Class ProxySelector

java.lang.Object
java.net.ProxySelector
public abstract class ProxySelector extends Object
Selects the proxy server to use, if any, when connecting to the network resource referenced by a URL. A proxy selector is a concrete sub-class of this class and is registered by invoking the setDefault method. The currently registered proxy selector can be retrieved by calling getDefault method.

When a proxy selector is registered, for instance, a subclass of URLConnection class should call the select method for each URL request so that the proxy selector can decide if a direct, or proxied connection should be used. The select method returns an iterator over a collection with the preferred connection approach.

If a connection cannot be established to a proxy (PROXY or SOCKS) servers then the caller should call the proxy selector's connectFailed method to notify the proxy selector that the proxy server is unavailable.

The default proxy selector does enforce a set of System Properties related to proxy settings.

Since:
1.5

  • Constructor Summary

    Constructors
    Constructor
    Description
    ProxySelector()
    Constructor for subclasses to call.

  • Method Summary

    Modifier and Type
    Method
    Description
    abstract void
    connectFailed(URI uri, SocketAddress sa, IOException ioe)
    Called to indicate that a connection could not be established to a proxy/socks server.
    static ProxySelector
    getDefault()
    Gets the system-wide proxy selector.
    static ProxySelector
    of(InetSocketAddress proxyAddress)
    Returns a ProxySelector which uses the given proxy address for all HTTP and HTTPS requests.
    abstract List<Proxy>
    select(URI uri)
    Selects all the applicable proxies based on the protocol to access the resource with and a destination address to access the resource at.
    static void
    setDefault(ProxySelector ps)
    Sets (or unsets) the system-wide proxy selector.

    Methods declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Creates and returns a copy of this object.
    boolean
    equals(Object obj)
    Indicates whether some other object is "equal to" this one.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    Finalization is deprecated and subject to removal in a future release.
    final Class<?>
    getClass()
    Returns the runtime class of this Object.
    int
    hashCode()
    Returns a hash code value for this object.
    final void
    notify()
    Wakes up a single thread that is waiting on this object's monitor.
    final void
    notifyAll()
    Wakes up all threads that are waiting on this object's monitor.
    String
    toString()
    Returns a string representation of the object.
    final void
    wait()
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
    final void
    wait(long timeoutMillis)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
    final void
    wait(long timeoutMillis, int nanos)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

  • Constructor Details

    • ProxySelector

      public ProxySelector()
      Constructor for subclasses to call.

  • Method Details

    • getDefault

      public static ProxySelector getDefault()
      Gets the system-wide proxy selector.
      Returns:
      the system-wide ProxySelector
      Since:
      1.5
      See Also:

    • setDefault

      public static void setDefault(ProxySelector ps)
      Sets (or unsets) the system-wide proxy selector. Note: non-standard protocol handlers may ignore this setting.
      Parameters:
      ps - The HTTP proxy selector, or null to unset the proxy selector.
      Since:
      1.5
      See Also:

    • select

      public abstract List<Proxy> select(URI uri)
      Selects all the applicable proxies based on the protocol to access the resource with and a destination address to access the resource at. The format of the URI is defined as follows:
      • http URI for http connections
      • https URI for https connections
      • socket://host:port
        for tcp client sockets connections
      Parameters:
      uri - The URI that a connection is required to
      Returns:
      a List of Proxies. Each element in the List is of type Proxy; when no proxy is available, the list will contain one element of type Proxy that represents a direct connection.
      Throws:
      IllegalArgumentException - if the argument is null or if the protocol or host cannot be determined from the provided uri

    • connectFailed

      public abstract void connectFailed(URI uri, SocketAddress sa, IOException ioe)
      Called to indicate that a connection could not be established to a proxy/socks server. An implementation of this method can temporarily remove the proxies or reorder the sequence of proxies returned by select(URI), using the address and the IOException caught when trying to connect.
      Parameters:
      uri - The URI that the proxy at sa failed to serve.
      sa - The socket address of the proxy/SOCKS server
      ioe - The I/O exception thrown when the connect failed.
      Throws:
      IllegalArgumentException - if either argument is null

    • of

      public static ProxySelector of(InetSocketAddress proxyAddress)
      Returns a ProxySelector which uses the given proxy address for all HTTP and HTTPS requests. If proxyAddress is null then proxying is disabled.
      Parameters:
      proxyAddress - The address of the proxy
      Returns:
      a ProxySelector
      Since:
      9