Package Summary Overview Summary

### class:HttpURLConnection [NONE]
Direct Known Subclasses: `HttpsURLConnection` public abstract class HttpURLConnection extends URLConnection A URLConnection with support for HTTP-specific features. See the spec for details. Each HttpURLConnection instance is used to make a single request but the underlying network connection to the HTTP server may be transparently shared by other instances. Calling the close() methods on the InputStream or OutputStream of an HttpURLConnection after a request may free network resources associated with this instance but has no effect on any shared persistent connection. Calling the disconnect() method may close the underlying socket if a persistent connection is otherwise idle at that time. The HTTP protocol handler has a few settings that can be accessed through System Properties. This covers Proxy settings as well as various other settings . Security permissions If a security manager is installed, and if a method is called which results in an attempt to open a connection, the caller must possess either: a "connect" `SocketPermission` to the host/port combination of the destination URL or a `URLPermission` that permits this request. If automatic redirection is enabled, and this request is redirected to another destination, then the caller must also have permission to connect to the redirected host/URL. Since: 1.1 See Also: `disconnect()`

### field:method [NONE]
### method protected String method The HTTP method (GET,POST,PUT,etc.).

### field:chunkLength [NONE]
### chunkLength protected int chunkLength The chunk-length when using chunked encoding streaming mode for output. A value of `-1` means chunked encoding is disabled for output. Since: 1.5

### field:fixedContentLength [NONE]
### fixedContentLength protected int fixedContentLength 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. Since: 1.5

### field:fixedContentLengthLong [NONE]
### fixedContentLengthLong protected long fixedContentLengthLong The fixed content-length when using fixed-length streaming mode. A value of `-1` means fixed-length streaming mode is disabled for output. Since: 1.7

### field:responseCode [NONE]
### responseCode protected int responseCode An `int` representing the three digit HTTP Status-Code. 1xx: Informational 2xx: Success 3xx: Redirection 4xx: Client Error 5xx: Server Error

### field:responseMessage [NONE]
### responseMessage protected String responseMessage The HTTP response message.

### field:instanceFollowRedirects [NONE]
### instanceFollowRedirects protected boolean instanceFollowRedirects 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: `setInstanceFollowRedirects(boolean)` `getInstanceFollowRedirects()` `setFollowRedirects(boolean)`

### field:HTTP_OK [NONE]
### HTTP_OK public static final int HTTP_OK HTTP Status-Code 200: OK. See Also: Constant Field Values

### field:HTTP_CREATED [NONE]
### HTTP_CREATED public static final int HTTP_CREATED HTTP Status-Code 201: Created. See Also: Constant Field Values

### field:HTTP_ACCEPTED [NONE]
### HTTP_ACCEPTED public static final int HTTP_ACCEPTED HTTP Status-Code 202: Accepted. See Also: Constant Field Values

### field:HTTP_NOT_AUTHORITATIVE [NONE]
### HTTP_NOT_AUTHORITATIVE public static final int HTTP_NOT_AUTHORITATIVE HTTP Status-Code 203: Non-Authoritative Information. See Also: Constant Field Values

### field:HTTP_NO_CONTENT [NONE]
### HTTP_NO_CONTENT public static final int HTTP_NO_CONTENT HTTP Status-Code 204: No Content. See Also: Constant Field Values

### field:HTTP_RESET [NONE]
### HTTP_RESET public static final int HTTP_RESET HTTP Status-Code 205: Reset Content. See Also: Constant Field Values

### field:HTTP_PARTIAL [NONE]
### HTTP_PARTIAL public static final int HTTP_PARTIAL HTTP Status-Code 206: Partial Content. See Also: Constant Field Values

### field:HTTP_MULT_CHOICE [NONE]
### HTTP_MULT_CHOICE public static final int HTTP_MULT_CHOICE HTTP Status-Code 300: Multiple Choices. See Also: Constant Field Values

### field:HTTP_MOVED_PERM [NONE]
### HTTP_MOVED_PERM public static final int HTTP_MOVED_PERM HTTP Status-Code 301: Moved Permanently. See Also: Constant Field Values

### field:HTTP_MOVED_TEMP [NONE]
### HTTP_MOVED_TEMP public static final int HTTP_MOVED_TEMP HTTP Status-Code 302: Temporary Redirect. See Also: Constant Field Values

### field:HTTP_SEE_OTHER [NONE]
### HTTP_SEE_OTHER public static final int HTTP_SEE_OTHER HTTP Status-Code 303: See Other. See Also: Constant Field Values

### field:HTTP_NOT_MODIFIED [NONE]
### HTTP_NOT_MODIFIED public static final int HTTP_NOT_MODIFIED HTTP Status-Code 304: Not Modified. See Also: Constant Field Values

### field:HTTP_USE_PROXY [NONE]
### HTTP_USE_PROXY public static final int HTTP_USE_PROXY HTTP Status-Code 305: Use Proxy. See Also: Constant Field Values

### field:HTTP_BAD_REQUEST [NONE]
### HTTP_BAD_REQUEST public static final int HTTP_BAD_REQUEST HTTP Status-Code 400: Bad Request. See Also: Constant Field Values

### field:HTTP_UNAUTHORIZED [NONE]
### HTTP_UNAUTHORIZED public static final int HTTP_UNAUTHORIZED HTTP Status-Code 401: Unauthorized. See Also: Constant Field Values

### field:HTTP_PAYMENT_REQUIRED [NONE]
### HTTP_PAYMENT_REQUIRED public static final int HTTP_PAYMENT_REQUIRED HTTP Status-Code 402: Payment Required. See Also: Constant Field Values

### field:HTTP_FORBIDDEN [NONE]
### HTTP_FORBIDDEN public static final int HTTP_FORBIDDEN HTTP Status-Code 403: Forbidden. See Also: Constant Field Values

### field:HTTP_NOT_FOUND [NONE]
### HTTP_NOT_FOUND public static final int HTTP_NOT_FOUND HTTP Status-Code 404: Not Found. See Also: Constant Field Values

### field:HTTP_BAD_METHOD [NONE]
### HTTP_BAD_METHOD public static final int HTTP_BAD_METHOD HTTP Status-Code 405: Method Not Allowed. See Also: Constant Field Values

### field:HTTP_NOT_ACCEPTABLE [NONE]
### HTTP_NOT_ACCEPTABLE public static final int HTTP_NOT_ACCEPTABLE HTTP Status-Code 406: Not Acceptable. See Also: Constant Field Values

### field:HTTP_PROXY_AUTH [NONE]
### HTTP_PROXY_AUTH public static final int HTTP_PROXY_AUTH HTTP Status-Code 407: Proxy Authentication Required. See Also: Constant Field Values

### field:HTTP_CLIENT_TIMEOUT [NONE]
### HTTP_CLIENT_TIMEOUT public static final int HTTP_CLIENT_TIMEOUT HTTP Status-Code 408: Request Time-Out. See Also: Constant Field Values

### field:HTTP_CONFLICT [NONE]
### HTTP_CONFLICT public static final int HTTP_CONFLICT HTTP Status-Code 409: Conflict. See Also: Constant Field Values

### field:HTTP_GONE [NONE]
### HTTP_GONE public static final int HTTP_GONE HTTP Status-Code 410: Gone. See Also: Constant Field Values

### field:HTTP_LENGTH_REQUIRED [NONE]
### HTTP_LENGTH_REQUIRED public static final int HTTP_LENGTH_REQUIRED HTTP Status-Code 411: Length Required. See Also: Constant Field Values

### field:HTTP_PRECON_FAILED [NONE]
### HTTP_PRECON_FAILED public static final int HTTP_PRECON_FAILED HTTP Status-Code 412: Precondition Failed. See Also: Constant Field Values

### field:HTTP_ENTITY_TOO_LARGE [NONE]
### HTTP_ENTITY_TOO_LARGE public static final int HTTP_ENTITY_TOO_LARGE HTTP Status-Code 413: Request Entity Too Large. See Also: Constant Field Values

### field:HTTP_REQ_TOO_LONG [NONE]
### HTTP_REQ_TOO_LONG public static final int HTTP_REQ_TOO_LONG HTTP Status-Code 414: Request-URI Too Large. See Also: Constant Field Values

### field:HTTP_UNSUPPORTED_TYPE [NONE]
### HTTP_UNSUPPORTED_TYPE public static final int HTTP_UNSUPPORTED_TYPE HTTP Status-Code 415: Unsupported Media Type. See Also: Constant Field Values

### field:HTTP_SERVER_ERROR [NONE]
### HTTP_SERVER_ERROR @Deprecated public static final int HTTP_SERVER_ERROR Deprecated. it is misplaced and shouldn't have existed. HTTP Status-Code 500: Internal Server Error. See Also: Constant Field Values

### field:HTTP_INTERNAL_ERROR [NONE]
### HTTP_INTERNAL_ERROR public static final int HTTP_INTERNAL_ERROR HTTP Status-Code 500: Internal Server Error. See Also: Constant Field Values

### field:HTTP_NOT_IMPLEMENTED [NONE]
### HTTP_NOT_IMPLEMENTED public static final int HTTP_NOT_IMPLEMENTED HTTP Status-Code 501: Not Implemented. See Also: Constant Field Values

### field:HTTP_BAD_GATEWAY [NONE]
### HTTP_BAD_GATEWAY public static final int HTTP_BAD_GATEWAY HTTP Status-Code 502: Bad Gateway. See Also: Constant Field Values

### field:HTTP_UNAVAILABLE [NONE]
### HTTP_UNAVAILABLE public static final int HTTP_UNAVAILABLE HTTP Status-Code 503: Service Unavailable. See Also: Constant Field Values

### field:HTTP_GATEWAY_TIMEOUT [NONE]
### HTTP_GATEWAY_TIMEOUT public static final int HTTP_GATEWAY_TIMEOUT HTTP Status-Code 504: Gateway Timeout. See Also: Constant Field Values

### field:HTTP_VERSION [NONE]
### HTTP_VERSION public static final int HTTP_VERSION HTTP Status-Code 505: HTTP Version Not Supported. See Also: Constant Field Values

### constructor:HttpURLConnection(java.net.URL) [NONE]
### HttpURLConnection protected HttpURLConnection (URL u) Constructor for the HttpURLConnection. Parameters: `u` - the URL

### method:setAuthenticator(java.net.Authenticator) [NONE]
### setAuthenticator public void setAuthenticator (Authenticator auth) Supplies an `Authenticator` to be used when authentication is requested through the HTTP protocol for this `HttpURLConnection`. If no authenticator is supplied, the default authenticator will be used. Implementation Requirements: The default behavior of this method is to unconditionally throw `UnsupportedOperationException`. Concrete implementations of `HttpURLConnection` which support supplying an `Authenticator` for a specific `HttpURLConnection` instance should override this method to implement a different behavior. Implementation Note: Depending on authentication schemes, an implementation may or may not need to use the provided authenticator to obtain a password. For instance, an implementation that relies on third-party security libraries may still invoke the default authenticator if these libraries are configured to do so. Likewise, an implementation that supports transparent NTLM authentication may let the system attempt to connect using the system user credentials first, before invoking the provided authenticator. However, if an authenticator is specifically provided, then the underlying connection may only be reused for `HttpURLConnection` instances which share the same `Authenticator` instance, and authentication information, if cached, may only be reused for an `HttpURLConnection` sharing that same `Authenticator`. Parameters: `auth` - The `Authenticator` that should be used by this `HttpURLConnection`. Throws: `UnsupportedOperationException` - if setting an Authenticator is not supported by the underlying implementation. `IllegalStateException` - if URLConnection is already connected. `NullPointerException` - if the supplied `auth` is `null`. Since: 9

### method:getHeaderFieldKey(int) [NONE]
### getHeaderFieldKey public String getHeaderFieldKey (int n) Returns the key for the `n`th header field. Some implementations may treat the `0`th 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. Overrides: `getHeaderFieldKey` in class `URLConnection` Parameters: `n` - an index, where `n >=0` . Returns: the key for the `n`th header field, or `null` if the key does not exist.

### method:setFixedLengthStreamingMode(int) [NONE]
### setFixedLengthStreamingMode public void setFixedLengthStreamingMode (int contentLength) 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. 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. NOTE:`setFixedLengthStreamingMode(long)` is recommended instead of this method as it allows larger content lengths to be set. Parameters: `contentLength` - The number of bytes which will be written to the OutputStream. Throws: `IllegalStateException` - if URLConnection is already connected or if a different streaming mode is already enabled. `IllegalArgumentException` - if a content length less than zero is specified. Since: 1.5 See Also: `setChunkedStreamingMode(int)`

### method:setFixedLengthStreamingMode(long) [NONE]
### setFixedLengthStreamingMode public void setFixedLengthStreamingMode (long contentLength) 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. 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. The content length set by invoking this method takes precedence over any value set by `setFixedLengthStreamingMode(int)`. Parameters: `contentLength` - The number of bytes which will be written to the OutputStream. Throws: `IllegalStateException` - if URLConnection is already connected or if a different streaming mode is already enabled. `IllegalArgumentException` - if a content length less than zero is specified. Since: 1.7

### method:setChunkedStreamingMode(int) [NONE]
### setChunkedStreamingMode public void setChunkedStreamingMode (int chunklen) 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` - The number of bytes to write in each chunk. If chunklen is less than or equal to zero, a default value will be used. Throws: `IllegalStateException` - if URLConnection is already connected or if a different streaming mode is already enabled. Since: 1.5 See Also: `setFixedLengthStreamingMode(int)`

### method:getHeaderField(int) [NONE]
### getHeaderField public String getHeaderField (int n) Returns the value for the `n`th header field. Some implementations may treat the `0`th 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. Overrides: `getHeaderField` in class `URLConnection` Parameters: `n` - an index, where `n>=0`. Returns: the value of the `n`th header field, or `null` if the value does not exist. See Also: `getHeaderFieldKey(int)`

### method:setFollowRedirects(boolean) [NONE]
### setFollowRedirects public static void setFollowRedirects (boolean set) 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` - a `boolean` indicating whether or not to follow HTTP redirects. Throws: `SecurityException` - if a security manager exists and its `checkSetFactory` method doesn't allow the operation. See Also: `SecurityManager.checkSetFactory()` `getFollowRedirects()`

### method:getFollowRedirects() [NONE]
### getFollowRedirects public static boolean getFollowRedirects() Returns a `boolean` indicating whether or not HTTP redirects (3xx) should be automatically followed. Returns: `true` if HTTP redirects should be automatically followed, `false` if not. See Also: `setFollowRedirects(boolean)`

### method:setInstanceFollowRedirects(boolean) [NONE]
### setInstanceFollowRedirects public void setInstanceFollowRedirects (boolean followRedirects) 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` - a `boolean` indicating whether or not to follow HTTP redirects. Since: 1.3 See Also: `instanceFollowRedirects` `getInstanceFollowRedirects()`

### method:getInstanceFollowRedirects() [NONE]
### getInstanceFollowRedirects public boolean getInstanceFollowRedirects() Returns the value of this `HttpURLConnection`'s `instanceFollowRedirects` field. Returns: the value of this `HttpURLConnection`'s `instanceFollowRedirects` field. Since: 1.3 See Also: `instanceFollowRedirects` `setInstanceFollowRedirects(boolean)`

### method:setRequestMethod(java.lang.String) [NONE]
### setRequestMethod public void setRequestMethod (String method) throws ProtocolException 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` - the HTTP method Throws: `ProtocolException` - if the method cannot be reset or if the requested method isn't valid for HTTP. `SecurityException` - if a security manager is set and the method is "TRACE", but the "allowHttpTrace" NetPermission is not granted. See Also: `getRequestMethod()`

### method:getRequestMethod() [NONE]
### getRequestMethod public String getRequestMethod() Get the request method. Returns: the HTTP request method See Also: `setRequestMethod(java.lang.String)`

### method:getResponseCode() [NONE]
### getResponseCode public int getResponseCode() throws IOException 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). Returns: the HTTP Status-Code, or -1 Throws: `IOException` - if an error occurred connecting to the server.

### method:getResponseMessage() [NONE]
### getResponseMessage public String getResponseMessage() throws IOException 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). Returns: the HTTP response message, or `null` Throws: `IOException` - if an error occurred connecting to the server.

### method:disconnect() [NONE]
### disconnect public abstract void disconnect() 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.

### method:usingProxy() [NONE]
### usingProxy public abstract boolean usingProxy() Indicates if the connection is going through a proxy. This method returns `true` if the connection is known to be going or has gone through proxies, and returns `false` if the connection will never go through a proxy or if the use of a proxy cannot be determined. Returns: a boolean indicating if the connection is using a proxy.

### method:getPermission() [NONE]
### getPermission public Permission getPermission() throws IOException Returns a `SocketPermission` object representing the permission necessary to connect to the destination host and port. Overrides: `getPermission` in class `URLConnection` Returns: a `SocketPermission` object representing the permission necessary to connect to the destination host and port. Throws: `IOException` - if an error occurs while computing the permission.

### method:getErrorStream() [NONE]
### getErrorStream public InputStream getErrorStream() 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. Returns: an error stream if any, null if there have been no errors, the connection is not connected or the server sent no useful data.