Package org.jeegen.jee6.util

Class Download

java.lang.Object

org.jeegen.jee6.util.Download

All Implemented Interfaces:

Serializable

public class Download
extends Object
implements Serializable

This class helps downloading binary file via the HTTP protocol.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
Download(String url)	The constructor specifies the URL.
Download(String url, int timeout)	The constructor specifies the URL.

Method Summary

Modifier and Type	Method	Description
static long	copy(InputStream is, OutputStream os)	This method copies data from an InputStream directly into an OutputStream.
byte[]	downloadArray()	This method downloads a HTTP resource and returns it as an byte array.
BufferedImage	downloadImage()	This method returns a BufferedImage.
boolean	getFollowRedirect()	This method returns a flag whether this download instance should follow redirects
String	getMimeType()	This getter returns the mime type of the downloaded byte array.
int	getTimeout()	This method returns the connection timeout.
String	getUrl()	This method returns the used URL.
static BufferedImage	parse(byte[] buffer)	This method converts an image as byte array into a BufferedImage.
static byte[]	read(InputStream is, int len)	This method reads a defined length from an InputStream into a byte array.
static InetAddress	resolve(String fqhn)	This method resolves a full qualified hostname into an IP address.
void	setFollowRedirect(boolean redirect)	This method sets the behavior concerning redirects.
void	setTimeout(int timeout)	This method sets a new timeout.

Methods inherited from class java.lang.Object

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

Constructor Detail

Download

public Download(String url,
                int timeout)
         throws MalformedURLException

The constructor specifies the URL.

Parameters:

url - The URL for downloading.

timeout - The timeout for a download request in milliseconds.

Throws:

MalformedURLException - Thrown if the URL is malformed.

Download

public Download(String url)
         throws MalformedURLException

The constructor specifies the URL.

Parameters:

url - The URL for downloading.

Throws:

MalformedURLException - Thrown if the URL is malformed.

Method Detail

downloadImage

public BufferedImage downloadImage()
                            throws IOException

This method returns a BufferedImage.

Returns:

The downloaded image.

Throws:

IOException - Thrown if something went wrong.

downloadArray

public byte[] downloadArray()
                     throws IOException

This method downloads a HTTP resource and returns it as an byte array.

Returns:

The downloaded byte array.

Throws:

IOException - Thrown if womething went wrong.

parse

public static BufferedImage parse(byte[] buffer)
                           throws IOException

This method converts an image as byte array into a BufferedImage.

Parameters:

buffer - The image as byte array.

Returns:

The resulting BufferedImage.

Throws:

IOException - Thrown if something went wrong.

getMimeType

public String getMimeType()

This getter returns the mime type of the downloaded byte array. This is only defined after using downloadArray(), otherwise the return value is always null.

Returns:

The mime type of the downloadArray() method call or null otherwise.

getUrl

public String getUrl()

This method returns the used URL.

Returns:

The used URL.

getTimeout

public int getTimeout()

This method returns the connection timeout.

Returns:

The connection timeout.

setTimeout

public void setTimeout(int timeout)

This method sets a new timeout.

Parameters:

timeout - The new timeout.

getFollowRedirect

public boolean getFollowRedirect()

This method returns a flag whether this download instance should follow redirects

Returns:

Flag if this instance should process redirects.

setFollowRedirect

public void setFollowRedirect(boolean redirect)

This method sets the behavior concerning redirects.

Parameters:

redirect - The flag which sets the redirect behavior of this instance.

resolve

public static InetAddress resolve(String fqhn)
                           throws UnknownHostException

This method resolves a full qualified hostname into an IP address.

Parameters:

fqhn - The hostname to resolve.

Returns:

The IP address if resolvable.

Throws:

UnknownHostException - If the hostname cannot be resolved.

read

public static byte[] read(InputStream is,
                          int len)
                   throws IOException

This method reads a defined length from an InputStream into a byte array. The InputStream is closed after reading.

Parameters:

is - The InputStream

len - The length of data inside the InputStream.

Returns:

The resulting byte array

Throws:

IOException - on read error.

copy

public static long copy(InputStream is,
                        OutputStream os)
                 throws IOException

This method copies data from an InputStream directly into an OutputStream. The amount of written bytes is returned. Both streams are not closed after copy.

Parameters:

is - The InputStream to read from.

os - The OutputStream to write to.

Returns:

The amount of written bytes copied.

Throws:

IOException - If some IO went wrong.