jhelp.util.io

Class URLConnectionCopy

java.lang.Object

java.net.URLConnection

jhelp.util.io.URLConnectionCopy

public class URLConnectionCopy
extends java.net.URLConnection

URL connection able to open a read stream that copy everything it read in same time in a file.
It does a copy while reading

Last modification : 15 sept. 2010
Version 0.0.0

Author:

JHelp

Field Summary

Fields

Modifier and Type	Field and Description
private java.net.URLConnection	connection Connection base
private java.io.File	fileCopy File where copy

Fields inherited from class java.net.URLConnection

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

Constructor Summary

Constructors

Constructor and Description
URLConnectionCopy(java.net.URL url, java.io.File fileCopy) Constructs URLConnectionCopy

Method Summary

Methods

Modifier and Type	Method and 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.
int	getConnectTimeout() Returns setting for connect timeout.
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.
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.
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 and copy the reading in the file in same time 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.
int	getReadTimeout() Returns setting for read timeout. 0 return implies that the option is disabled (i.e., timeout of infinity).
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	setConnectTimeout(int timeout) Sets a specified timeout value, in milliseconds, to be used when opening a communications link to the resource referenced by 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.

Methods inherited from class java.net.URLConnection

getContentLengthLong, getDefaultAllowUserInteraction, getDefaultRequestProperty, getFileNameMap, getHeaderFieldLong, guessContentTypeFromName, guessContentTypeFromStream, setContentHandlerFactory, setDefaultAllowUserInteraction, setDefaultRequestProperty, setFileNameMap, toString

Methods inherited from class java.lang.Object

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

Field Detail

connection

private final java.net.URLConnection connection

Connection base

fileCopy

private final java.io.File fileCopy

File where copy

Constructor Detail

URLConnectionCopy

public URLConnectionCopy(java.net.URL url,
                 java.io.File fileCopy)
                  throws java.io.IOException

Constructs URLConnectionCopy

Parameters:

url - URL to read

fileCopy - File where write the copy

Throws:

java.io.IOException - On opening connection issue or the file can't be create

Method Detail

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

See Also:

getRequestProperties(), URLConnection.addRequestProperty(java.lang.String, java.lang.String)

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.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.

See Also:

getConnectTimeout(), setConnectTimeout(int), URLConnection.connect()

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), URLConnection.getAllowUserInteraction()

getConnectTimeout

public int getConnectTimeout()

Returns setting for connect timeout.

0 return implies that the option is disabled (i.e., timeout of infinity).

Overrides:

getConnectTimeout in class java.net.URLConnection

Returns:

an int that indicates the connect timeout value in milliseconds

See Also:

setConnectTimeout(int), connect(), URLConnection.getConnectTimeout()

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.<<i>contentType</i>>
    

   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.

java.net.UnknownServiceException - if the protocol does not support the content type.

See Also:

ContentHandlerFactory.createContentHandler(java.lang.String), URLConnection.getContentType(), URLConnection.setContentHandlerFactory(java.net.ContentHandlerFactory), URLConnection.getContent()

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.

java.net.UnknownServiceException - if the protocol does not support the content type.

See Also:

URLConnection.getContent(), ContentHandlerFactory.createContentHandler(java.lang.String), URLConnection.getContent(java.lang.Class[]), URLConnection.setContentHandlerFactory(java.net.ContentHandlerFactory), URLConnection.getContent(java.lang.Class[])

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(java.lang.String), URLConnection.getContentEncoding()

getContentLength

public int getContentLength()

Returns the value of the content-length header field.

Overrides:

getContentLength 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.

See Also:

URLConnection.getContentLength()

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(java.lang.String), URLConnection.getContentType()

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(java.lang.String), URLConnection.getDate()

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), URLConnection.getDefaultUseCaches()

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), URLConnection.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), URLConnection.getDoOutput()

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(java.lang.String), URLConnection.getExpiration()

getHeaderField

public java.lang.String getHeaderField(int n)

Returns the value for the n^th 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 n^th header field or null if there are fewer than n+1 fields

See Also:

URLConnection.getHeaderFieldKey(int), URLConnection.getHeaderField(int)

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.

See Also:

URLConnection.getHeaderField(java.lang.String)

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.

See Also:

URLConnection.getHeaderFieldDate(java.lang.String, long)

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.

See Also:

URLConnection.getHeaderFieldInt(java.lang.String, int)

getHeaderFieldKey

public java.lang.String getHeaderFieldKey(int n)

Returns the key for the n^th 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 n^th header field, or null if there are fewer than n+1 fields.

See Also:

URLConnection.getHeaderFieldKey(int)

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

See Also:

URLConnection.getHeaderFields()

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), URLConnection.getIfModifiedSince()

getInputStream

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

Returns an input stream that reads and copy the reading in the file in same time 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.

java.net.UnknownServiceException - if the protocol does not support input.

See Also:

setReadTimeout(int), getReadTimeout(), URLConnection.getInputStream()

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(java.lang.String), URLConnection.getLastModified()

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.

java.net.UnknownServiceException - if the protocol does not support output.

See Also:

URLConnection.getOutputStream()

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.

See Also:

URLConnection.getPermission()

getReadTimeout

public int getReadTimeout()

Returns setting for read timeout. 0 return implies that the option is disabled (i.e., timeout of infinity).

Overrides:

getReadTimeout in class java.net.URLConnection

Returns:

an int that indicates the read timeout value in milliseconds

See Also:

setReadTimeout(int), InputStream.read(), URLConnection.getReadTimeout()

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

See Also:

URLConnection.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(java.lang.String, java.lang.String), URLConnection.getRequestProperty(java.lang.String)

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.getURL()

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), URLConnection.getUseCaches()

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(), URLConnection.setAllowUserInteraction(boolean)

setConnectTimeout

public void setConnectTimeout(int timeout)

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 implmentation of this method may ignore the specified timeout. To see the connect timeout set, please call getConnectTimeout().

Overrides:

setConnectTimeout in class java.net.URLConnection

Parameters:

timeout - an int that specifies the connect timeout value in milliseconds

Throws:

java.lang.IllegalArgumentException - if the timeout parameter is negative

See Also:

getConnectTimeout(), connect(), URLConnection.setConnectTimeout(int)

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(), URLConnection.setDefaultUseCaches(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:

getDoInput(), URLConnection.setDoInput(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(), URLConnection.setDoOutput(boolean)

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(), URLConnection.setIfModifiedSince(long)

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

See Also:

getReadTimeout(), InputStream.read(), URLConnection.setReadTimeout(int)

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-seperated 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(java.lang.String), URLConnection.setRequestProperty(java.lang.String, java.lang.String)

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(), URLConnection.setUseCaches(boolean)