oranjestad.commons.io
Class URLResource

java.lang.Object
  oranjestad.commons.io.AbstractResource
      oranjestad.commons.io.URLResource

All Implemented Interfaces:

Resource

Direct Known Subclasses:

ClassPathResource

public class URLResource
extends AbstractResource

Resource over a URL object. URL's are typically used as read only references, but URLs can supported write semantics. This resource will attempt to support writes if the underlying protocol supports them.

Usage

 URLResource resource = new URLResource( new URL("..."));
 

Notes

This resource supports ant style property expansion. An ant property reference ${property name} will be expanded before converting strings to URLs.

Since:

1.3

Author:

Bryant Harris

Constructor Summary

protected	URLResource() Internal constructor used by subclasses.
	URLResource(java.lang.String urlString) Creates a URL resource based on the supplied URL string.
	URLResource(java.net.URL theURL) Creates a URL resource over the supplied URL.

Method Summary

boolean	canReopen() Flag that lets you check if this resource supports reopening of the InputStream.
boolean	equals(java.lang.Object o)
boolean	exists() Attempts to open a connection to the URL, if the connection is succesful then the resource is considered to exist.
java.io.InputStream	getInputStream() An open input stream at the beginning of the resource.
java.io.OutputStream	getOutputStream() Attempts to obtain an output stream to the resource identified by the URL.
int	hashCode()
boolean	isReadOnly() Flag that lets you check if this resource supports writes.
void	setReadOnly(boolean flag) Sets the read only flag.
java.lang.String	toString()

Methods inherited from class oranjestad.commons.io.AbstractResource

expand

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

URLResource

public URLResource(java.net.URL theURL)

Creates a URL resource over the supplied URL.

Parameters:

theURL - The URL to read/write from.

Since:

1.3

URLResource

public URLResource(java.lang.String urlString)
            throws java.net.MalformedURLException

Creates a URL resource based on the supplied URL string.

Parameters:

urlString - The URL string (can include ant style properties).

Throws:

java.net.MalformedURLException - If the string specifies an unknown protocol

Since:

1.3

URLResource

protected URLResource()

Internal constructor used by subclasses.

Since:

1.3

Method Detail

setReadOnly

public void setReadOnly(boolean flag)

Sets the read only flag. This flag in no way alters the underlying URL object but instead instructs this resource to not attempt ever write to this URL.

When true, this flag delegates to the actual URL protocol, which itself may not support writes.

Parameters:

flag - Whether or not to attempt writes (true no writes, false will attempt writes).

Since:

1.3

getInputStream

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

Description copied from interface: Resource

An open input stream at the beginning of the resource. If the resource doesn not support reopening, this method might throw an IllegalStateException. Otherwise subsequent calls to this method return a new input stream set to the beginning of the data stream.

Returns:

The input stream over the URL.

Throws:

java.io.IOException - If an I/O related error occurs.

Since:

1.3

getOutputStream

public java.io.OutputStream getOutputStream()
                                     throws java.io.IOException,
                                            java.lang.IllegalStateException

Attempts to obtain an output stream to the resource identified by the URL. This method might fail if the underlying URL protocol does not support writes.

Returns:

An open output stream (only at the beginning if the resource has not been previously opened and remains unclosed).

Throws:

java.io.IOException - If an I/O related error occurs.

java.lang.IllegalStateException

isReadOnly

public boolean isReadOnly()

Description copied from interface: Resource

Flag that lets you check if this resource supports writes.

Returns:

true if this resource is configured to be read only, or if the underlying protocol indicates it is not read only.

Since:

1.3

canReopen

public boolean canReopen()

Description copied from interface: Resource

Flag that lets you check if this resource supports reopening of the InputStream. Some resources can only be read once.

Returns:

true

Since:

1.3

exists

public boolean exists()

Attempts to open a connection to the URL, if the connection is succesful then the resource is considered to exist.

Returns:

true if the associated url can be connected to, otherwise false.

Since:

1.3

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

The external form of the URL.

Since:

1.3

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

Returns:

The URL's hashcode.

Since:

1.3

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

Parameters:

o - The object to compare against.

Returns:

true if o is a URLResource over an equal URL object, otherwise false.

Since:

1.3