Overrides java.net.URLConnection.addRequestProperty.

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.

Implements abstract java.net.URLConnection.connect.

Doc from java.net.URLConnection.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.

Exceptions

IOException:

if an I/O error occurs while opening the connection.

Overrides java.net.URLConnection.getAllowUserInteraction.

Returns the value of the allowUserInteraction field for this object.

Returns:boolean

the value of the allowUserInteraction field for this object.

See Also

java.net.URLConnection#allowUserInteraction

Overrides java.net.URLConnection.getContent.

Doc from java.net.URLConnection.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.

This is done as follows:

1. 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.
2. If no ContentHandlerFactory has yet been set up, or if the factory's createContentHandler method returns null, then the ServiceLoader mechanism is used to locate ContentHandlerFactory implementations using the system class loader. The order that factories are located is implementation specific, and an implementation is free to cache the located factories. A ServiceConfigurationError, Error or RuntimeException thrown from the createContentHandler, if encountered, will be propagated to the calling thread. The createContentHandler method of each factory, if instantiated, is invoked, with the content type, until a factory returns non-null, or all factories have been exhausted.
3. Failing that, this method tries to load a content handler class as defined by ContentHandler. If the class does not exist, or is not a subclass of ContentHandler, then an UnknownServiceException is thrown.

Exceptions

IOException:

if an I/O error occurs while getting the content.

Overrides java.net.URLConnection.getContentLength.

Doc from java.net.URLConnection.getContentLength.

Returns the value of the content-length header field.

Overrides java.net.URLConnection.getContentLengthLong.

Doc from java.net.URLConnection.getContentLengthLong.

Returns the value of the content-length header field as a long.

Overrides java.net.URLConnection.getContentType.

Doc from java.net.URLConnection.getContentType.

Returns the value of the content-type header field.

Overrides java.net.URLConnection.getDefaultUseCaches.

Returns the default value of a URLConnection's useCaches flag.

The 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.

Returns:boolean

the default value of a URLConnection's useCaches flag.

See Also

java.net.URLConnection#useCaches

Overrides java.net.URLConnection.getHeaderField.

Doc from java.net.URLConnection.getHeaderField.

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.

Overrides java.net.URLConnection.getInputStream.

Doc from java.net.URLConnection.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.

Exceptions

IOException:

if an I/O error occurs while creating the input stream.

Overrides java.net.JarURLConnection.getJarEntry.

Doc from java.net.JarURLConnection.getJarEntry.

Return the JAR entry object for this connection, if any. This method returns null if the JAR file URL corresponding to this connection points to a JAR file and not a JAR file entry.

Exceptions

IOException:

if getting the JAR file for this connection causes an IOException to be thrown.

Implements abstract java.net.JarURLConnection.getJarFile.

Doc from java.net.JarURLConnection.getJarFile.

Return the JAR file for this connection.

Exceptions

IOException:

if an IOException occurs while trying to connect to the JAR file for this connection.

Overrides java.net.URLConnection.getPermission.

Doc from java.net.URLConnection.getPermission.

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 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.

Annotations

@Override

@Deprecated

since:25

forRemoval:true

@SuppressWarnings:removal

Exceptions

IOException:

if the computation of the permission requires network or file I/O and an exception occurs while computing it.

Overrides java.net.URLConnection.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.

Returns:Map<String, List<String>>

a Map of the general request properties for this connection.

Overrides java.net.URLConnection.getRequestProperty.

Returns the value of the named general request property for this connection.

Returns:String

the value of the named general request property for this connection.

Overrides java.net.URLConnection.getUseCaches.

Returns the value of this URLConnection's useCaches field.

Returns:boolean

the value of this URLConnection's useCaches field.

See Also

java.net.URLConnection#useCaches

Overrides java.net.URLConnection.setAllowUserInteraction.

Set the value of the allowUserInteraction field of this URLConnection.

Parameters

allowuserinteraction:boolean

the new value.

See Also

java.net.URLConnection#allowUserInteraction

Overrides java.net.URLConnection.setDefaultUseCaches.

Sets the default value of the useCaches field to the specified value.

Parameters

defaultusecaches:boolean

the new value.

See Also

java.net.URLConnection#useCaches

Overrides java.net.URLConnection.setIfModifiedSince.

Sets the value of the ifModifiedSince field of this URLConnection to the specified value.

Parameters

ifmodifiedsince:long

the new value.

See Also

java.net.URLConnection#ifModifiedSince

Overrides java.net.URLConnection.setRequestProperty.

Sets the general request property.

Parameters

key:String

the keyword by which the request is known (e.g., "accept").

value:String

the value associated with it.

Overrides java.net.URLConnection.setUseCaches.

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.

See Also

java.net.URLConnection#useCaches