Add support for sending additional headers with put requests (#66)

* Add support for sending additional headers with put requests

* Rename extraHeaders param to headers

* Add support for custom headers in delete requests

Author: sunkup

src/main/kotlin/at/bitfire/dav4jvm/DavResource.kt

@@ -439,14 +439,22 @@ open class DavResource @JvmOverloads constructor(
      * @param ifETag        value of `If-Match` header to set, or null to omit
      * @param ifScheduleTag value of `If-Schedule-Tag-Match` header to set, or null to omit
      * @param ifNoneMatch   indicates whether `If-None-Match: *` ("don't overwrite anything existing") header shall be sent
+     * @param headers       additional headers to send
      * @param callback      called with server response unless an exception is thrown
      *
      * @throws IOException on I/O error
      * @throws HttpException on HTTP error
      * @throws DavException on HTTPS -> HTTP redirect
      */
     @Throws(IOException::class, HttpException::class)
-    fun put(body: RequestBody, ifETag: String? = null, ifScheduleTag: String? = null, ifNoneMatch: Boolean = false, callback: ResponseCallback) {
+    fun put(
+        body: RequestBody,
+        ifETag: String? = null,
+        ifScheduleTag: String? = null,
+        ifNoneMatch: Boolean = false,
+        headers: Map<String, String> = emptyMap(),
+        callback: ResponseCallback
+    ) {
         followRedirects {
             val builder = Request.Builder()
                     .put(body)
@@ -462,6 +470,10 @@ open class DavResource @JvmOverloads constructor(
                 // don't overwrite anything existing
                 builder.header("If-None-Match", "*")
 
+            // Add custom headers
+            for ((key, value) in headers)
+                builder.header(key, value)
+
             httpClient.newCall(builder.build()).execute()
         }.use { response ->
             checkStatus(response)
@@ -477,6 +489,7 @@ open class DavResource @JvmOverloads constructor(
      *
      * @param ifETag        value of `If-Match` header to set, or null to omit
      * @param ifScheduleTag value of `If-Schedule-Tag-Match` header to set, or null to omit
+     * @param headers       additional headers to send
      * @param callback      called with server response unless an exception is thrown
      *
      * @throws IOException on I/O error
@@ -485,7 +498,12 @@ open class DavResource @JvmOverloads constructor(
      * @throws DavException on HTTPS -> HTTP redirect
      */
     @Throws(IOException::class, HttpException::class)
-    fun delete(ifETag: String? = null, ifScheduleTag: String? = null, callback: ResponseCallback) {
+    fun delete(
+        ifETag: String? = null,
+        ifScheduleTag: String? = null,
+        headers: Map<String, String> = emptyMap(),
+        callback: ResponseCallback
+    ) {
         followRedirects {
             val builder = Request.Builder()
                     .delete()
@@ -495,6 +513,10 @@ open class DavResource @JvmOverloads constructor(
             if (ifScheduleTag != null)
                 builder.header("If-Schedule-Tag-Match", QuotedStringUtils.asQuotedString(ifScheduleTag))
 
+            // Add custom headers
+            for ((key, value) in headers)
+                builder.header(key, value)
+
             httpClient.newCall(builder.build()).execute()
         }.use { response ->
             checkStatus(response)