URLConnection
abstract class URLConnection
kotlin.Any | |
↳ | java.net.URLConnection |
The abstract class is the superclass of all classes that represent a communications link between the application and a URL. Instances of this class can be used both to read from and to write to the resource referenced by the URL. In general, creating a connection to a URL is a multistep process:
openConnection() |
connect() |
---|---|
Manipulate parameters that affect the connection to the remote resource. | Interact with the resource; query header fields and contents. |
time
- The connection object is created by invoking the
openConnection
method on a URL. - The setup parameters and general request properties are manipulated.
- The actual connection to the remote object is made, using the
connect
method. - The remote object becomes available. The header fields and the contents of the remote object can be accessed.
The setup parameters are modified using the following methods:
setAllowUserInteraction
setDoInput
setDoOutput
setIfModifiedSince
setUseCaches
and the general request properties are modified using the method:
setRequestProperty
Default values for the AllowUserInteraction
and UseCaches
parameters can be set using the methods setDefaultAllowUserInteraction
and setDefaultUseCaches
.
Each of the above set
methods has a corresponding get
method to retrieve the value of the parameter or general request property. The specific parameters and general request properties that are applicable are protocol specific.
The following methods are used to access the header fields and the contents after the connection is made to the remote object:
getContent
getHeaderField
getInputStream
getOutputStream
Certain header fields are accessed frequently. The methods:
getContentEncoding
getContentLength
getContentType
getDate
getExpiration
getLastModifed
provide convenient access to these fields. The getContentType
method is used by the getContent
method to determine the type of the remote object; subclasses may find it convenient to override the getContentType
method.
In the common case, all of the pre-connection parameters and general request properties can be ignored: the pre-connection parameters and request properties default to sensible values. For most clients of this interface, there are only two interesting methods: getInputStream
and getContent
, which are mirrored in the URL
class by convenience methods.
More information on the request properties and header fields of an http
connection can be found at:
<a href="http://www.ietf.org/rfc/rfc2616.txt">http://www.ietf.org/rfc/rfc2616.txt</a>
close()
methods on the InputStream
or OutputStream
of an URLConnection
after a request may free network resources associated with this instance, unless particular protocol specifications specify different behaviours for it.
Summary
Protected constructors | |
---|---|
URLConnection(url: URL!) Constructs a URL connection to the specified URL. |
Public methods | |
---|---|
open Unit |
addRequestProperty(key: String!, value: String!) Adds a general request property specified by a key-value pair. |
abstract Unit |
connect() Opens a communications link to the resource referenced by this URL, if such a connection has not already been established. |
open Boolean |
Returns the value of the |
open Int |
Returns setting for connect timeout. |
open Any! |
Retrieves the contents of this URL connection. |
open Any! |
getContent(classes: Array<Class<Any!>!>!) Retrieves the contents of this URL connection. |
open String! |
Returns the value of the |
open Int |
Returns the value of the |
open Long |
Returns the value of the |
open String! |
Returns the value of the |
open Long |
getDate() Returns the value of the |
open static Boolean |
Returns the default value of the |
open static String! |
getDefaultRequestProperty(key: String!) Returns the value of the default request property. |
open Boolean |
Returns the default value of a |
open Boolean |
Returns the value of this |
open Boolean |
Returns the value of this |
open Long |
Returns the value of the |
open static FileNameMap! |
Returns a |
open String! |
getHeaderField(n: Int) Returns the value for the |
open String! |
getHeaderField(name: String!) Returns the value of the named header field. |
open Long |
getHeaderFieldDate(name: String!, Default: Long) Returns the value of the named field parsed as date. |
open Int |
getHeaderFieldInt(name: String!, Default: Int) Returns the value of the named field parsed as a number. |
open String! |
getHeaderFieldKey(n: Int) Returns the key for the |
open Long |
getHeaderFieldLong(name: String!, Default: Long) Returns the value of the named field parsed as a number. |
open MutableMap<String!, MutableList<String!>!>! |
Returns an unmodifiable Map of the header fields. |
open Long |
Returns the value of this object's |
open InputStream! |
Returns an input stream that reads from this open connection. |
open Long |
Returns the value of the |
open OutputStream! |
Returns an output stream that writes to this connection. |
open Permission! |
Returns a permission object representing the permission necessary to make the connection represented by this object. |
open Int |
Returns setting for read timeout. |
open MutableMap<String!, MutableList<String!>!>! |
Returns an unmodifiable Map of general request properties for this connection. |
open String! |
getRequestProperty(key: String!) Returns the value of the named general request property for this connection. |
open URL! |
getURL() Returns the value of this |
open Boolean |
Returns the value of this |
open static String! |
guessContentTypeFromName(fname: String!) Tries to determine the content type of an object, based on the specified "file" component of a URL. |
open static String! |
Tries to determine the type of an input stream based on the characters at the beginning of the input stream. |
open Unit |
setAllowUserInteraction(allowuserinteraction: Boolean) Set the value of the |
open 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. |
open static Unit |
Sets the |
open static Unit |
setDefaultAllowUserInteraction(defaultallowuserinteraction: Boolean) Sets the default value of the |
open static Unit |
setDefaultRequestProperty(key: String!, value: String!) Sets the default value of a general request property. |
open Unit |
setDefaultUseCaches(defaultusecaches: Boolean) Sets the default value of the |
open Unit |
setDoInput(doinput: Boolean) Sets the value of the |
open Unit |
setDoOutput(dooutput: Boolean) Sets the value of the |
open static Unit |
setFileNameMap(map: FileNameMap!) Sets the FileNameMap. |
open Unit |
setIfModifiedSince(ifmodifiedsince: Long) Sets the value of the |
open Unit |
setReadTimeout(timeout: Int) Sets the read timeout to a specified timeout, in milliseconds. |
open Unit |
setRequestProperty(key: String!, value: String!) Sets the general request property. |
open Unit |
setUseCaches(usecaches: Boolean) Sets the value of the |
open String |
toString() Returns a |
Properties | |
---|---|
Boolean |
If |
Boolean |
If |
Boolean |
This variable is set by the |
Boolean |
This variable is set by the |
Long |
Some protocols support skipping the fetching of the object unless the object has been modified more recently than a certain time. |
URL! |
The URL represents the remote object on the World Wide Web to which this connection is opened. |
Boolean |
If |
Protected constructors
URLConnection
protected URLConnection(url: URL!)
Constructs a URL connection to the specified URL. A connection to the object referenced by the URL is not created.
Parameters | |
---|---|
url |
URL!: the specified URL. |
Public methods
addRequestProperty
open fun addRequestProperty(
key: String!,
value: String!
): Unit
Adds a general request property specified by a key-value pair. This method will not overwrite existing values associated with the same key.
Parameters | |
---|---|
key |
String!: the keyword by which the request is known (e.g., "Accept "). |
value |
String!: the value associated with it. |
Exceptions | |
---|---|
java.lang.IllegalStateException |
if already connected |
java.lang.NullPointerException |
if key is null |
See Also
connect
abstract fun connect(): Unit
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.
Exceptions | |
---|---|
java.net.SocketTimeoutException |
if the timeout expires before the connection can be established |
java.io.IOException |
if an I/O error occurs while opening the connection. |
getAllowUserInteraction
open fun getAllowUserInteraction(): Boolean
Returns the value of the allowUserInteraction
field for this object.
Return | |
---|---|
Boolean |
the value of the allowUserInteraction field for this object. |
See Also
getConnectTimeout
open fun getConnectTimeout(): Int
Returns setting for connect timeout.
0 return implies that the option is disabled (i.e., timeout of infinity).
Return | |
---|---|
Int |
an int that indicates the connect timeout value in milliseconds |
See Also
getContent
open fun getContent(): Any!
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, thecreateContentHandler
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 returnsnull
, then the application loads the class named: where <contentType> is formed by taking the content-type string, replacing all slash characters with asun.net.www.content.<<i>contentType</i>>
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 ofContentHandler
, then anUnknownServiceException
is thrown.
Return | |
---|---|
Any! |
the object fetched. The instanceof operator should be used to determine the specific kind of object returned. |
Exceptions | |
---|---|
java.io.IOException |
if an I/O error occurs while getting the content. |
java.net.UnknownServiceException |
if the protocol does not support the content type. |
getContent
open fun getContent(classes: Array<Class<Any!>!>!): Any!
Retrieves the contents of this URL connection.
Parameters | |
---|---|
classes |
Array<Class<Any!>!>!: the Class array indicating the requested types |
Return | |
---|---|
Any! |
the object fetched that is the first match of the type specified in the classes array. null if none of the requested types are supported. The instanceof operator should be used to determine the specific kind of object returned. |
Exceptions | |
---|---|
java.io.IOException |
if an I/O error occurs while getting the content. |
java.net.UnknownServiceException |
if the protocol does not support the content type. |
getContentEncoding
open fun getContentEncoding(): String!
Returns the value of the content-encoding
header field.
Return | |
---|---|
String! |
the content encoding of the resource that the URL references, or null if not known. |
getContentLength
open fun getContentLength(): Int
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.
Return | |
---|---|
Int |
the content length of the resource that this connection's URL references, -1 if the content length is not known, or if the content length is greater than Integer.MAX_VALUE. |
getContentLengthLong
open fun getContentLengthLong(): Long
Returns the value of the content-length
header field as a long.
Return | |
---|---|
Long |
the content length of the resource that this connection's URL references, or -1 if the content length is not known. |
getContentType
open fun getContentType(): String!
Returns the value of the content-type
header field.
Return | |
---|---|
String! |
the content type of the resource that the URL references, or null if not known. |
getDate
open fun getDate(): Long
Returns the value of the date
header field.
Return | |
---|---|
Long |
the sending date of the resource that the URL references, or 0 if not known. The value returned is the number of milliseconds since January 1, 1970 GMT. |
getDefaultAllowUserInteraction
open static fun getDefaultAllowUserInteraction(): Boolean
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.
Return | |
---|---|
Boolean |
the default value of the allowUserInteraction field. |
getDefaultRequestProperty
open static fungetDefaultRequestProperty(key: String!): String!
Deprecated: The instance specific getRequestProperty method should be used after an appropriate instance of URLConnection is obtained.
Returns the value of the default request property. Default request properties are set for every connection.
Parameters | |
---|---|
key |
String!: the keyword by which the request is known (e.g., "Accept"). |
Return | |
---|---|
String! |
the value of the default request property for the specified key. |
getDefaultUseCaches
open fun getDefaultUseCaches(): Boolean
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.
Return | |
---|---|
Boolean |
the default value of a URLConnection 's useCaches flag. |
See Also
getDoInput
open fun getDoInput(): Boolean
Returns the value of this URLConnection
's doInput
flag.
Return | |
---|---|
Boolean |
the value of this URLConnection 's doInput flag. |
See Also
getDoOutput
open fun getDoOutput(): Boolean
Returns the value of this URLConnection
's doOutput
flag.
Return | |
---|---|
Boolean |
the value of this URLConnection 's doOutput flag. |
See Also
getExpiration
open fun getExpiration(): Long
Returns the value of the expires
header field.
Return | |
---|---|
Long |
the expiration date of the resource that this URL references, or 0 if not known. The value is the number of milliseconds since January 1, 1970 GMT. |
getFileNameMap
open static fun getFileNameMap(): FileNameMap!
Returns a FileNameMap
implementation suitable for guessing a content type based on a URL's "file" component.
getHeaderField
open fun getHeaderField(n: Int): String!
Returns the value for the n
th header field. It returns null
if there are fewer than n+1
fields.
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 there are fewer than n+1 fields |
getHeaderField
open fun getHeaderField(name: String!): 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.
Parameters | |
---|---|
name |
String!: the name of a header field. |
Return | |
---|---|
String! |
the value of the named header field, or null if there is no such field in the header. |
getHeaderFieldDate
open fun getHeaderFieldDate(
name: String!,
Default: Long
): Long
Returns the value of the named field parsed as date. The result is the number of milliseconds since January 1, 1970 GMT represented by the named field.
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.
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. |
getHeaderFieldInt
open fun getHeaderFieldInt(
name: String!,
Default: Int
): 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.
Parameters | |
---|---|
name |
String!: the name of the header field. |
Default |
Int: the default value. |
Return | |
---|---|
Int |
the value of the named field, parsed as an integer. The Default value is returned if the field is missing or malformed. |
getHeaderFieldKey
open fun getHeaderFieldKey(n: Int): String!
Returns the key for the n
th header field. It returns null
if there are fewer than n+1
fields.
Parameters | |
---|---|
n |
Int: an index, where n>=0 |
Return | |
---|---|
String! |
the key for the n th header field, or null if there are fewer than n+1 fields. |
getHeaderFieldLong
open fun getHeaderFieldLong(
name: String!,
Default: Long
): 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.
Parameters | |
---|---|
name |
String!: the name of the header field. |
Default |
Long: the default value. |
Return | |
---|---|
Long |
the value of the named field, parsed as a long. The Default value is returned if the field is missing or malformed. |
getHeaderFields
open fun getHeaderFields(): MutableMap<String!, MutableList<String!>!>!
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.
Return | |
---|---|
MutableMap<String!, MutableList<String!>!>! |
a Map of header fields |
getIfModifiedSince
open fun getIfModifiedSince(): Long
Returns the value of this object's ifModifiedSince
field.
Return | |
---|---|
Long |
the value of this object's ifModifiedSince field. |
See Also
getInputStream
open fun getInputStream(): InputStream!
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.
Return | |
---|---|
InputStream! |
an input stream that reads from this open connection. |
Exceptions | |
---|---|
java.io.IOException |
if an I/O error occurs while creating the input stream. |
java.net.UnknownServiceException |
if the protocol does not support input. |
See Also
getLastModified
open fun getLastModified(): Long
Returns the value of the last-modified
header field. The result is the number of milliseconds since January 1, 1970 GMT.
Return | |
---|---|
Long |
the date the resource referenced by this URLConnection was last modified, or 0 if not known. |
getOutputStream
open fun getOutputStream(): OutputStream!
Returns an output stream that writes to this connection.
Return | |
---|---|
OutputStream! |
an output stream that writes to this connection. |
Exceptions | |
---|---|
java.io.IOException |
if an I/O error occurs while creating the output stream. |
java.net.UnknownServiceException |
if the protocol does not support output. |
getPermission
open fun getPermission(): Permission!
Returns a permission object representing the permission necessary to make the connection represented by this object. This method returns null if no permission is required to make the connection. By default, this method returns java.security.AllPermission
. Subclasses should override this method and return the permission that best represents the permission required to make a a connection to the URL. For example, a URLConnection
representing a file:
URL would return a java.io.FilePermission
object.
The permission returned may dependent upon the state of the connection. For example, the permission before connecting may be different from that after connecting. For example, an HTTP sever, say foo.com, may redirect the connection to a different host, say bar.com. Before connecting the permission returned by the connection will represent the permission needed to connect to foo.com, while the permission returned after connecting will be to bar.com.
Permissions are generally used for two purposes: to protect caches of objects obtained through URLConnections, and to check the right of a recipient to learn about a particular URL. In the first case, the permission should be obtained after the object has been obtained. For example, in an HTTP connection, this will represent the permission to connect to the host from which the data was ultimately fetched. In the second case, the permission should be obtained and tested before connecting.
Return | |
---|---|
Permission! |
the permission object representing the permission necessary to make the connection represented by this URLConnection. |
Exceptions | |
---|---|
java.io.IOException |
if the computation of the permission requires network or file I/O and an exception occurs while computing it. |
getReadTimeout
open fun getReadTimeout(): Int
Returns setting for read timeout. 0 return implies that the option is disabled (i.e., timeout of infinity).
Return | |
---|---|
Int |
an int that indicates the read timeout value in milliseconds |
getRequestProperties
open fun getRequestProperties(): MutableMap<String!, MutableList<String!>!>!
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.
Return | |
---|---|
MutableMap<String!, MutableList<String!>!>! |
a Map of the general request properties for this connection. |
Exceptions | |
---|---|
java.lang.IllegalStateException |
if already connected |
getRequestProperty
open fun getRequestProperty(key: String!): String!
Returns the value of the named general request property for this connection.
Parameters | |
---|---|
key |
String!: the keyword by which the request is known (e.g., "Accept"). |
Return | |
---|---|
String! |
the value of the named general request property for this connection. If key is null, then null is returned. |
Exceptions | |
---|---|
java.lang.IllegalStateException |
if already connected |
getURL
open fun getURL(): URL!
Returns the value of this URLConnection
's URL
field.
Return | |
---|---|
URL! |
the value of this URLConnection 's URL field. |
See Also
getUseCaches
open fun getUseCaches(): Boolean
Returns the value of this URLConnection
's useCaches
field.
Return | |
---|---|
Boolean |
the value of this URLConnection 's useCaches field. |
See Also
guessContentTypeFromName
open static fun guessContentTypeFromName(fname: String!): 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.
Parameters | |
---|---|
fname |
String!: a filename. |
Return | |
---|---|
String! |
a guess as to what the content type of the object is, based upon its file name. |
guessContentTypeFromStream
open static fun guessContentTypeFromStream(is: InputStream!): String!
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.
Parameters | |
---|---|
is |
InputStream!: an input stream that supports marks. |
Return | |
---|---|
String! |
a guess at the content type, or null if none can be determined. |
Exceptions | |
---|---|
java.io.IOException |
if an I/O error occurs while reading the input stream. |
setAllowUserInteraction
open fun setAllowUserInteraction(allowuserinteraction: Boolean): Unit
Set the value of the allowUserInteraction
field of this URLConnection
.
Parameters | |
---|---|
allowuserinteraction |
Boolean: the new value. |
Exceptions | |
---|---|
java.lang.IllegalStateException |
if already connected |
See Also
setConnectTimeout
open fun setConnectTimeout(timeout: Int): Unit
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.
Parameters | |
---|---|
timeout |
Int: an int that specifies the connect timeout value in milliseconds |
Exceptions | |
---|---|
java.lang.IllegalArgumentException |
if the timeout parameter is negative |
See Also
setContentHandlerFactory
open static fun setContentHandlerFactory(fac: ContentHandlerFactory!): Unit
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.
Parameters | |
---|---|
fac |
ContentHandlerFactory!: the desired factory. |
Exceptions | |
---|---|
java.lang.Error |
if the factory has already been defined. |
java.lang.SecurityException |
if a security manager exists and its checkSetFactory method doesn't allow the operation. |
setDefaultAllowUserInteraction
open static fun setDefaultAllowUserInteraction(defaultallowuserinteraction: Boolean): Unit
Sets the default value of the allowUserInteraction
field for all future URLConnection
objects to the specified value.
Parameters | |
---|---|
defaultallowuserinteraction |
Boolean: the new value. |
See Also
setDefaultRequestProperty
open static funsetDefaultRequestProperty(
key: String!,
value: String!
): Unit
Deprecated: The instance specific setRequestProperty method should be used after an appropriate instance of URLConnection is obtained. Invoking this method will have no effect.
Sets the default value of a general request property. When a URLConnection
is created, it is initialized with these properties.
Parameters | |
---|---|
key |
String!: the keyword by which the request is known (e.g., "Accept "). |
value |
String!: the value associated with the key. |
setDefaultUseCaches
open fun setDefaultUseCaches(defaultusecaches: Boolean): Unit
Sets the default value of the useCaches
field to the specified value.
Parameters | |
---|---|
defaultusecaches |
Boolean: the new value. |
See Also
setDoInput
open fun setDoInput(doinput: Boolean): Unit
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.
Parameters | |
---|---|
doinput |
Boolean: the new value. |
Exceptions | |
---|---|
java.lang.IllegalStateException |
if already connected |
setDoOutput
open fun setDoOutput(dooutput: Boolean): Unit
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.
Parameters | |
---|---|
dooutput |
Boolean: the new value. |
Exceptions | |
---|---|
java.lang.IllegalStateException |
if already connected |
See Also
setFileNameMap
open static fun setFileNameMap(map: FileNameMap!): Unit
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.
Parameters | |
---|---|
map |
FileNameMap!: the FileNameMap to be set |
Exceptions | |
---|---|
java.lang.SecurityException |
if a security manager exists and its checkSetFactory method doesn't allow the operation. |
setIfModifiedSince
open fun setIfModifiedSince(ifmodifiedsince: Long): Unit
Sets the value of the ifModifiedSince
field of this URLConnection
to the specified value.
Parameters | |
---|---|
ifmodifiedsince |
Long: the new value. |
Exceptions | |
---|---|
java.lang.IllegalStateException |
if already connected |
See Also
setReadTimeout
open fun setReadTimeout(timeout: Int): Unit
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().
Parameters | |
---|---|
timeout |
Int: an int that specifies the timeout value to be used in milliseconds |
Exceptions | |
---|---|
java.lang.IllegalArgumentException |
if the timeout parameter is negative |
setRequestProperty
open fun setRequestProperty(
key: String!,
value: String!
): Unit
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.
Parameters | |
---|---|
key |
String!: the keyword by which the request is known (e.g., "Accept "). |
value |
String!: the value associated with it. |
Exceptions | |
---|---|
java.lang.IllegalStateException |
if already connected |
java.lang.NullPointerException |
if key is null |
setUseCaches
open fun setUseCaches(usecaches: Boolean): Unit
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.
Parameters | |
---|---|
usecaches |
Boolean: a boolean indicating whether or not to allow caching |
Exceptions | |
---|---|
java.lang.IllegalStateException |
if already connected |
See Also
toString
open fun toString(): String
Returns a String
representation of this URL connection.
Return | |
---|---|
String |
a string representation of this URLConnection . |
Properties
allowUserInteraction
protected var allowUserInteraction: Boolean
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.
connected
protected var connected: Boolean
If false
, this connection object has not created a communications link to the specified URL. If true
, the communications link has been established.
doInput
protected var doInput: Boolean
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
.
doOutput
protected var doOutput: Boolean
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
.
ifModifiedSince
protected var ifModifiedSince: Long
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
protected var 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.
useCaches
protected var useCaches: Boolean
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.