Package uk.num.net

Class NUMURLConnection

  • public final class NUMURLConnection
extends java.net.URLConnection

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String HIDE_PARAMS  
      static java.lang.String USE_POPULATOR  

      • Fields inherited from class java.net.URLConnection

        allowUserInteraction, connected, doInput, doOutput, ifModifiedSince, url, useCaches

    • Constructor Summary

      Constructors 
      Constructor Description
      NUMURLConnection​(@NonNull java.net.URL url)
      Constructs a URL connection to the specified URL.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addRequestProperty​(java.lang.String key, java.lang.String value)
      Adds a general request property specified by a key-value pair.
      void connect()
      Opens a communications link to the resource referenced by this URL, if such a connection has not already been established.
      boolean getAllowUserInteraction()
      Returns the value of the allowUserInteraction field for this object.
      java.lang.Object getContent()
      Retrieves the contents of this URL connection.
      java.lang.Object getContent​(java.lang.Class[] classes)
      Retrieves the contents of this URL connection.
      java.lang.String getContentEncoding()
      Returns the value of the content-encoding header field.
      int getContentLength()
      Returns the value of the content-length header field.
      long getContentLengthLong()
      Returns the value of the content-length header field as a long.
      java.lang.String getContentType()
      Returns the value of the content-type header field.
      long getDate()
      Returns the value of the date header field.
      boolean getDefaultUseCaches()
      Returns the default value of a URLConnection's useCaches flag.
      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.
      java.lang.String getHeaderField​(int n)
      Returns the value for the nth header field.
      java.lang.String getHeaderField​(java.lang.String name)
      Returns the value of the named header field.
      long getHeaderFieldDate​(java.lang.String name, long Default)
      Returns the value of the named field parsed as date.
      int getHeaderFieldInt​(java.lang.String name, int Default)
      Returns the value of the named field parsed as a number.
      java.lang.String getHeaderFieldKey​(int n)
      Returns the key for the nth header field.
      long getHeaderFieldLong​(java.lang.String name, long Default)
      Returns the value of the named field parsed as a number.
      java.util.Map<java.lang.String,​java.util.List<java.lang.String>> getHeaderFields()
      Returns an unmodifiable Map of the header fields.
      long getIfModifiedSince()
      Returns the value of this object's ifModifiedSince field.
      java.io.InputStream getInputStream()
      Returns an input stream that reads from this open connection.
      long getLastModified()
      Returns the value of the last-modified header field.
      java.io.OutputStream getOutputStream()
      Returns an output stream that writes to this connection.
      java.security.Permission getPermission()
      Returns a permission object representing the permission necessary to make the connection represented by this object.
      java.util.Map<java.lang.String,​java.util.List<java.lang.String>> getRequestProperties()
      Returns an unmodifiable Map of general request properties for this connection.
      java.lang.String getRequestProperty​(java.lang.String key)
      Returns the value of the named general request property for this connection.
      java.net.URL getURL()
      Returns the value of this URLConnection's URL field.
      boolean getUseCaches()
      Returns the value of this URLConnection's useCaches field.
      void setAllowUserInteraction​(boolean allowuserinteraction)
      Set the value of the allowUserInteraction field of this URLConnection.
      void setDefaultUseCaches​(boolean defaultusecaches)
      Sets the default value of the useCaches field to the specified value.
      void setDoInput​(boolean doinput)
      Sets the value of the doInput field for this URLConnection to the specified value.
      void setDoOutput​(boolean dooutput)
      Sets the value of the doOutput field for this URLConnection to the specified value.
      void setIfModifiedSince​(long ifmodifiedsince)
      Sets the value of the ifModifiedSince field of this URLConnection to the specified value.
      void setReadTimeout​(int timeout)
      Sets the read timeout to a specified timeout, in milliseconds.
      void setRequestProperty​(java.lang.String key, java.lang.String value)
      Sets the general request property.
      void setUseCaches​(boolean usecaches)
      Sets the value of the useCaches field of this URLConnection to the specified value.
      java.lang.String toString()
      Returns a String representation of this URL connection.

      • Methods inherited from class java.net.URLConnection

        getConnectTimeout, getDefaultAllowUserInteraction, getDefaultRequestProperty, getDefaultUseCaches, getFileNameMap, getReadTimeout, guessContentTypeFromName, guessContentTypeFromStream, setConnectTimeout, setContentHandlerFactory, setDefaultAllowUserInteraction, setDefaultRequestProperty, setDefaultUseCaches, setFileNameMap

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Constructor Detail

      • NUMURLConnection

        public NUMURLConnection​(@NonNull
                        @NonNull java.net.URL url)
        Constructs a URL connection to the specified URL. A connection to the object referenced by the URL is not created.
        Parameters:
        url - the specified URL.

    • Method Detail

      • setReadTimeout

        public void setReadTimeout​(int timeout)
        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().

        Overrides:
        setReadTimeout in class java.net.URLConnection
        Parameters:
        timeout - an int that specifies the timeout value to be used in milliseconds
        Throws:
        java.lang.IllegalArgumentException - if the timeout parameter is negative
        Since:
        1.5
        See Also:
        URLConnection.getReadTimeout(), InputStream.read()

      • getURL

        public java.net.URL getURL()
        Returns the value of this URLConnection's URL field.
        Overrides:
        getURL in class java.net.URLConnection
        Returns:
        the value of this URLConnection's URL field.
        See Also:
        URLConnection.url

      • getContentLength

        public 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.

        Overrides:
        getContentLength in class java.net.URLConnection
        Returns:
        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

        public long getContentLengthLong()
        Returns the value of the content-length header field as a long.
        Overrides:
        getContentLengthLong in class java.net.URLConnection
        Returns:
        the content length of the resource that this connection's URL references, or -1 if the content length is not known.
        Since:
        7.0

      • getContentType

        public java.lang.String getContentType()
        Returns the value of the content-type header field.
        Overrides:
        getContentType in class java.net.URLConnection
        Returns:
        the content type of the resource that the URL references, or null if not known.
        See Also:
        URLConnection.getHeaderField(String)

      • getContentEncoding

        public java.lang.String getContentEncoding()
        Returns the value of the content-encoding header field.
        Overrides:
        getContentEncoding in class java.net.URLConnection
        Returns:
        the content encoding of the resource that the URL references, or null if not known.
        See Also:
        URLConnection.getHeaderField(String)

      • getExpiration

        public long getExpiration()
        Returns the value of the expires header field.
        Overrides:
        getExpiration in class java.net.URLConnection
        Returns:
        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.
        See Also:
        URLConnection.getHeaderField(String)

      • getDate

        public long getDate()
        Returns the value of the date header field.
        Overrides:
        getDate in class java.net.URLConnection
        Returns:
        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.
        See Also:
        URLConnection.getHeaderField(String)

      • getLastModified

        public long getLastModified()
        Returns the value of the last-modified header field. The result is the number of milliseconds since January 1, 1970 GMT.
        Overrides:
        getLastModified in class java.net.URLConnection
        Returns:
        the date the resource referenced by this URLConnection was last modified, or 0 if not known.
        See Also:
        URLConnection.getHeaderField(String)

      • getHeaderField

        public java.lang.String getHeaderField​(java.lang.String name)
        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:
        getHeaderField in class java.net.URLConnection
        Parameters:
        name - the name of a header field.
        Returns:
        the value of the named header field, or null if there is no such field in the header.

      • getHeaderFields

        public java.util.Map<java.lang.String,​java.util.List<java.lang.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.
        Overrides:
        getHeaderFields in class java.net.URLConnection
        Returns:
        a Map of header fields
        Since:
        1.4

      • getHeaderFieldInt

        public int getHeaderFieldInt​(java.lang.String name,
                             int Default)
        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.

        Overrides:
        getHeaderFieldInt in class java.net.URLConnection
        Parameters:
        name - the name of the header field.
        Default - the default value.
        Returns:
        the value of the named field, parsed as an integer. The Default value is returned if the field is missing or malformed.

      • getHeaderFieldLong

        public long getHeaderFieldLong​(java.lang.String name,
                               long Default)
        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.

        Overrides:
        getHeaderFieldLong in class java.net.URLConnection
        Parameters:
        name - the name of the header field.
        Default - the default value.
        Returns:
        the value of the named field, parsed as a long. The Default value is returned if the field is missing or malformed.
        Since:
        7.0

      • getHeaderFieldDate

        public long getHeaderFieldDate​(java.lang.String name,
                               long Default)
        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.

        Overrides:
        getHeaderFieldDate in class java.net.URLConnection
        Parameters:
        name - the name of the header field.
        Default - a default value.
        Returns:
        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

        public java.lang.String getHeaderFieldKey​(int n)
        Returns the key for the nth header field. It returns null if there are fewer than n+1 fields.
        Overrides:
        getHeaderFieldKey in class java.net.URLConnection
        Parameters:
        n - an index, where n>=0
        Returns:
        the key for the nth header field, or null if there are fewer than n+1 fields.

      • getHeaderField

        public java.lang.String getHeaderField​(int n)
        Returns the value for the nth header field. It returns null if there are fewer than n+1fields.

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

        Overrides:
        getHeaderField in class java.net.URLConnection
        Parameters:
        n - an index, where n>=0
        Returns:
        the value of the nth header field or null if there are fewer than n+1 fields
        See Also:
        URLConnection.getHeaderFieldKey(int)

      • getContent

        public java.lang.Object getContent()
                            throws java.io.IOException
        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:

        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 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.<contentType>
          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.
        Overrides:
        getContent in class java.net.URLConnection
        Returns:
        the object fetched. The instanceof operator should be used to determine the specific kind of object returned.
        Throws:
        java.io.IOException - if an I/O error occurs while getting the content.
        See Also:
        ContentHandlerFactory.createContentHandler(String), URLConnection.getContentType(), URLConnection.setContentHandlerFactory(ContentHandlerFactory)

      • getContent

        public java.lang.Object getContent​(java.lang.Class[] classes)
                            throws java.io.IOException
        Retrieves the contents of this URL connection.
        Overrides:
        getContent in class java.net.URLConnection
        Parameters:
        classes - the Class array indicating the requested types
        Returns:
        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.
        Throws:
        java.io.IOException - if an I/O error occurs while getting the content.
        Since:
        1.3
        See Also:
        URLConnection.getContent(), ContentHandlerFactory.createContentHandler(String), URLConnection.getContent(Class[]), URLConnection.setContentHandlerFactory(ContentHandlerFactory)

      • getPermission

        public java.security.Permission getPermission()
                                       throws java.io.IOException
        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.

        Overrides:
        getPermission in class java.net.URLConnection
        Returns:
        the permission object representing the permission necessary to make the connection represented by this URLConnection.
        Throws:
        java.io.IOException - if the computation of the permission requires network or file I/O and an exception occurs while computing it.

      • getInputStream

        public java.io.InputStream getInputStream()
                                   throws java.io.IOException
        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.

        Overrides:
        getInputStream in class java.net.URLConnection
        Returns:
        an input stream that reads from this open connection.
        Throws:
        java.io.IOException - if an I/O error occurs while creating the input stream.
        See Also:
        setReadTimeout(int), URLConnection.getReadTimeout()

      • getOutputStream

        public java.io.OutputStream getOutputStream()
                                     throws java.io.IOException
        Returns an output stream that writes to this connection.
        Overrides:
        getOutputStream in class java.net.URLConnection
        Returns:
        an output stream that writes to this connection.
        Throws:
        java.io.IOException - if an I/O error occurs while creating the output stream.

      • toString

        public java.lang.String toString()
        Returns a String representation of this URL connection.
        Overrides:
        toString in class java.net.URLConnection
        Returns:
        a string representation of this URLConnection.

      • getDoInput

        public boolean getDoInput()
        Returns the value of this URLConnection's doInput flag.
        Overrides:
        getDoInput in class java.net.URLConnection
        Returns:
        the value of this URLConnection's doInput flag.
        See Also:
        setDoInput(boolean)

      • setDoInput

        public void setDoInput​(boolean doinput)
        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.

        Overrides:
        setDoInput in class java.net.URLConnection
        Parameters:
        doinput - the new value.
        Throws:
        java.lang.IllegalStateException - if already connected
        See Also:
        URLConnection.doInput, getDoInput()

      • getDoOutput

        public boolean getDoOutput()
        Returns the value of this URLConnection's doOutput flag.
        Overrides:
        getDoOutput in class java.net.URLConnection
        Returns:
        the value of this URLConnection's doOutput flag.
        See Also:
        setDoOutput(boolean)

      • setDoOutput

        public void setDoOutput​(boolean dooutput)
        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.

        Overrides:
        setDoOutput in class java.net.URLConnection
        Parameters:
        dooutput - the new value.
        Throws:
        java.lang.IllegalStateException - if already connected
        See Also:
        getDoOutput()

      • getAllowUserInteraction

        public boolean getAllowUserInteraction()
        Returns the value of the allowUserInteraction field for this object.
        Overrides:
        getAllowUserInteraction in class java.net.URLConnection
        Returns:
        the value of the allowUserInteraction field for this object.
        See Also:
        setAllowUserInteraction(boolean)

      • setAllowUserInteraction

        public void setAllowUserInteraction​(boolean allowuserinteraction)
        Set the value of the allowUserInteraction field of this URLConnection.
        Overrides:
        setAllowUserInteraction in class java.net.URLConnection
        Parameters:
        allowuserinteraction - the new value.
        Throws:
        java.lang.IllegalStateException - if already connected
        See Also:
        getAllowUserInteraction()

      • getUseCaches

        public boolean getUseCaches()
        Returns the value of this URLConnection's useCaches field.
        Overrides:
        getUseCaches in class java.net.URLConnection
        Returns:
        the value of this URLConnection's useCaches field.
        See Also:
        setUseCaches(boolean)

      • setUseCaches

        public void setUseCaches​(boolean usecaches)
        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.

        Overrides:
        setUseCaches in class java.net.URLConnection
        Parameters:
        usecaches - a boolean indicating whether or not to allow caching
        Throws:
        java.lang.IllegalStateException - if already connected
        See Also:
        getUseCaches()

      • getIfModifiedSince

        public long getIfModifiedSince()
        Returns the value of this object's ifModifiedSince field.
        Overrides:
        getIfModifiedSince in class java.net.URLConnection
        Returns:
        the value of this object's ifModifiedSince field.
        See Also:
        setIfModifiedSince(long)

      • setIfModifiedSince

        public void setIfModifiedSince​(long ifmodifiedsince)
        Sets the value of the ifModifiedSince field of this URLConnection to the specified value.
        Overrides:
        setIfModifiedSince in class java.net.URLConnection
        Parameters:
        ifmodifiedsince - the new value.
        Throws:
        java.lang.IllegalStateException - if already connected
        See Also:
        getIfModifiedSince()

      • getDefaultUseCaches

        public 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.

        Overrides:
        getDefaultUseCaches in class java.net.URLConnection
        Returns:
        the default value of a URLConnection's useCaches flag.
        See Also:
        setDefaultUseCaches(boolean)

      • setDefaultUseCaches

        public void setDefaultUseCaches​(boolean defaultusecaches)
        Sets the default value of the useCaches field to the specified value.
        Overrides:
        setDefaultUseCaches in class java.net.URLConnection
        Parameters:
        defaultusecaches - the new value.
        See Also:
        getDefaultUseCaches()

      • setRequestProperty

        public void setRequestProperty​(java.lang.String key,
                               java.lang.String value)
        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.

        Overrides:
        setRequestProperty in class java.net.URLConnection
        Parameters:
        key - the keyword by which the request is known (e.g., "Accept").
        value - the value associated with it.
        Throws:
        java.lang.IllegalStateException - if already connected
        java.lang.NullPointerException - if key is null
        See Also:
        getRequestProperty(String)

      • addRequestProperty

        public void addRequestProperty​(java.lang.String key,
                               java.lang.String value)
        Adds a general request property specified by a key-value pair. This method will not overwrite existing values associated with the same key.
        Overrides:
        addRequestProperty in class java.net.URLConnection
        Parameters:
        key - the keyword by which the request is known (e.g., "Accept").
        value - the value associated with it.
        Throws:
        java.lang.IllegalStateException - if already connected
        java.lang.NullPointerException - if key is null
        Since:
        1.4
        See Also:
        getRequestProperties()

      • getRequestProperty

        public java.lang.String getRequestProperty​(java.lang.String key)
        Returns the value of the named general request property for this connection.
        Overrides:
        getRequestProperty in class java.net.URLConnection
        Parameters:
        key - the keyword by which the request is known (e.g., "Accept").
        Returns:
        the value of the named general request property for this connection. If key is null, then null is returned.
        Throws:
        java.lang.IllegalStateException - if already connected
        See Also:
        setRequestProperty(String, String)

      • getRequestProperties

        public java.util.Map<java.lang.String,​java.util.List<java.lang.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.
        Overrides:
        getRequestProperties in class java.net.URLConnection
        Returns:
        a Map of the general request properties for this connection.
        Throws:
        java.lang.IllegalStateException - if already connected
        Since:
        1.4

      • connect

        public void connect()
             throws java.io.IOException
        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.

        Specified by:
        connect in class java.net.URLConnection
        Throws:
        java.io.IOException - if an I/O error occurs while opening the connection.
        See Also:
        URLConnection.connected, URLConnection.getConnectTimeout(), URLConnection.setConnectTimeout(int)