## org.w3c.www.protocol.http
Class HttpManager

    java.lang.Object
      |
      +--org.w3c.www.protocol.http.HttpManager

public class HttpManager
extends java.lang.Object
implements PropertyMonitoring

The client side HTTP request manager. This class is the user interface (along with the other public classes of this package) for the W3C client side library implementing HTTP. A typicall request is launched though the following sequence:

     HttpManager     manager = HttpManager.getManager() ;
     Request request = manager.createRequest() ;
     request.setMethod(HTTP.GET) ;
     request.setURL(new URL("http://www.w3.org/pub/WWW/"));
     Reply    reply = manager.runRequest(request) ;
     // Get the reply input stream that contains the actual data:
     InputStream in = reply.getInputStream() ;
     ...

Field Summary
`static java.lang.String` | `ACCEPT_ENCODING_P` Header properties - Set the accept encodings.
`static java.lang.String` | `ACCEPT_LANGUAGE_P` Header properties - Set the accept language.
`static java.lang.String` | `ACCEPT_P` Header properties - Set the accept header.
`protected int` | `conn_count`
`protected int` | `conn_max`
`static java.lang.String` | `CONN_MAX_P` The maximum number of simultaneous connectionlrus.
`protected LRUList` | `connectionsLru` The LRU list of connections.
`static java.lang.String` | `DEFAULT_ACCEPT` The default value for the `Accept` header.
`static java.lang.String` | `DEFAULT_USER_AGENT` The default value for the `User-Agent` header.
`static java.lang.String` | `FILTERS_PROP_P` The name of the property containing the ProprequestFilter to launch.
`static java.lang.String` | `MAX_STALE_P` Header properties - The allowed drift for getting cached resources.
`static java.lang.String` | `MIN_FRESH_P` Header properties - The minium freshness required on cached resources.
`static java.lang.String` | `ONLY_IF_CACHED_P` Header properties - Set the only if cached flag on requests.
`static java.lang.String` | `PROXY_HOST_P` Header properties - What is the proxy host name.
`static java.lang.String` | `PROXY_PORT_P` Header properties - What is the proxy port number.
`static java.lang.String` | `PROXY_SET_P` Header properties - Should we use a proxy ?
`static java.lang.String` | `SERVER_CLASS_P` The name of the property indicating the class of HttpServer to use.
`protected java.lang.Class` | `serverclass` The class to instantiate to create new HttpServer instances.
`protected java.util.Hashtable` | `servers` The server this manager knows about, indexed by FQDN of target servers.
`protected Request` | `template` The template request (the request we will clone to create new requests)
`protected int` | `timeout`
`static java.lang.String` | `TIMEOUT_P` The SO_TIMEOUT of the client socket.
`static java.lang.String` | `USER_AGENT_P` Header properties - Set the user agent.

Constructor Summary
`protected` | `HttpManager()` Create a new HttpManager.

Method Summary
`protected boolean` | `closeAnyConnection()` Close some connections, but pickling the least recently used ones.
`Request` | `createRequest()` Create a new default outgoing request.
`protected void` | `decrConnCount(HttpServer server)` Decrement the number of established connections.
`protected void` | `deleteConnection(org.w3c.www.protocol.http.HttpConnection conn)` The given connection has been deleted.
`protected org.w3c.www.protocol.http.HttpConnection` | `getConnection(HttpServer server)` Try reusing one of the idle connection of that server, if any.
`RequestFilter` | `getGlobalFilter(java.lang.Class cls)` Find back an instance of a global filter.
`java.lang.String` | `getGlobalHeader(java.lang.String name)` Global settings - Get a global request header default value.
`static HttpManager` | `getManager()`
`static HttpManager` | `getManager(java.util.Properties p)` Get an instance of the HTTP manager.
`ObservableProperties` | `getProperties()` Get this manager properties.
`MimeParserFactory` | `getReplyFactory()`
`java.lang.String` | `getServerKey(Request request)` Get the String key for the server instance handling that request.
`protected void` | `incrConnCount(HttpServer server)` A new client connection has been established.
`protected HttpServer` | `lookupServer(java.lang.String host, int port)` Get the appropriate server object for handling request to given target.
`static void` | `main(java.lang.String[] args)` DEBUGGING !
`protected boolean` | `negotiateConnection(HttpServer server)` One of our server handler wants to open a connection.
`protected void` | `notifyConnection(org.w3c.www.protocol.http.HttpConnection conn)` The given connection has just been created.
`void` | `notifyIdle(org.w3c.www.protocol.http.HttpConnection conn)` The given connection can be reused, but is now idle.
`void` | `notifyUse(org.w3c.www.protocol.http.HttpConnection conn)` The given connection is about to be used.
`boolean` | `propertyChanged(java.lang.String name)` PropertyMonitoring implementation - Update properties on the fly !
`Reply` | `runRequest(Request request)` Run the given request, in synchronous mode.
`void` | `setAllowUserInteraction(boolean onoff)` Allow the manager to interact with the user if needed.
`void` | `setFilter(RequestFilter filter)` Add a global filter.
`void` | `setFilter(java.net.URL[] incs, java.net.URL[] exs, RequestFilter filter)` Add a new request filter.
`void` | `setGlobalHeader(java.lang.String name, java.lang.String value)` Global settings - Define a global request header.
`void` | `setMaxConnections(int max_conn)` Global settings - Set the max number of allowed connections.
`void` | `setProxy(java.net.URL proxy)` Global settings - Set an optional proxy to use.
`void` | `setRequestTimeout(int ms)` Global settings - Set the request timeout.
`void` | `setTimeout(int timeout)` Global settings - Set the timeout on the socket This value defaults to the value of the `org.w3c.www.http.Timeout` property.
`void` | `sync()` Dump all in-memory cached state to persistent storage.
`protected boolean` | `tooManyConnections()`
`protected boolean` | `updateProxy()` Update the proxy configuration to match current properties setting.
`boolean` | `usingProxy()` Does this manager uses a proxy to fulfill requests ?
`protected void` | `waitForConnection(HttpServer server)` Wait for a connection to come up.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### SERVER_CLASS_P

    public static final java.lang.String SERVER_CLASS_P

  The name of the property indicating the class of HttpServer to use.

### FILTERS_PROP_P

    public static final java.lang.String FILTERS_PROP_P

  The name of the property containing the ProprequestFilter to launch.

### CONN_MAX_P

    public static final java.lang.String CONN_MAX_P

  The maximum number of simultaneous connectionlrus.

### TIMEOUT_P

    public static final java.lang.String TIMEOUT_P

  The SO_TIMEOUT of the client socket.

### MAX_STALE_P

    public static final java.lang.String MAX_STALE_P

  Header properties - The allowed drift for getting cached resources.

### MIN_FRESH_P

    public static final java.lang.String MIN_FRESH_P

  Header properties - The minium freshness required on cached resources.

### ONLY_IF_CACHED_P

    public static final java.lang.String ONLY_IF_CACHED_P

  Header properties - Set the only if cached flag on requests.

### USER_AGENT_P

    public static final java.lang.String USER_AGENT_P

  Header properties - Set the user agent.

### ACCEPT_P

    public static final java.lang.String ACCEPT_P

  Header properties - Set the accept header.

### ACCEPT_LANGUAGE_P

    public static final java.lang.String ACCEPT_LANGUAGE_P

  Header properties - Set the accept language.

### ACCEPT_ENCODING_P

    public static final java.lang.String ACCEPT_ENCODING_P

  Header properties - Set the accept encodings.

### PROXY_SET_P

    public static final java.lang.String PROXY_SET_P

  Header properties - Should we use a proxy ?

### PROXY_HOST_P

    public static final java.lang.String PROXY_HOST_P

  Header properties - What is the proxy host name.

### PROXY_PORT_P

    public static final java.lang.String PROXY_PORT_P

  Header properties - What is the proxy port number.

### DEFAULT_ACCEPT

    public static final java.lang.String DEFAULT_ACCEPT

  The default value for the `Accept` header.

### DEFAULT_USER_AGENT

    public static final java.lang.String DEFAULT_USER_AGENT

  The default value for the `User-Agent` header.

### serverclass

    protected java.lang.Class serverclass

  The class to instantiate to create new HttpServer instances.

### servers

    protected java.util.Hashtable servers

  The server this manager knows about, indexed by FQDN of target servers.

### template

    protected Request template

  The template request (the request we will clone to create new requests)

### connectionsLru

    protected LRUList connectionsLru

  The LRU list of connections.

### timeout

    protected int timeout

### conn_count

    protected int conn_count

### conn_max

    protected int conn_max

Constructor Detail

### HttpManager

    protected HttpManager()

  Create a new HttpManager. FIXME Making this method protected breaks the static method to create HttpManager instances (should use a factory here)
  Parameters:
    `props` - The properties from which the manager should initialize itself, or null if none are available.

Method Detail

### updateProxy

    protected boolean updateProxy()

  Update the proxy configuration to match current properties setting.
  Returns:
    A boolean, true if change was done, false otherwise.

### getProperties

    public final ObservableProperties getProperties()

  Get this manager properties.
  Returns:
    An ObservableProperties instance.

### propertyChanged

    public boolean propertyChanged(java.lang.String name)

  PropertyMonitoring implementation - Update properties on the fly !
  Specified by:
    propertyChanged in interface PropertyMonitoring
  Parameters:
    `name` - The name of the property that has changed.
  Returns:
    A boolean, true if change is accepted, false otherwise.

### setAllowUserInteraction

    public void setAllowUserInteraction(boolean onoff)

  Allow the manager to interact with the user if needed. This will, for example, allow prompting for paswords, etc.
  Parameters:
    `onoff` - Turn interaction on or off.

### getManager

    public static HttpManager getManager(java.util.Properties p)

  Get an instance of the HTTP manager. This method returns an actual instance of the HTTP manager. It may return different managers, if it decides to distribute the load on different managers (avoid the HttpManager being a bottleneck).
  Returns:
    An application wide instance of the HTTP manager.

### getManager

    public static HttpManager getManager()

### getServerKey

    public final java.lang.String getServerKey(Request request)

  Get the String key for the server instance handling that request. This method takes care of any proxy setting (it will return the key to the proxy when required.)
  Returns:
    A uniq identifier for the handling server, as a String.

### lookupServer

    protected HttpServer lookupServer(java.lang.String host,
                                      int port)
                               throws HttpException

  Get the appropriate server object for handling request to given target.
  Parameters:
    `key` - The server's key, as returned by `getServerKey`.
  Returns:
    An object complying to the HttpServer interface.
  Throws:
    HttpException - If the given host name couldn't be resolved.

### notifyUse

    public void notifyUse(org.w3c.www.protocol.http.HttpConnection conn)

  The given connection is about to be used. Update our list of available servers.
  Parameters:
    `conn` - The idle connection.

### notifyIdle

    public void notifyIdle(org.w3c.www.protocol.http.HttpConnection conn)

  The given connection can be reused, but is now idle.
  Parameters:
    `conn` - The connection that is now idle.

### notifyConnection

    protected void notifyConnection(org.w3c.www.protocol.http.HttpConnection conn)

  The given connection has just been created.
  Parameters:
    `conn` - The newly created connection.

### deleteConnection

    protected void deleteConnection(org.w3c.www.protocol.http.HttpConnection conn)

  The given connection has been deleted.
  Parameters:
    `conn` - The deleted connection.

### tooManyConnections

    protected boolean tooManyConnections()

### getConnection

    protected org.w3c.www.protocol.http.HttpConnection getConnection(HttpServer server)

  Try reusing one of the idle connection of that server, if any.
  Parameters:
    `server` - The target server.
  Returns:
    An currently idle connection to the given server.

### waitForConnection

    protected void waitForConnection(HttpServer server)
                              throws java.lang.InterruptedException

  Wait for a connection to come up.
  Parameters:
    `server,` - the target server.
  Throws:
    java.lang.InterruptedException - If interrupted..

### closeAnyConnection

    protected boolean closeAnyConnection()

  Close some connections, but pickling the least recently used ones. One third of the max number of connection is cut. This is done to eliminate the old connections that should be broken already. (no Socket.isAlive());
  Returns:
    A boolean, true if a connection was closed false otherwise.

### negotiateConnection

    protected boolean negotiateConnection(HttpServer server)

  One of our server handler wants to open a connection.
  Parameters:
    `block` - A boolean indicating whether we should block the calling thread until a token is available (otherwise, the method will just peek at the connection count, and return the appropriate result).
  Returns:
    A boolean, true if the connection can be opened straight, false otherwise.

### incrConnCount

    protected final void incrConnCount(HttpServer server)

  A new client connection has been established. This method will try to maintain a maximum number of established connections, by closing idle connections when possible.
  Parameters:
    `server` - The server that has established a new connection.

### decrConnCount

    protected final void decrConnCount(HttpServer server)

  Decrement the number of established connections.
  Parameters:
    `server` - The server that has closed one connection to its target.

### runRequest

    public Reply runRequest(Request request)
                     throws HttpException

  Run the given request, in synchronous mode. This method will launch the given request, and block the calling thread until the response headers are available.
  Parameters:
    `request` - The request to run.
  Returns:
    An instance of Reply, containing all the reply informations.
  Throws:
    HttpException - If something failed during request processing.

### getReplyFactory

    public MimeParserFactory getReplyFactory()

### setFilter

    public void setFilter(java.net.URL[] incs,
                          java.net.URL[] exs,
                          RequestFilter filter)

  Add a new request filter. Request filters are called before a request is launched, and after the reply headers are available. They allow applications to setup specific request headers (such as PICS, or PEP stuff) on the way in, and check the reply on the way out.

  Request filters are application wide: if their scope matches the current request, then they will always be aplied.

  Filter scopes are defined inclusively and exclusively

  Parameters:
    `incs` - The URL domains for which the filter should be triggered.
    `exs` - The URL domains for which the filter should not be triggered.
    `filter` - The request filter to add.

### setFilter

    public void setFilter(RequestFilter filter)

  Add a global filter. The given filter will always be invoked.
  Parameters:
    `filter` - The filter to install.

### getGlobalFilter

    public RequestFilter getGlobalFilter(java.lang.Class cls)

  Find back an instance of a global filter. This methods allow external classes to get a pointer to installed filters of a given class.
  Parameters:
    `cls` - The class of the filter to look for.
  Returns:
    A RequestFilter instance, or null if not found.

### createRequest

    public Request createRequest()

  Create a new default outgoing request. This method should always be used to create outgoing requests. It will initialize the request with appropriate default values for the various headers, and make sure that the request is enhanced by the registered request filters.
  Returns:
    An instance of Request, suitable to be launched.

### setMaxConnections

    public void setMaxConnections(int max_conn)

  Global settings - Set the max number of allowed connections. Set the maximum number of simultaneous connections that can remain opened. The manager will take care of queuing requests if this number is reached.

  This value defaults to the value of the `org.w3c.www.http.maxConnections` property.

  Parameters:
    `max_conn` - The allowed maximum simultaneous open connections.

### setTimeout

    public void setTimeout(int timeout)

  Global settings - Set the timeout on the socket

  This value defaults to the value of the `org.w3c.www.http.Timeout` property.

  Parameters:
    `timeout` - The allowed maximum microsecond before a timeout.

### setProxy

    public void setProxy(java.net.URL proxy)

  Global settings - Set an optional proxy to use. Set the proxy to which all requests should be targeted. If the `org.w3c.www.http.proxy` property is defined, it will be used as the default value.
  Parameters:
    `proxy` - The URL for the proxy to use.

### usingProxy

    public boolean usingProxy()

  Does this manager uses a proxy to fulfill requests ?
  Returns:
    A boolean.

### setRequestTimeout

    public void setRequestTimeout(int ms)

  Global settings - Set the request timeout. Once a request has been emited, the HttpManager will sit for this given number of milliseconds before the request is declared to have timed-out.

  This timeout value defaults to the value of the `org.w3c.www.http.requestTimeout` property value.

  Parameters:
    `ms` - The timeout value in milliseconds.

### setGlobalHeader

    public void setGlobalHeader(java.lang.String name,
                                java.lang.String value)

  Global settings - Define a global request header. Set a default value for some request header. Once defined, the header will automatically be defined on all outgoing requests created through the `createRequest` request.
  Parameters:
    `name` - The name of the header, case insensitive.
    `value` - It's default value.

### getGlobalHeader

    public java.lang.String getGlobalHeader(java.lang.String name)

  Global settings - Get a global request header default value.
  Parameters:
    `name` - The name of the header to get.
  Returns:
    The value for that header, as a String, or null if undefined.

### sync

    public void sync()

  Dump all in-memory cached state to persistent storage.

### main

    public static void main(java.lang.String[] args)

  DEBUGGING !