URLConnection Class
Definition
Important
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The abstract class URLConnection
is the superclass
of all classes that represent a communications link between the
application and a URL.
[Android.Runtime.Register("java/net/URLConnection", DoNotGenerateAcw=true)]
public abstract class URLConnection : Java.Lang.Object
[<Android.Runtime.Register("java/net/URLConnection", DoNotGenerateAcw=true)>]
type URLConnection = class
inherit Object
- Inheritance
- Derived
- Attributes
Remarks
The abstract class URLConnection
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:
<center><table border=2 summary="Describes the process of creating a connection to a URL: openConnection() and connect() over time."> <tr><th>openConnection()
</th> <th>connect()
</th></tr> <tr><td>Manipulate parameters that affect the connection to the remote resource.</td> <td>Interact with the resource; query header fields and contents.</td></tr> </table> ----------------------------> <br>time</center>
<ol> <li>The connection object is created by invoking the openConnection
method on a URL. <li>The setup parameters and general request properties are manipulated. <li>The actual connection to the remote object is made, using the connect
method. <li>The remote object becomes available. The header fields and the contents of the remote object can be accessed. </ol>
The setup parameters are modified using the following methods: <ul> <li>setAllowUserInteraction
<li>setDoInput
<li>setDoOutput
<li>setIfModifiedSince
<li>setUseCaches
</ul>
and the general request properties are modified using the method: <ul> <li>setRequestProperty
</ul>
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: <ul> <li>getContent
<li>getHeaderField
<li>getInputStream
<li>getOutputStream
</ul>
Certain header fields are accessed frequently. The methods: <ul> <li>getContentEncoding
<li>getContentLength
<li>getContentType
<li>getDate
<li>getExpiration
<li>getLastModifed
</ul>
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: <blockquote>
<a href="http://www.ietf.org/rfc/rfc2616.txt">http://www.ietf.org/rfc/rfc2616.txt</a>
</blockquote>
Invoking the 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.
Added in JDK1.0.
Java documentation for java.net.URLConnection
.
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.
Constructors
URLConnection(IntPtr, JniHandleOwnership) |
A constructor used when creating managed representations of JNI objects; called by the runtime. |
URLConnection(URL) |
Constructs a URL connection to the specified URL. |
Properties
AllowUserInteraction |
Returns the value of the |
Class |
Returns the runtime class of this |
Connected |
If |
ConnectTimeout |
Returns setting for connect timeout. -or- Sets a specified timeout value, in milliseconds, to be used when opening a communications link to the resource referenced by this URLConnection. |
Content |
Retrieves the contents of this URL connection. |
ContentEncoding |
Returns the value of the |
ContentLength |
Returns the value of the |
ContentLengthLong |
Returns the value of the |
ContentType |
Returns the value of the |
Date |
Returns the value of the |
DefaultAllowUserInteraction |
Returns the default value of the |
DefaultUseCaches |
Returns the default value of a |
DoInput |
Returns the value of this |
DoOutput |
Returns the value of this |
Expiration |
Returns the value of the |
FileNameMap |
Returns a |
Handle |
The handle to the underlying Android instance. (Inherited from Object) |
HeaderFields |
Returns an unmodifiable Map of the header fields. |
IfModifiedSince |
Returns the value of this object's |
InputStream |
Returns an input stream that reads from this open connection. |
JniIdentityHashCode | (Inherited from Object) |
JniPeerMembers | |
LastModified |
Returns the value of the |
OutputStream |
Returns an output stream that writes to this connection. |
PeerReference | (Inherited from Object) |
Permission |
Returns a permission object representing the permission necessary to make the connection represented by this object. |
ReadTimeout |
Returns setting for read timeout. -or- Sets the read timeout to a specified timeout, in milliseconds. |
RequestProperties |
Returns an unmodifiable Map of general request properties for this connection. |
ThresholdClass |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
ThresholdType |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
Url |
The URL represents the remote object on the World Wide Web to which this connection is opened. |
URL |
Returns the value of this |
UseCaches |
Returns the value of this |
Methods
AddRequestProperty(String, String) |
Adds a general request property specified by a key-value pair. |
Clone() |
Creates and returns a copy of this object. (Inherited from Object) |
Connect() |
Opens a communications link to the resource referenced by this URL, if such a connection has not already been established. |
ConnectAsync() | |
Dispose() | (Inherited from Object) |
Dispose(Boolean) | (Inherited from Object) |
Equals(Object) |
Indicates whether some other object is "equal to" this one. (Inherited from Object) |
GetContent(Class[]) |
Retrieves the contents of this URL connection. |
GetDefaultRequestProperty(String) |
Obsolete.
Returns the value of the default request property. |
GetHashCode() |
Returns a hash code value for the object. (Inherited from Object) |
GetHeaderField(Int32) |
Returns the value for the |
GetHeaderField(String) |
Returns the value of the named header field. |
GetHeaderFieldDate(String, Int64) |
Returns the value of the named field parsed as date. |
GetHeaderFieldInt(String, Int32) |
Returns the value of the named field parsed as a number. |
GetHeaderFieldKey(Int32) |
Returns the key for the |
GetHeaderFieldLong(String, Int64) |
Returns the value of the named field parsed as a number. |
GetRequestProperty(String) |
Returns the value of the named general request property for this connection. |
GuessContentTypeFromName(String) |
Tries to determine the content type of an object, based on the specified "file" component of a URL. |
GuessContentTypeFromStream(Stream) |
Tries to determine the type of an input stream based on the characters at the beginning of the input stream. |
JavaFinalize() |
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Object) |
Notify() |
Wakes up a single thread that is waiting on this object's monitor. (Inherited from Object) |
NotifyAll() |
Wakes up all threads that are waiting on this object's monitor. (Inherited from Object) |
SetContentHandlerFactory(IContentHandlerFactory) |
Sets the |
SetDefaultRequestProperty(String, String) |
Obsolete.
Sets the default value of a general request property. |
SetHandle(IntPtr, JniHandleOwnership) |
Sets the Handle property. (Inherited from Object) |
SetRequestProperty(String, String) |
Sets the general request property. |
ToArray<T>() | (Inherited from Object) |
ToString() |
Returns a string representation of the object. (Inherited from Object) |
UnregisterFromRuntime() | (Inherited from Object) |
Wait() |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>. (Inherited from Object) |
Wait(Int64, Int32) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
Wait(Int64) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
Explicit Interface Implementations
IJavaPeerable.Disposed() | (Inherited from Object) |
IJavaPeerable.DisposeUnlessReferenced() | (Inherited from Object) |
IJavaPeerable.Finalized() | (Inherited from Object) |
IJavaPeerable.JniManagedPeerState | (Inherited from Object) |
IJavaPeerable.SetJniIdentityHashCode(Int32) | (Inherited from Object) |
IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates) | (Inherited from Object) |
IJavaPeerable.SetPeerReference(JniObjectReference) | (Inherited from Object) |
Extension Methods
JavaCast<TResult>(IJavaObject) |
Performs an Android runtime-checked type conversion. |
JavaCast<TResult>(IJavaObject) | |
GetJniTypeName(IJavaPeerable) |