Added in API level 1

HttpURLConnection

abstract class HttpURLConnection : URLConnection

kotlin.Any
↳	java.net.URLConnection
	↳	java.net.HttpURLConnection

Known Direct Subclasses

HttpsURLConnection

HttpsURLConnection extends HttpURLConnection with support for https-specific features.

A URLConnection with support for HTTP-specific features. See the spec for details.

Uses of this class follow a pattern:

Obtain a new HttpURLConnection by calling URL.openConnection() and casting the result to HttpURLConnection.
Prepare the request. The primary property of a request is its URI. Request headers may also include metadata such as credentials, preferred content types, and session cookies.
Optionally upload a request body. Instances must be configured with setDoOutput(true) if they include a request body. Transmit data by writing to the stream returned by getOutputStream().
Read the response. Response headers typically include metadata such as the response body's content type and length, modified dates and session cookies. The response body may be read from the stream returned by getInputStream(). If the response has no body, that method returns an empty stream.
Disconnect. Once the response body has been read, the HttpURLConnection should be closed by calling disconnect(). Disconnecting releases the resources held by a connection so they may be closed or reused.

For example, to retrieve the webpage at http://www.android.com/:

<code>URL url = new URL("http://www.android.com/");
    HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
    try {
      InputStream in = new BufferedInputStream(urlConnection.getInputStream());
      readStream(in);
    } finally {
      urlConnection.disconnect();
    }
  </code>

Secure Communication with HTTPS

Calling URL.openConnection() on a URL with the "https" scheme will return an HttpsURLConnection, which allows for overriding the default HostnameVerifier and SSLSocketFactory. An application-supplied SSLSocketFactory created from an SSLContext can provide a custom X509TrustManager for verifying certificate chains and a custom X509KeyManager for supplying client certificates. See HttpsURLConnection for more details.

Response Handling

HttpURLConnection will follow up to five HTTP redirects. It will follow redirects from one origin server to another. This implementation doesn't follow redirects from HTTPS to HTTP or vice versa.

If the HTTP response indicates that an error occurred, getInputStream() will throw an IOException. Use getErrorStream() to read the error response. The headers can be read in the normal way using getHeaderFields(),

Posting Content

To upload data to a web server, configure the connection for output using setDoOutput(true).

For best performance, you should call either setFixedLengthStreamingMode(int) when the body length is known in advance, or setChunkedStreamingMode(int) when it is not. Otherwise HttpURLConnection will be forced to buffer the complete request body in memory before it is transmitted, wasting (and possibly exhausting) heap and increasing latency.

For example, to perform an upload:

<code>HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
    try {
      urlConnection.setDoOutput(true);
      urlConnection.setChunkedStreamingMode(0);
 
      OutputStream out = new BufferedOutputStream(urlConnection.getOutputStream());
      writeStream(out);
 
      InputStream in = new BufferedInputStream(urlConnection.getInputStream());
      readStream(in);
    } finally {
      urlConnection.disconnect();
    }
  </code>

Performance

The input and output streams returned by this class are not buffered. Most callers should wrap the returned streams with or . Callers that do only bulk reads or writes may omit buffering.

When transferring large amounts of data to or from a server, use streams to limit how much data is in memory at once. Unless you need the entire body to be in memory at once, process it as a stream (rather than storing the complete body as a single byte array or string).

To reduce latency, this class may reuse the same underlying Socket for multiple request/response pairs. As a result, HTTP connections may be held open longer than necessary. Calls to disconnect() may return the socket to a pool of connected sockets.

By default, this implementation of HttpURLConnection requests that servers use gzip compression and it automatically decompresses the data for callers of getInputStream(). The Content-Encoding and Content-Length response headers are cleared in this case. Gzip compression can be disabled by setting the acceptable encodings in the request header:

<code>urlConnection.setRequestProperty("Accept-Encoding", "identity");
  </code>

Setting the Accept-Encoding request header explicitly disables automatic decompression and leaves the response headers intact; callers must handle decompression as needed, according to the Content-Encoding header of the response.

getContentLength() returns the number of bytes transmitted and cannot be used to predict how many bytes can be read from getInputStream() for compressed streams. Instead, read that stream until it is exhausted, i.e. when java.io.InputStream#read returns -1.

Handling Network Sign-On

Some Wi-Fi networks block Internet access until the user clicks through a sign-on page. Such sign-on pages are typically presented by using HTTP redirects. You can use getURL() to test if your connection has been unexpectedly redirected. This check is not valid until after the response headers have been received, which you can trigger by calling getHeaderFields() or getInputStream(). For example, to check that a response was not redirected to an unexpected host:

<code>HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
    try {
      InputStream in = new BufferedInputStream(urlConnection.getInputStream());
      if (!url.getHost().equals(urlConnection.getURL().getHost())) {
        // we were redirected! Kick the user out to the browser to sign on?
      }
      ...
    } finally {
      urlConnection.disconnect();
    }
  </code>

HTTP Authentication

HttpURLConnection supports HTTP basic authentication. Use Authenticator to set the VM-wide authentication handler:

<code>Authenticator.setDefault(new Authenticator() {
      protected PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication(username, password.toCharArray());
      }
    });
  </code>

Unless paired with HTTPS, this is not a secure mechanism for user authentication. In particular, the username, password, request and response are all transmitted over the network without encryption.

Sessions with Cookies

To establish and maintain a potentially long-lived session between client and server, HttpURLConnection includes an extensible cookie manager. Enable VM-wide cookie management using CookieHandler and CookieManager:

<code>CookieManager cookieManager = new CookieManager();
    CookieHandler.setDefault(cookieManager);
  </code>

By default, CookieManager accepts cookies from the origin server only. Two other policies are included: java.net.CookiePolicy#ACCEPT_ALL and CookiePolicy.ACCEPT_NONE. Implement CookiePolicy to define a custom policy.

The default CookieManager keeps all accepted cookies in memory. It will forget these cookies when the VM exits. Implement CookieStore to define a custom cookie store.

In addition to the cookies set by HTTP responses, you may set cookies programmatically. To be included in HTTP request headers, cookies must have the domain and path properties set.

By default, new instances of HttpCookie work only with servers that support RFC 2965 cookies. Many web servers support only the older specification, RFC 2109. For compatibility with the most web servers, set the cookie version to 0.

For example, to receive www.twitter.com in French:

<code>HttpCookie cookie = new HttpCookie("lang", "fr");
    cookie.setDomain("twitter.com");
    cookie.setPath("/");
    cookie.setVersion(0);
    cookieManager.getCookieStore().add(new URI("http://twitter.com/"), cookie);
  </code>

HTTP Methods

HttpURLConnection uses the GET method by default. It will use POST if setDoOutput(true) has been called. Other HTTP methods (OPTIONS, HEAD, PUT, DELETE and TRACE) can be used with setRequestMethod.

Proxies

By default, this class will connect directly to the origin server. It can also connect via an HTTP or SOCKS proxy. To use a proxy, use URL.openConnection(Proxy) when creating the connection.

IPv6 Support

This class includes transparent support for IPv6. For hosts with both IPv4 and IPv6 addresses, it will attempt to connect to each of a host's addresses until a connection is established.

Response Caching

Android 4.0 (Ice Cream Sandwich, API level 15) includes a response cache. See android.net.http.HttpResponseCache for instructions on enabling HTTP caching in your application.

Avoiding Bugs In Earlier Releases

Prior to Android 2.2 (Froyo), this class had some frustrating bugs. In particular, calling close() on a readable InputStream could poison the connection pool. Work around this by disabling connection pooling:

<code>private void disableConnectionReuseIfNecessary() {
    // Work around pre-Froyo bugs in HTTP connection reuse.
    if (Integer.parseInt(Build.VERSION.SDK) &lt; Build.VERSION_CODES.FROYO) {
      System.setProperty("http.keepAlive", "false");
    }
  }</code>

Each instance of HttpURLConnection may be used for one request/response pair. Instances of this class are not thread safe.

Summary

Constants
static Int	`HTTP_ACCEPTED` HTTP Status-Code 202: Accepted.
static Int	`HTTP_BAD_GATEWAY` HTTP Status-Code 502: Bad Gateway.
static Int	`HTTP_BAD_METHOD` HTTP Status-Code 405: Method Not Allowed.
static Int	`HTTP_BAD_REQUEST` HTTP Status-Code 400: Bad Request.
static Int	`HTTP_CLIENT_TIMEOUT` HTTP Status-Code 408: Request Time-Out.
static Int	`HTTP_CONFLICT` HTTP Status-Code 409: Conflict.
static Int	`HTTP_CREATED` HTTP Status-Code 201: Created.
static Int	`HTTP_ENTITY_TOO_LARGE` HTTP Status-Code 413: Request Entity Too Large.
static Int	`HTTP_FORBIDDEN` HTTP Status-Code 403: Forbidden.
static Int	`HTTP_GATEWAY_TIMEOUT` HTTP Status-Code 504: Gateway Timeout.
static Int	`HTTP_GONE` HTTP Status-Code 410: Gone.
static Int	`HTTP_INTERNAL_ERROR` HTTP Status-Code 500: Internal Server Error.
static Int	`HTTP_LENGTH_REQUIRED` HTTP Status-Code 411: Length Required.
static Int	`HTTP_MOVED_PERM` HTTP Status-Code 301: Moved Permanently.
static Int	`HTTP_MOVED_TEMP` HTTP Status-Code 302: Temporary Redirect.
static Int	`HTTP_MULT_CHOICE` HTTP Status-Code 300: Multiple Choices.
static Int	`HTTP_NOT_ACCEPTABLE` HTTP Status-Code 406: Not Acceptable.
static Int	`HTTP_NOT_AUTHORITATIVE` HTTP Status-Code 203: Non-Authoritative Information.
static Int	`HTTP_NOT_FOUND` HTTP Status-Code 404: Not Found.
static Int	`HTTP_NOT_IMPLEMENTED` HTTP Status-Code 501: Not Implemented.
static Int	`HTTP_NOT_MODIFIED` HTTP Status-Code 304: Not Modified.
static Int	`HTTP_NO_CONTENT` HTTP Status-Code 204: No Content.
static Int	`HTTP_OK` HTTP Status-Code 200: OK.
static Int	`HTTP_PARTIAL` HTTP Status-Code 206: Partial Content.
static Int	`HTTP_PAYMENT_REQUIRED` HTTP Status-Code 402: Payment Required.
static Int	`HTTP_PRECON_FAILED` HTTP Status-Code 412: Precondition Failed.
static Int	`HTTP_PROXY_AUTH` HTTP Status-Code 407: Proxy Authentication Required.
static Int	`HTTP_REQ_TOO_LONG` HTTP Status-Code 414: Request-URI Too Large.
static Int	`HTTP_RESET` HTTP Status-Code 205: Reset Content.
static Int	`HTTP_SEE_OTHER` HTTP Status-Code 303: See Other.
static Int	`HTTP_SERVER_ERROR` HTTP Status-Code 500: Internal Server Error.
static Int	`HTTP_UNAUTHORIZED` HTTP Status-Code 401: Unauthorized.
static Int	`HTTP_UNAVAILABLE` HTTP Status-Code 503: Service Unavailable.
static Int	`HTTP_UNSUPPORTED_TYPE` HTTP Status-Code 415: Unsupported Media Type.
static Int	`HTTP_USE_PROXY` HTTP Status-Code 305: Use Proxy.
static Int	`HTTP_VERSION` HTTP Status-Code 505: HTTP Version Not Supported.

Protected constructors
`HttpURLConnection(u: URL!)` Constructor for the HttpURLConnection.

Public methods
abstract Unit	`disconnect()` Indicates that other requests to the server are unlikely in the near future.
open InputStream!	`getErrorStream()` Returns the error stream if the connection failed but the server sent useful data nonetheless.
open static Boolean	`getFollowRedirects()` Returns a `boolean` indicating whether or not HTTP redirects (3xx) should be automatically followed.
open String!	`getHeaderField(n: Int)` Returns the value for the `n`th header field.
open Long	`getHeaderFieldDate(name: String!, Default: Long)`
open String!	`getHeaderFieldKey(n: Int)` Returns the key for the `n`th header field.
open Boolean	`getInstanceFollowRedirects()` Returns the value of this `HttpURLConnection`'s `instanceFollowRedirects` field.
open Permission!	`getPermission()` Returns a `SocketPermission` object representing the permission necessary to connect to the destination host and port.
open String!	`getRequestMethod()` Get the request method.
open Int	`getResponseCode()` Gets the status code from an HTTP response message.
open String!	`getResponseMessage()` Gets the HTTP response message, if any, returned along with the response code from a server.
open Unit	`setChunkedStreamingMode(chunklen: Int)` This method is used to enable streaming of a HTTP request body without internal buffering, when the content length is not known in advance.
open Unit	`setFixedLengthStreamingMode(contentLength: Int)` This method is used to enable streaming of a HTTP request body without internal buffering, when the content length is known in advance.
open Unit	`setFixedLengthStreamingMode(contentLength: Long)` This method is used to enable streaming of a HTTP request body without internal buffering, when the content length is known in advance.
open static Unit	`setFollowRedirects(set: Boolean)` Sets whether HTTP redirects (requests with response code 3xx) should be automatically followed by this class.
open Unit	`setInstanceFollowRedirects(followRedirects: Boolean)` Sets whether HTTP redirects (requests with response code 3xx) should be automatically followed by this `HttpURLConnection` instance.
open Unit	`setRequestMethod(method: String!)` Set the method for the URL request, one of: GET POST HEAD OPTIONS PUT DELETE TRACE are legal, subject to protocol restrictions.
abstract Boolean	`usingProxy()` Indicates if the connection is going through a proxy.

Inherited functions

From class URLConnection

`Unit`	`addRequestProperty(key: String!, value: String!)` Adds a general request property specified by a key-value pair. This method will not overwrite existing values associated with the same key.
`Unit`	`connect()` Opens a communications link to the resource referenced by this URL, if such a connection has not already been established. If the `connect` method is called when the connection has already been opened (indicated by the `connected` field having the value `true`), the call is ignored. URLConnection objects go through two phases: first they are created, then they are connected. After being created, and before being connected, various options can be specified (e.g., doInput and UseCaches). After connecting, it is an error to try to set them. Operations that depend on being connected, like getContentLength, will implicitly perform the connection, if necessary.
`Boolean`	`getAllowUserInteraction()` Returns the value of the `allowUserInteraction` field for this object.
`Int`	`getConnectTimeout()` Returns setting for connect timeout. 0 return implies that the option is disabled (i.e., timeout of infinity).
`Any!`	`getContent()` Retrieves the contents of this URL connection. This method first determines the content type of the object by calling the `getContentType` method. If this is the first time that the application has seen that specific content type, a content handler for that content type is created: If the application has set up a content handler factory instance using the `setContentHandlerFactory` method, the `createContentHandler` method of that instance is called with the content type as an argument; the result is a content handler for that content type. If no content handler factory has yet been set up, or if the factory's `createContentHandler` method returns `null`, then the application loads the class named: sun.net.www.content.<<i>contentType</i>> where <contentType> is formed by taking the content-type string, replacing all slash characters with a `period` ('.'), and all other non-alphanumeric characters with the underscore character '`_`'. The alphanumeric characters are specifically the 26 uppercase ASCII letters '`A`' through '`Z`', the 26 lowercase ASCII letters '`a`' through '`z`', and the 10 ASCII digits '`0`' through '`9`'. If the specified class does not exist, or is not a subclass of `ContentHandler`, then an `UnknownServiceException` is thrown.
`Any!`	`getContent(classes: Array<Class<Any!>!>!)` Retrieves the contents of this URL connection.
`String!`	`getContentEncoding()` Returns the value of the `content-encoding` header field.
`Int`	`getContentLength()` Returns the value of the `content-length` header field. Note: `getContentLengthLong()` should be preferred over this method, since it returns a `long` instead and is therefore more portable.
`Long`	`getContentLengthLong()` Returns the value of the `content-length` header field as a long.
`String!`	`getContentType()` Returns the value of the `content-type` header field.
`Long`	`getDate()` Returns the value of the `date` header field.
`Boolean`	`getDefaultAllowUserInteraction()` Returns the default value of the `allowUserInteraction` field. Ths default is "sticky", being a part of the static state of all URLConnections. This flag applies to the next, and all following URLConnections that are created.
`String!`	`getDefaultRequestProperty(key: String!)` Returns the value of the default request property. Default request properties are set for every connection.
`Boolean`	`getDefaultUseCaches()` Returns the default value of a `URLConnection`'s `useCaches` flag. Ths default is "sticky", being a part of the static state of all URLConnections. This flag applies to the next, and all following URLConnections that are created.
`Boolean`	`getDoInput()` Returns the value of this `URLConnection`'s `doInput` flag.
`Boolean`	`getDoOutput()` Returns the value of this `URLConnection`'s `doOutput` flag.
`Long`	`getExpiration()` Returns the value of the `expires` header field.
`FileNameMap!`	`getFileNameMap()` Returns a `FileNameMap` implementation suitable for guessing a content type based on a URL's "file" component.
`String!`	`getHeaderField(name: String!)` Returns the value of the named header field. If called on a connection that sets the same header multiple times with possibly different values, only the last value is returned.
`Int`	`getHeaderFieldInt(name: String!, Default: Int)` Returns the value of the named field parsed as a number. This form of `getHeaderField` exists because some connection types (e.g., `http-ng`) have pre-parsed headers. Classes for that connection type can override this method and short-circuit the parsing.
`Long`	`getHeaderFieldLong(name: String!, Default: Long)` Returns the value of the named field parsed as a number. This form of `getHeaderField` exists because some connection types (e.g., `http-ng`) have pre-parsed headers. Classes for that connection type can override this method and short-circuit the parsing.
`MutableMap<String!, MutableList<String!>!>!`	`getHeaderFields()` Returns an unmodifiable Map of the header fields. The Map keys are Strings that represent the response-header field names. Each Map value is an unmodifiable List of Strings that represents the corresponding field values.
`Long`	`getIfModifiedSince()` Returns the value of this object's `ifModifiedSince` field.
`InputStream!`	`getInputStream()` Returns an input stream that reads from this open connection. A SocketTimeoutException can be thrown when reading from the returned input stream if the read timeout expires before data is available for read.
`Long`	`getLastModified()` Returns the value of the `last-modified` header field. The result is the number of milliseconds since January 1, 1970 GMT.
`OutputStream!`	`getOutputStream()` Returns an output stream that writes to this connection.
`Int`	`getReadTimeout()` Returns setting for read timeout. 0 return implies that the option is disabled (i.e., timeout of infinity).
`MutableMap<String!, MutableList<String!>!>!`	`getRequestProperties()` Returns an unmodifiable Map of general request properties for this connection. The Map keys are Strings that represent the request-header field names. Each Map value is a unmodifiable List of Strings that represents the corresponding field values.
`String!`	`getRequestProperty(key: String!)` Returns the value of the named general request property for this connection.
`URL!`	`getURL()` Returns the value of this `URLConnection`'s `URL` field.
`Boolean`	`getUseCaches()` Returns the value of this `URLConnection`'s `useCaches` field.
`String!`	`guessContentTypeFromName(fname: String!)` Tries to determine the content type of an object, based on the specified "file" component of a URL. This is a convenience method that can be used by subclasses that override the `getContentType` method.
`String!`	`guessContentTypeFromStream(is: InputStream!)` Tries to determine the type of an input stream based on the characters at the beginning of the input stream. This method can be used by subclasses that override the `getContentType` method. Ideally, this routine would not be needed. But many `http` servers return the incorrect content type; in addition, there are many nonstandard extensions. Direct inspection of the bytes to determine the content type is often more accurate than believing the content type claimed by the `http` server.
`Unit`	`setAllowUserInteraction(allowuserinteraction: Boolean)` Set the value of the `allowUserInteraction` field of this `URLConnection`.
`Unit`	`setConnectTimeout(timeout: Int)` Sets a specified timeout value, in milliseconds, to be used when opening a communications link to the resource referenced by this URLConnection. If the timeout expires before the connection can be established, a java.net.SocketTimeoutException is raised. A timeout of zero is interpreted as an infinite timeout. Some non-standard implementation of this method may ignore the specified timeout. To see the connect timeout set, please call getConnectTimeout(). Warning: If the hostname resolves to multiple IP addresses, Android's default implementation of `HttpURLConnection` will try each in RFC 3484 order. If connecting to each of these addresses fails, multiple timeouts will elapse before the connect attempt throws an exception. Host names that support both IPv6 and IPv4 always have at least 2 IP addresses.
`Unit`	`setContentHandlerFactory(fac: ContentHandlerFactory!)` Sets the `ContentHandlerFactory` of an application. It can be called at most once by an application. The `ContentHandlerFactory` instance is used to construct a content handler from a content type If there is a security manager, this method first calls the security manager's `checkSetFactory` method to ensure the operation is allowed. This could result in a SecurityException.
`Unit`	`setDefaultAllowUserInteraction(defaultallowuserinteraction: Boolean)` Sets the default value of the `allowUserInteraction` field for all future `URLConnection` objects to the specified value.
`Unit`	`setDefaultRequestProperty(key: String!, value: String!)` Sets the default value of a general request property. When a `URLConnection` is created, it is initialized with these properties.
`Unit`	`setDefaultUseCaches(defaultusecaches: Boolean)` Sets the default value of the `useCaches` field to the specified value.
`Unit`	`setDoInput(doinput: Boolean)` Sets the value of the `doInput` field for this `URLConnection` to the specified value. A URL connection can be used for input and/or output. Set the DoInput flag to true if you intend to use the URL connection for input, false if not. The default is true.
`Unit`	`setDoOutput(dooutput: Boolean)` Sets the value of the `doOutput` field for this `URLConnection` to the specified value. A URL connection can be used for input and/or output. Set the DoOutput flag to true if you intend to use the URL connection for output, false if not. The default is false.
`Unit`	`setFileNameMap(map: FileNameMap!)` Sets the FileNameMap. If there is a security manager, this method first calls the security manager's `checkSetFactory` method to ensure the operation is allowed. This could result in a SecurityException.
`Unit`	`setIfModifiedSince(ifmodifiedsince: Long)` Sets the value of the `ifModifiedSince` field of this `URLConnection` to the specified value.
`Unit`	`setReadTimeout(timeout: Int)` Sets the read timeout to a specified timeout, in milliseconds. A non-zero value specifies the timeout when reading from Input stream when a connection is established to a resource. If the timeout expires before there is data available for read, a java.net.SocketTimeoutException is raised. A timeout of zero is interpreted as an infinite timeout. Some non-standard implementation of this method ignores the specified timeout. To see the read timeout set, please call getReadTimeout().
`Unit`	`setRequestProperty(key: String!, value: String!)` Sets the general request property. If a property with the key already exists, overwrite its value with the new value. NOTE: HTTP requires all request properties which can legally have multiple instances with the same key to use a comma-separated list syntax which enables multiple properties to be appended into a single property.
`Unit`	`setUseCaches(usecaches: Boolean)` Sets the value of the `useCaches` field of this `URLConnection` to the specified value. Some protocols do caching of documents. Occasionally, it is important to be able to "tunnel through" and ignore the caches (e.g., the "reload" button in a browser). If the UseCaches flag on a connection is true, the connection is allowed to use whatever caches it can. If false, caches are to be ignored. The default value comes from DefaultUseCaches, which defaults to true.
`String`	`toString()` Returns a `String` representation of this URL connection.

Properties
Int	`chunkLength` The chunk-length when using chunked encoding streaming mode for output.
Int	`fixedContentLength` The fixed content-length when using fixed-length streaming mode.
Long	`fixedContentLengthLong` The fixed content-length when using fixed-length streaming mode.
Boolean	`instanceFollowRedirects` If `true`, the protocol will automatically follow redirects.
String!	`method` The HTTP method (GET,POST,PUT,etc.).
Int	`responseCode` An `int` representing the three digit HTTP Status-Code.
String!	`responseMessage` The HTTP response message.

Inherited properties

From class URLConnection

`Boolean`	`allowUserInteraction` If `true`, this `URL` is being examined in a context in which it makes sense to allow user interactions such as popping up an authentication dialog. If `false`, then no user interaction is allowed. The value of this field can be set by the `setAllowUserInteraction` method. Its value is returned by the `getAllowUserInteraction` method. Its default value is the value of the argument in the last invocation of the `setDefaultAllowUserInteraction` method.
`Boolean`	`connected` If `false`, this connection object has not created a communications link to the specified URL. If `true`, the communications link has been established.
`Boolean`	`doInput` This variable is set by the `setDoInput` method. Its value is returned by the `getDoInput` method. A URL connection can be used for input and/or output. Setting the `doInput` flag to `true` indicates that the application intends to read data from the URL connection. The default value of this field is `true`.
`Boolean`	`doOutput` This variable is set by the `setDoOutput` method. Its value is returned by the `getDoOutput` method. A URL connection can be used for input and/or output. Setting the `doOutput` flag to `true` indicates that the application intends to write data to the URL connection. The default value of this field is `false`.
`Long`	`ifModifiedSince` Some protocols support skipping the fetching of the object unless the object has been modified more recently than a certain time. A nonzero value gives a time as the number of milliseconds since January 1, 1970, GMT. The object is fetched only if it has been modified more recently than that time. This variable is set by the `setIfModifiedSince` method. Its value is returned by the `getIfModifiedSince` method. The default value of this field is `0`, indicating that the fetching must always occur.
`URL!`	`url` The URL represents the remote object on the World Wide Web to which this connection is opened. The value of this field can be accessed by the `getURL` method. The default value of this variable is the value of the URL argument in the `URLConnection` constructor.
`Boolean`	`useCaches` If `true`, the protocol is allowed to use caching whenever it can. If `false`, the protocol must always try to get a fresh copy of the object. This field is set by the `setUseCaches` method. Its value is returned by the `getUseCaches` method. Its default value is the value given in the last invocation of the `setDefaultUseCaches` method.

Constants

HTTP_ACCEPTED

Added in API level 1

static val HTTP_ACCEPTED: Int

HTTP Status-Code 202: Accepted.

Value: 202

HTTP_BAD_GATEWAY

Added in API level 1

static val HTTP_BAD_GATEWAY: Int

HTTP Status-Code 502: Bad Gateway.

Value: 502

HTTP_BAD_METHOD

Added in API level 1

static val HTTP_BAD_METHOD: Int

HTTP Status-Code 405: Method Not Allowed.

Value: 405

HTTP_BAD_REQUEST

Added in API level 1

static val HTTP_BAD_REQUEST: Int

HTTP Status-Code 400: Bad Request.

Value: 400

HTTP_CLIENT_TIMEOUT

Added in API level 1

static val HTTP_CLIENT_TIMEOUT: Int

HTTP Status-Code 408: Request Time-Out.

Value: 408

HTTP_CONFLICT

Added in API level 1

static val HTTP_CONFLICT: Int

HTTP Status-Code 409: Conflict.

Value: 409

HTTP_CREATED

Added in API level 1

static val HTTP_CREATED: Int

HTTP Status-Code 201: Created.

Value: 201

HTTP_ENTITY_TOO_LARGE

Added in API level 1

static val HTTP_ENTITY_TOO_LARGE: Int

HTTP Status-Code 413: Request Entity Too Large.

Value: 413

HTTP_FORBIDDEN

Added in API level 1

static val HTTP_FORBIDDEN: Int

HTTP Status-Code 403: Forbidden.

Value: 403

HTTP_GATEWAY_TIMEOUT

Added in API level 1

static val HTTP_GATEWAY_TIMEOUT: Int

HTTP Status-Code 504: Gateway Timeout.

Value: 504

HTTP_GONE

Added in API level 1

static val HTTP_GONE: Int

HTTP Status-Code 410: Gone.

Value: 410

HTTP_INTERNAL_ERROR

Added in API level 1

static val HTTP_INTERNAL_ERROR: Int

HTTP Status-Code 500: Internal Server Error.

Value: 500

HTTP_LENGTH_REQUIRED

Added in API level 1

static val HTTP_LENGTH_REQUIRED: Int

HTTP Status-Code 411: Length Required.

Value: 411

HTTP_MOVED_PERM

Added in API level 1

static val HTTP_MOVED_PERM: Int

HTTP Status-Code 301: Moved Permanently.

Value: 301

HTTP_MOVED_TEMP

Added in API level 1

static val HTTP_MOVED_TEMP: Int

HTTP Status-Code 302: Temporary Redirect.

Value: 302

HTTP_MULT_CHOICE

Added in API level 1

static val HTTP_MULT_CHOICE: Int

HTTP Status-Code 300: Multiple Choices.

Value: 300

HTTP_NOT_ACCEPTABLE

Added in API level 1

static val HTTP_NOT_ACCEPTABLE: Int

HTTP Status-Code 406: Not Acceptable.

Value: 406

HTTP_NOT_AUTHORITATIVE

Added in API level 1

static val HTTP_NOT_AUTHORITATIVE: Int

HTTP Status-Code 203: Non-Authoritative Information.

Value: 203

HTTP_NOT_FOUND

Added in API level 1

static val HTTP_NOT_FOUND: Int

HTTP Status-Code 404: Not Found.

Value: 404

HTTP_NOT_IMPLEMENTED

Added in API level 1

static val HTTP_NOT_IMPLEMENTED: Int

HTTP Status-Code 501: Not Implemented.

Value: 501

HTTP_NOT_MODIFIED

Added in API level 1

static val HTTP_NOT_MODIFIED: Int

HTTP Status-Code 304: Not Modified.

Value: 304

HTTP_NO_CONTENT

Added in API level 1

static val HTTP_NO_CONTENT: Int

HTTP Status-Code 204: No Content.

Value: 204

HTTP_OK

Added in API level 1

static val HTTP_OK: Int

HTTP Status-Code 200: OK.

Value: 200

HTTP_PARTIAL

Added in API level 1

static val HTTP_PARTIAL: Int

HTTP Status-Code 206: Partial Content.

Value: 206

HTTP_PAYMENT_REQUIRED

Added in API level 1

static val HTTP_PAYMENT_REQUIRED: Int

HTTP Status-Code 402: Payment Required.

Value: 402

HTTP_PRECON_FAILED

Added in API level 1

static val HTTP_PRECON_FAILED: Int

HTTP Status-Code 412: Precondition Failed.

Value: 412

HTTP_PROXY_AUTH

Added in API level 1

static val HTTP_PROXY_AUTH: Int

HTTP Status-Code 407: Proxy Authentication Required.

Value: 407

HTTP_REQ_TOO_LONG

Added in API level 1

static val HTTP_REQ_TOO_LONG: Int

HTTP Status-Code 414: Request-URI Too Large.

Value: 414

HTTP_RESET

Added in API level 1

static val HTTP_RESET: Int

HTTP Status-Code 205: Reset Content.

Value: 205

HTTP_SEE_OTHER

Added in API level 1

static val HTTP_SEE_OTHER: Int

HTTP Status-Code 303: See Other.

Value: 303

HTTP_SERVER_ERROR

Added in API level 1
Deprecated in API level 15

static val HTTP_SERVER_ERROR: Int

Deprecated: it is misplaced and shouldn't have existed.

HTTP Status-Code 500: Internal Server Error.

Value: 500

HTTP_UNAUTHORIZED

Added in API level 1

static val HTTP_UNAUTHORIZED: Int

HTTP Status-Code 401: Unauthorized.

Value: 401

HTTP_UNAVAILABLE

Added in API level 1

static val HTTP_UNAVAILABLE: Int

HTTP Status-Code 503: Service Unavailable.

Value: 503

HTTP_UNSUPPORTED_TYPE

Added in API level 1

static val HTTP_UNSUPPORTED_TYPE: Int

HTTP Status-Code 415: Unsupported Media Type.

Value: 415

HTTP_USE_PROXY

Added in API level 1

static val HTTP_USE_PROXY: Int

HTTP Status-Code 305: Use Proxy.

Value: 305

HTTP_VERSION

Added in API level 1

static val HTTP_VERSION: Int

HTTP Status-Code 505: HTTP Version Not Supported.

Value: 505

Protected constructors

HttpURLConnection

Added in API level 1

protected HttpURLConnection(u: URL!)

Constructor for the HttpURLConnection.

Parameters
`u`	URL!: the URL

Public methods

disconnect

Added in API level 1

abstract fun disconnect(): Unit

Indicates that other requests to the server are unlikely in the near future. Calling disconnect() should not imply that this HttpURLConnection instance can be reused for other requests.

getErrorStream

Added in API level 1

open fun getErrorStream(): InputStream!

Returns the error stream if the connection failed but the server sent useful data nonetheless. The typical example is when an HTTP server responds with a 404, which will cause a FileNotFoundException to be thrown in connect, but the server sent an HTML help page with suggestions as to what to do.

This method will not cause a connection to be initiated. If the connection was not connected, or if the server did not have an error while connecting or if the server had an error but no error data was sent, this method will return null. This is the default.

Return
`InputStream!`	an error stream if any, null if there have been no errors, the connection is not connected or the server sent no useful data.

getFollowRedirects

Added in API level 1

open static fun getFollowRedirects(): Boolean

Returns a boolean indicating whether or not HTTP redirects (3xx) should be automatically followed.

Return
`Boolean`	`true` if HTTP redirects should be automatically followed, `false` if not.

See Also

#setFollowRedirects(boolean)

getHeaderField

Added in API level 1

open fun getHeaderField(n: Int): String!

Returns the value for the nth header field. Some implementations may treat the 0th header field as special, i.e. as the status line returned by the HTTP server.

This method can be used in conjunction with the getHeaderFieldKey method to iterate through all the headers in the message.

Parameters
`n`	Int: an index, where `n>=0`.

Return
`String!`	the value of the `n`th header field, or `null` if the value does not exist.

See Also

java.net.HttpURLConnection#getHeaderFieldKey(int)

getHeaderFieldDate

Added in API level 1

open fun getHeaderFieldDate(
    name: String!, 
    Default: Long
): Long

Parameters
`name`	String!: the name of the header field.
`Default`	Long: a default value.

Return
`Long`	the value of the field, parsed as a date. The value of the `Default` argument is returned if the field is missing or malformed.

getHeaderFieldKey

Added in API level 1

open fun getHeaderFieldKey(n: Int): String!

Returns the key for the nth header field. Some implementations may treat the 0th header field as special, i.e. as the status line returned by the HTTP server. In this case, getHeaderField(0) returns the status line, but getHeaderFieldKey(0) returns null.

Parameters
`n`	Int: an index, where `n >=0`.

Return
`String!`	the key for the `n`th header field, or `null` if the key does not exist.

getInstanceFollowRedirects

Added in API level 1

open fun getInstanceFollowRedirects(): Boolean

Returns the value of this HttpURLConnection's instanceFollowRedirects field.

Return
`Boolean`	the value of this `HttpURLConnection`'s `instanceFollowRedirects` field.

See Also

java.net.HttpURLConnection#instanceFollowRedirects
#setInstanceFollowRedirects(boolean)

getPermission

Added in API level 1

open fun getPermission(): Permission!

Returns a SocketPermission object representing the permission necessary to connect to the destination host and port.

Return
`Permission!`	a `SocketPermission` object representing the permission necessary to connect to the destination host and port.

Exceptions
`java.io.IOException`	if an error occurs while computing the permission.

getRequestMethod

Added in API level 1

open fun getRequestMethod(): String!

Get the request method.

Return
`String!`	the HTTP request method

See Also

#setRequestMethod(java.lang.String)

getResponseCode

Added in API level 1

open fun getResponseCode(): Int

Gets the status code from an HTTP response message. For example, in the case of the following status lines:

HTTP/1.0 200 OK
  HTTP/1.0 401 Unauthorized

It will return 200 and 401 respectively. Returns -1 if no code can be discerned from the response (i.e., the response is not valid HTTP).

Return
`Int`	the HTTP Status-Code, or -1

Exceptions
`java.io.IOException`	if an error occurred connecting to the server.

getResponseMessage

Added in API level 1

open fun getResponseMessage(): String!

Gets the HTTP response message, if any, returned along with the response code from a server. From responses like:

HTTP/1.0 200 OK
  HTTP/1.0 404 Not Found

Extracts the Strings "OK" and "Not Found" respectively. Returns null if none could be discerned from the responses (the result was not valid HTTP).

Return
`String!`	the HTTP response message, or `null`

Exceptions
`java.io.IOException`	if an error occurred connecting to the server.

setChunkedStreamingMode

Added in API level 1

open fun setChunkedStreamingMode(chunklen: Int): Unit

This method is used to enable streaming of a HTTP request body without internal buffering, when the content length is not known in advance. In this mode, chunked transfer encoding is used to send the request body. Note, not all HTTP servers support this mode.

When output streaming is enabled, authentication and redirection cannot be handled automatically. A HttpRetryException will be thrown when reading the response if authentication or redirection are required. This exception can be queried for the details of the error.

This method must be called before the URLConnection is connected.

Parameters
`chunklen`	Int: The number of bytes to write in each chunk. If chunklen is less than or equal to zero, a default value will be used.

Exceptions
`java.lang.IllegalStateException`	if URLConnection is already connected or if a different streaming mode is already enabled.

See Also

#setFixedLengthStreamingMode(int)

setFixedLengthStreamingMode

Added in API level 1

open fun setFixedLengthStreamingMode(contentLength: Int): Unit

This method is used to enable streaming of a HTTP request body without internal buffering, when the content length is known in advance.

An exception will be thrown if the application attempts to write more data than the indicated content-length, or if the application closes the OutputStream before writing the indicated amount.

This method must be called before the URLConnection is connected.

NOTE: setFixedLengthStreamingMode(long) is recommended instead of this method as it allows larger content lengths to be set.

Parameters
`contentLength`	Int: The number of bytes which will be written to the OutputStream.

Exceptions
`java.lang.IllegalStateException`	if URLConnection is already connected or if a different streaming mode is already enabled.
`java.lang.IllegalArgumentException`	if a content length less than zero is specified.

See Also

#setChunkedStreamingMode(int)

setFixedLengthStreamingMode

Added in API level 19

open fun setFixedLengthStreamingMode(contentLength: Long): Unit

This method is used to enable streaming of a HTTP request body without internal buffering, when the content length is known in advance.

An exception will be thrown if the application attempts to write more data than the indicated content-length, or if the application closes the OutputStream before writing the indicated amount.

This method must be called before the URLConnection is connected.

The content length set by invoking this method takes precedence over any value set by setFixedLengthStreamingMode(int).

Parameters
`contentLength`	Long: The number of bytes which will be written to the OutputStream.

Exceptions
`java.lang.IllegalStateException`	if URLConnection is already connected or if a different streaming mode is already enabled.
`java.lang.IllegalArgumentException`	if a content length less than zero is specified.

setFollowRedirects

Added in API level 1

open static fun setFollowRedirects(set: Boolean): Unit

Sets whether HTTP redirects (requests with response code 3xx) should be automatically followed by this class. True by default. Applets cannot change this variable.

If there is a security manager, this method first calls the security manager's checkSetFactory method to ensure the operation is allowed. This could result in a SecurityException.

Parameters
`set`	Boolean: a `boolean` indicating whether or not to follow HTTP redirects.

Exceptions
`java.lang.SecurityException`	if a security manager exists and its `checkSetFactory` method doesn't allow the operation.

See Also

setInstanceFollowRedirects

Added in API level 1

open fun setInstanceFollowRedirects(followRedirects: Boolean): Unit

Sets whether HTTP redirects (requests with response code 3xx) should be automatically followed by this HttpURLConnection instance.

The default value comes from followRedirects, which defaults to true.

Parameters
`followRedirects`	Boolean: a `boolean` indicating whether or not to follow HTTP redirects.

See Also

java.net.HttpURLConnection#instanceFollowRedirects
#getInstanceFollowRedirects

setRequestMethod

Added in API level 1

open fun setRequestMethod(method: String!): Unit

Set the method for the URL request, one of:

GET
POST
HEAD
OPTIONS
PUT
DELETE
TRACE

are legal, subject to protocol restrictions. The default method is GET.

Parameters
`method`	String!: the HTTP method

Exceptions
`java.net.ProtocolException`	if the method cannot be reset or if the requested method isn't valid for HTTP.
`java.lang.SecurityException`	if a security manager is set and the method is "TRACE", but the "allowHttpTrace" NetPermission is not granted.

See Also

#getRequestMethod()

usingProxy

Added in API level 1

abstract fun usingProxy(): Boolean

Indicates if the connection is going through a proxy.

Return
`Boolean`	a boolean indicating if the connection is using a proxy.

Properties

chunkLength

Added in API level 1

protected var chunkLength: Int

The chunk-length when using chunked encoding streaming mode for output. A value of -1 means chunked encoding is disabled for output.

fixedContentLength

Added in API level 1

protected var fixedContentLength: Int

The fixed content-length when using fixed-length streaming mode. A value of -1 means fixed-length streaming mode is disabled for output.

NOTE: fixedContentLengthLong is recommended instead of this field, as it allows larger content lengths to be set.

fixedContentLengthLong

Added in API level 19

protected var fixedContentLengthLong: Long

The fixed content-length when using fixed-length streaming mode. A value of -1 means fixed-length streaming mode is disabled for output.

instanceFollowRedirects

Added in API level 1

protected var instanceFollowRedirects: Boolean

If true, the protocol will automatically follow redirects. If false, the protocol will not automatically follow redirects.

This field is set by the setInstanceFollowRedirects method. Its value is returned by the getInstanceFollowRedirects method.

Its default value is based on the value of the static followRedirects at HttpURLConnection construction time.

See Also

java.net.HttpURLConnection#setInstanceFollowRedirects(boolean)
java.net.HttpURLConnection#getInstanceFollowRedirects()
java.net.HttpURLConnection#setFollowRedirects(boolean)

method

Added in API level 1

protected var method: String!

The HTTP method (GET,POST,PUT,etc.).

responseCode

Added in API level 1

protected var responseCode: Int

An int representing the three digit HTTP Status-Code.

1xx: Informational
2xx: Success
3xx: Redirection
4xx: Client Error
5xx: Server Error

responseMessage

Added in API level 1

protected var responseMessage: String!

The HTTP response message.