org.astrogrid.samp.httpd

Class UtilServer

java.lang.Object

org.astrogrid.samp.httpd.UtilServer

public class UtilServer
extends Object

Utility class for use with HttpServer.

This class performs two functions. Firstly it provides a static getInstance() method which allows its use in a singleton-like way. The constructor is public, so singleton use is not enforced, but if you need a server but don't need exclusive control over it, obtaining one in this way will ensure that you don't start a new server (which requires a new socket and other resources) if a suitable one is already available.

Secondly, it provides some utility methods, exportResource(java.net.URL) and exportFile(java.io.File), useful for turning files or classpath resources into publicly viewable URLs, which is sometimes useful within a SAMP context (for instance when providing an Icon URL in metadata).

Since:

22 Jul 2009

Author:

Mark Taylor

Field Summary

Fields

Modifier and Type	Field and Description
static String	PORT_PROP System Property key giving a preferred port number for the server.

Constructor Summary

Constructors

Constructor and Description
UtilServer(HttpServer server) Constructor.

Method Summary

Modifier and Type	Method and Description
static void	copy(InputStream in, OutputStream out) Copies the content of an input stream to an output stream.
URL	exportFile(File file) Exposes a file in the local filesystem as a publicly visible URL.
URL	exportResource(String resource) Deprecated. since after 1.3.5, use instead exportResource(java.net.URL)
URL	exportResource(URL localUrl) Exposes a resource from a given URL as a publicly visible URL.
String	getBasePath(String txt) May be used to return a unique base path for use with this class's HttpServer.
static UtilServer	getInstance() Returns the default instance of this class.
MultiURLMapperHandler	getMapperHandler() Returns a handler for mapping local to external URLs associated with this server.
ResourceHandler	getResourceHandler() Returns a handler for general purpose resource serving associated with this server.
HttpServer	getServer() Returns the HttpServer associated with this object.
static void	setInstance(UtilServer server) Sets the default instance of this class.

Methods inherited from class java.lang.Object

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

Field Detail

PORT_PROP

public static final String PORT_PROP

System Property key giving a preferred port number for the server. If unset, or 0, or the chosen port is occupied, a system-chosen value will be used. The property name is "jsamp.server.port".

See Also:

Constant Field Values

Constructor Detail

UtilServer

public UtilServer(HttpServer server)
           throws IOException

Constructor. Note, it may be more appropriate to use the getInstance() method.

Parameters:

server - HTTP server providing base services

Throws:

IOException

Method Detail

getServer

public HttpServer getServer()

Returns the HttpServer associated with this object.

Returns:

a running server instance

getMapperHandler

public MultiURLMapperHandler getMapperHandler()

Returns a handler for mapping local to external URLs associated with this server.

Returns:

url mapping handler

getResourceHandler

public ResourceHandler getResourceHandler()

Returns a handler for general purpose resource serving associated with this server.

Returns:

resource serving handler

exportResource

public URL exportResource(URL localUrl)
                   throws IOException

Exposes a resource from a given URL as a publicly visible URL. This is typically used if the given localUrl is only visible locally, for instance on this JVM's classpath.

Parameters:

localUrl - URL visible at least within this JVM

Returns:

URL for external reference to the resource

Throws:

IOException

exportResource

public URL exportResource(String resource)
                   throws IOException

Deprecated. since after 1.3.5, use instead exportResource(java.net.URL)

Exposes a resource from the JVM's classpath as a publicly visible URL. The classloader of this class is used, which may not be the right one for the resource in question. For that reason, this utility method is deprecated in favour of the overloaded method that takes a URL.

Parameters:

resource - fully qualified path to a resource in the current classpath; separators are "/" characters

Returns:

URL for external reference to the resource

Throws:

IOException

exportFile

public URL exportFile(File file)
               throws IOException

Exposes a file in the local filesystem as a publicly visible URL.

Parameters:

file - a file on a filesystem visible from the local host

Returns:

URL for external reference to the resource

Throws:

IOException

getBasePath

public String getBasePath(String txt)

May be used to return a unique base path for use with this class's HttpServer. If all users of this server use this method to get base paths for use with different handlers, nameclash avoidance is guaranteed.

Parameters:

txt - basic text for base path

Returns:

base path; will likely bear some resemblance to txt, but may be adjusted to ensure uniqueness

getInstance

public static UtilServer getInstance()
                              throws IOException

Returns the default instance of this class. The first time this method is called a new daemon UtilServer is (lazily) created, and started. Any subsequent calls will return the same object, unless getInstance() is called.

Returns:

default instance of this class

Throws:

IOException

setInstance

public static void setInstance(UtilServer server)

Sets the default instance of this class.

Parameters:

server - default instance to be returned by getInstance()

copy

public static void copy(InputStream in,
                        OutputStream out)
                 throws IOException

Copies the content of an input stream to an output stream. The input stream is always closed on exit; the output stream is not.

Parameters:

in - input stream

out - output stream

Throws:

IOException