client.addInterceptor(logging)
client.interceptors().add(AddCookiesInterceptor(mContext))
val gson = GsonBuilder().setDateFormat("yyyy-MM-dd'T'HH:mm:ssZ").create()
if (retrofit == null) {
retrofit = Retrofit.Builder()
.baseUrl(Constants.URL)
.addConverterFactory(GsonConverterFactory.create(gson))
.client(client.build())
.build()
}
return retrofit
}
}
I'm passing the JWT along with every request. Please don't mind the variable names, it's a bit confusing.
class AddCookiesInterceptor(context: Context) : Interceptor {
val mContext: Context = context
#Throws(IOException::class)
override fun intercept(chain: Interceptor.Chain): Response {
val builder = chain.request().newBuilder()
val preferences = CookieStore().getCookies(mContext)
if (preferences != null) {
for (cookie in preferences!!) {
builder.addHeader("Authorization", cookie)
}
}
return chain.proceed(builder.build())
}
}

RetrofitHelper library written in kotlin, will let you make API calls, using a few lines of code.
Add headers in your application class like this :
class Application : Application() {
override fun onCreate() {
super.onCreate()
retrofitClient = RetrofitClient.instance
//api url
.setBaseUrl("https://reqres.in/")
//you can set multiple urls
// .setUrl("example","http://ngrok.io/api/")
//set timeouts
.setConnectionTimeout(4)
.setReadingTimeout(15)
//enable cache
.enableCaching(this)
//add Headers
.addHeader("Content-Type", "application/json")
.addHeader("client", "android")
.addHeader("language", Locale.getDefault().language)
.addHeader("os", android.os.Build.VERSION.RELEASE)
}
companion object {
lateinit var retrofitClient: RetrofitClient
}
}
And then make your call:
retrofitClient.Get<GetResponseModel>()
//set path
.setPath("api/users/2")
//set url params Key-Value or HashMap
.setUrlParams("KEY","Value")
// you can add header here
.addHeaders("key","value")
.setResponseHandler(GetResponseModel::class.java,
object : ResponseHandler<GetResponseModel>() {
override fun onSuccess(response: Response<GetResponseModel>) {
super.onSuccess(response)
//handle response
}
}).run(this)
For more information see the documentation

Kotlin version would be
fun getHeaderInterceptor():Interceptor{
return object : Interceptor {
#Throws(IOException::class)
override fun intercept(chain: Interceptor.Chain): Response {
val request =
chain.request().newBuilder()
.header(Headers.KEY_AUTHORIZATION, "Bearer.....")
.build()
return chain.proceed(request)
}
}
}
private fun createOkHttpClient(): OkHttpClient {
return OkHttpClient.Builder()
.apply {
if(BuildConfig.DEBUG){
this.addInterceptor(HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.BASIC))
}
}
.addInterceptor(getHeaderInterceptor())
.build()
}

How to add headers to OkHttp request interceptor?

I have this interceptor that i add to my OkHttp client:
public class RequestTokenInterceptor implements Interceptor {
#Override
public Response intercept(Chain chain) throws IOException {
Request request = chain.request();
// Here where we'll try to refresh token.
// with an retrofit call
// After we succeed we'll proceed our request
Response response = chain.proceed(request);
return response;
}
}
How can i add headers to request in my interceptor?
I tried this but i am making mistake and i lose my request when creating new request:
public class RequestTokenInterceptor implements Interceptor {
#Override
public Response intercept(Interceptor.Chain chain) throws IOException {
Request request = chain.request();
Request newRequest;
try {
Log.d("addHeader", "Before");
String token = TokenProvider.getInstance(mContext).getToken();
newRequest = request.newBuilder()
.addHeader(HeadersContract.HEADER_AUTHONRIZATION, O_AUTH_AUTHENTICATION + token)
.addHeader(HeadersContract.HEADER_CLIENT_ID, CLIENT_ID)
.build();
} catch (Exception e) {
Log.d("addHeader", "Error");
e.printStackTrace();
return chain.proceed(request);
}
Log.d("addHeader", "after");
return chain.proceed(newRequest);
}
}
Note that, i know i can add header when creating request like this:
Request request = new Request.Builder()
.url("https://api.github.com/repos/square/okhttp/issues")
.header("User-Agent", "OkHttp Headers.java")
.addHeader("Accept", "application/json; q=0.5")
.addHeader("Accept", "application/vnd.github.v3+json")
.build();
But it doesn't fit my needs. I need it in interceptor.

Finally, I added the headers this way:
#Override
public Response intercept(Interceptor.Chain chain) throws IOException {
Request request = chain.request();
Request newRequest;
newRequest = request.newBuilder()
.addHeader(HeadersContract.HEADER_AUTHONRIZATION, O_AUTH_AUTHENTICATION)
.addHeader(HeadersContract.HEADER_X_CLIENT_ID, CLIENT_ID)
.build();
return chain.proceed(newRequest);
}

you can do it this way
private String GET(String url, Map<String, String> header) throws IOException {
Headers headerbuild = Headers.of(header);
Request request = new Request.Builder().url(url).headers(headerbuild).
build();
Response response = client.newCall(request).execute();
return response.body().string();
}

here is a useful gist from lfmingo
OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
httpClient.addInterceptor(new Interceptor() {
#Override
public Response intercept(Interceptor.Chain chain) throws IOException {
Request original = chain.request();
Request request = original.newBuilder()
.header("User-Agent", "Your-App-Name")
.header("Accept", "application/vnd.yourapi.v1.full+json")
.method(original.method(), original.body())
.build();
return chain.proceed(request);
}
}
OkHttpClient client = httpClient.build();
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(API_BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.client(client)
.build();

Faced similar issue with other samples, this Kotlin class worked for me
import okhttp3.Interceptor
import okhttp3.Response
class CustomInterceptor : Interceptor {
override fun intercept(chain: Interceptor.Chain) : Response {
val request = chain.request().newBuilder()
.header("x-custom-header", "my-value")
.build()
return chain.proceed(request)
}
}

If you are using Retrofit library then you can directly pass header to api request using #Header annotation without use of Interceptor. Here is example that shows how to add header to Retrofit api request.
#POST(apiURL)
void methodName(
#Header(HeadersContract.HEADER_AUTHONRIZATION) String token,
#Header(HeadersContract.HEADER_CLIENT_ID) String token,
#Body TypedInput body,
Callback<String> callback);
Hope it helps!

There is yet an another way to add interceptors in your OkHttp3 (latest version as of now) , that is you add the interceptors to your Okhttp builder
okhttpBuilder.networkInterceptors().add(chain -> {
//todo add headers etc to your AuthorisedRequest
return chain.proceed(yourAuthorisedRequest);
});
and finally build your okHttpClient from this builder
OkHttpClient client = builder.build();

Kotlin version:
fun okHttpClientFactory(): OkHttpClient {
return OkHttpClient().newBuilder()
.addInterceptor { chain ->
chain.request().newBuilder()
.addHeader(HEADER_AUTHONRIZATION, O_AUTH_AUTHENTICATION)
.build()
.let(chain::proceed)
}
.build()
}

This worked for me:
class JSONHeaderInterceptor : Interceptor {
override fun intercept(chain: Interceptor.Chain) : Response {
val request = chain.request().newBuilder()
.header("Content-Type", "application/json")
.build()
return chain.proceed(request)
}
}
fun provideHttpClient(): OkHttpClient {
val okHttpClientBuilder = OkHttpClient.Builder()
okHttpClientBuilder.addInterceptor(JSONHeaderInterceptor())
return okHttpClientBuilder.build()
}

package com.example.network.interceptors;
import androidx.annotation.NonNull;
import java.io.IOException;
import java.util.Map;
import okhttp3.Interceptor;
import okhttp3.Request;
import okhttp3.Response;
public class RequestHeadersNetworkInterceptor implements Interceptor {
private final Map<String, String> headers;
public RequestHeadersNetworkInterceptor(#NonNull Map<String, String> headers) {
this.headers = headers;
}
#NonNull
#Override
public Response intercept(Chain chain) throws IOException {
Request.Builder builder = chain.request().newBuilder();
for (Map.Entry<String, String> header : headers.entrySet()) {
if (header.getKey() == null || header.getKey().trim().isEmpty()) {
continue;
}
if (header.getValue() == null || header.getValue().trim().isEmpty()) {
builder.removeHeader(header.getKey());
} else {
builder.header(header.getKey(), header.getValue());
}
}
return chain.proceed(builder.build());
}
}
Example of usage:
httpClientBuilder.networkInterceptors().add(new RequestHeadersNetworkInterceptor(new HashMap<String, String>()
{
{
put("User-Agent", getUserAgent());
put("Accept", "application/json");
}
}));

client = new OkHttpClient();
Request request = new Request.Builder().header("authorization", token).url(url).build();
MyWebSocketListener wsListener = new MyWebSocketListener(LudoRoomActivity.this);
client.newWebSocket(request, wsListener);
client.dispatcher().executorService().shutdown();

For those to whom okhttp3 interceptor still does not work. Consequence of adding interceptors is make sense! Kotlin example
My interceptor:
class MyOkHttpInterceptor : Interceptor, Logging {
#Throws(IOException::class)
override fun intercept(chain: Interceptor.Chain): Response {
val mdc = MDC.getCopyOfContextMap()
var request = chain.request().newBuilder()
.header(CommonConstants.WS_USER_AGENT, CommonConstants.WS_USER_AGENT_SEARCH)
.header(CommonConstants.WS_HEADER_TRACED_ID, mdc[CommonConstants.WS_HEADER_TRACED_ID]!!)
.header(CommonConstants.WS_HEADER_ACCEPT, MediaType.APPLICATION_JSON_VALUE)
.method(chain.request().method, chain.request().body)
.build()
return chain.proceed(request)
}
}
My logging interceptor:
val interceptor = HttpLoggingInterceptor()
interceptor.level = HttpLoggingInterceptor.Level.BASIC
I am adding header interceptor
I am adding logging interceptor
Do not use network interceptors!!!
val client = OkHttpClient.Builder()
.connectTimeout(httpConnectTimeOut, TimeUnit.SECONDS)
.writeTimeout(httpConnectTimeOut, TimeUnit.SECONDS)
.readTimeout(readTimeOut, TimeUnit.SECONDS)
.addInterceptor(MyOkHttpInterceptor())
.addInterceptor(interceptor)
.build()

Add custom headers to WebView resource requests - android

I need to add custom headers to EVERY request coming from the WebView. I know loadURL has the parameter for extraHeaders, but those are only applied to the initial request. All subsequent requests do not contain the headers. I have looked at all overrides in WebViewClient, but nothing allows for adding headers to resource requests - onLoadResource(WebView view, String url). Any help would be wonderful.
Thanks,
Ray

Try
loadUrl(String url, Map<String, String> extraHeaders)
For adding headers to resources loading requests, make custom WebViewClient and override:
API 24+:
WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request)
or
WebResourceResponse shouldInterceptRequest(WebView view, String url)

You will need to intercept each request using WebViewClient.shouldInterceptRequest
With each interception, you will need to take the url, make this request yourself, and return the content stream:
WebViewClient wvc = new WebViewClient() {
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
try {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
httpGet.setHeader("MY-CUSTOM-HEADER", "header value");
httpGet.setHeader(HttpHeaders.USER_AGENT, "custom user-agent");
HttpResponse httpReponse = client.execute(httpGet);
Header contentType = httpReponse.getEntity().getContentType();
Header encoding = httpReponse.getEntity().getContentEncoding();
InputStream responseInputStream = httpReponse.getEntity().getContent();
String contentTypeValue = null;
String encodingValue = null;
if (contentType != null) {
contentTypeValue = contentType.getValue();
}
if (encoding != null) {
encodingValue = encoding.getValue();
}
return new WebResourceResponse(contentTypeValue, encodingValue, responseInputStream);
} catch (ClientProtocolException e) {
//return null to tell WebView we failed to fetch it WebView should try again.
return null;
} catch (IOException e) {
//return null to tell WebView we failed to fetch it WebView should try again.
return null;
}
}
}
Webview wv = new WebView(this);
wv.setWebViewClient(wvc);
If your minimum API target is level 21, you can use the new shouldInterceptRequest which gives you additional request information (such as headers) instead of just the URL.

Maybe my response quite late, but it covers API below and above 21 level.
To add headers we should intercept every request and create new one with required headers.
So we need to override shouldInterceptRequest method called in both cases:
1. for API until level 21;
2. for API level 21+
webView.setWebViewClient(new WebViewClient() {
// Handle API until level 21
#SuppressWarnings("deprecation")
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
return getNewResponse(url);
}
// Handle API 21+
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
String url = request.getUrl().toString();
return getNewResponse(url);
}
private WebResourceResponse getNewResponse(String url) {
try {
OkHttpClient httpClient = new OkHttpClient();
Request request = new Request.Builder()
.url(url.trim())
.addHeader("Authorization", "YOU_AUTH_KEY") // Example header
.addHeader("api-key", "YOUR_API_KEY") // Example header
.build();
Response response = httpClient.newCall(request).execute();
return new WebResourceResponse(
null,
response.header("content-encoding", "utf-8"),
response.body().byteStream()
);
} catch (Exception e) {
return null;
}
}
});
If response type should be processed you could change
return new WebResourceResponse(
null, // <- Change here
response.header("content-encoding", "utf-8"),
response.body().byteStream()
);
to
return new WebResourceResponse(
getMimeType(url), // <- Change here
response.header("content-encoding", "utf-8"),
response.body().byteStream()
);
and add method
private String getMimeType(String url) {
String type = null;
String extension = MimeTypeMap.getFileExtensionFromUrl(url);
if (extension != 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";
}
type = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
}
return type;
}

As mentioned before, you can do this:
WebView host = (WebView)this.findViewById(R.id.webView);
String url = "<yoururladdress>";
Map <String, String> extraHeaders = new HashMap<String, String>();
extraHeaders.put("Authorization","Bearer");
host.loadUrl(url,extraHeaders);
I tested this and on with a MVC Controller that I extended the Authorize Attribute to inspect the header and the header is there.

This works for me:
First you need to create method, which will be returns your
headers you want to add to request:
private Map<String, String> getCustomHeaders()
{
Map<String, String> headers = new HashMap<>();
headers.put("YOURHEADER", "VALUE");
return headers;
}
Second you need to create WebViewClient:
private WebViewClient getWebViewClient()
{
return new WebViewClient()
{
#Override
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request)
{
view.loadUrl(request.getUrl().toString(), getCustomHeaders());
return true;
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url)
{
view.loadUrl(url, getCustomHeaders());
return true;
}
};
}
Add WebViewClient to your WebView:
webView.setWebViewClient(getWebViewClient());
Hope this helps.

You should be able to control all your headers by skipping loadUrl and writing your own loadPage using Java's HttpURLConnection. Then use the webview's loadData to display the response.
There is no access to the headers which Google provides. They are in a JNI call, deep in the WebView source.

Here is an implementation using HttpUrlConnection:
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
}
}
Note that this does not work for POST requests because WebResourceRequest doesn't provide POST data. There is a Request Data - WebViewClient library which uses a JavaScript injection workaround for intercepting POST data.

This worked for me. Create WebViewClient like this below and set the webclient to your webview. I had to use webview.loadDataWithBaseURL as my urls (in my content) did not have the baseurl but only relative urls. You will get the url correctly only when there is a baseurl set using loadDataWithBaseURL.
public WebViewClient getWebViewClientWithCustomHeader(){
return new WebViewClient() {
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
try {
OkHttpClient httpClient = new OkHttpClient();
com.squareup.okhttp.Request request = new com.squareup.okhttp.Request.Builder()
.url(url.trim())
.addHeader("<your-custom-header-name>", "<your-custom-header-value>")
.build();
com.squareup.okhttp.Response response = httpClient.newCall(request).execute();
return new WebResourceResponse(
response.header("content-type", response.body().contentType().type()), // You can set something other as default content-type
response.header("content-encoding", "utf-8"), // Again, you can set another encoding as default
response.body().byteStream()
);
} catch (ClientProtocolException e) {
//return null to tell WebView we failed to fetch it WebView should try again.
return null;
} catch (IOException e) {
//return null to tell WebView we failed to fetch it WebView should try again.
return null;
}
}
};
}

You can use this:
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// Here put your code
Map<String, String> map = new HashMap<String, String>();
map.put("Content-Type","application/json");
view.loadUrl(url, map);
return false;
}

I came accross the same problem and solved.
As said before you need to create your custom WebViewClient and override the shouldInterceptRequest method.
WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request)
That method should issue a webView.loadUrl while returning an "empty" WebResourceResponse.
Something like this:
#Override
public boolean shouldInterceptRequest(WebView view, WebResourceRequest request) {
// Check for "recursive request" (are yor header set?)
if (request.getRequestHeaders().containsKey("Your Header"))
return null;
// Add here your headers (could be good to import original request header here!!!)
Map<String, String> customHeaders = new HashMap<String, String>();
customHeaders.put("Your Header","Your Header Value");
view.loadUrl(url, customHeaders);
return new WebResourceResponse("", "", null);
}

Use this:
webView.getSettings().setUserAgentString("User-Agent");