net.jini.jeri.http

Class HttpEndpoint

java.lang.Object

net.jini.jeri.http.HttpEndpoint

All Implemented Interfaces:

Serializable, Endpoint, TrustEquivalence

public final class HttpEndpoint
extends Object
implements Endpoint, TrustEquivalence, Serializable

An implementation of the Endpoint abstraction that uses HTTP messages sent over TCP sockets (instances of Socket) for the underlying communication mechanism.

HttpEndpoint instances contain a host name and a TCP port number, as well as an optional SocketFactory for customizing the type of Socket to use. The host name and port number are used as the remote address to connect to when making socket connections. Note that constructing an HttpEndpoint with a SocketFactory instance that produces SSL sockets does not result in an endpoint that is fully HTTPS capable.

HttpEndpoint instances map outgoing requests to HTTP request/response messages; when possible, underlying TCP connections are reused for multiple non-overlapping outgoing requests. Outbound request data is sent as the entity-body of an HTTP POST request; inbound response data is received as the entity-body of the corresponding HTTP response message. For information on HTTP, refer to RFC 2616.

HttpEndpoint can be configured via system properties to send HTTP messages through an intermediary HTTP proxy server. It also supports basic and digest HTTP authentication, specified in RFC 2617. The mechanisms involved in configuring each of these features are the same as those used by HttpURLConnection; for details, see the net.jini.jeri.http package documentation.

A SocketFactory used with an HttpEndpoint should be serializable and must implement Object.equals to obey the guidelines that are specified for equals methods of Endpoint instances.

Since:

2.0

See Also:

HttpServerEndpoint, Serialized Form

Method Summary

Modifier and Type	Method and Description
boolean	checkTrustEquivalence(Object obj) Returns true if the specified object (which is not yet known to be trusted) is equivalent in trust, content, and function to this known trusted object, and false otherwise.
boolean	equals(Object obj) Compares the specified object with this HttpEndpoint for equality.
String	getHost() Returns the host that this HttpEndpoint connects to.
static HttpEndpoint	getInstance(String host, int port) Returns an HttpEndpoint instance for the given host name and TCP port number.
static HttpEndpoint	getInstance(String host, int port, SocketFactory sf) Returns an HttpEndpoint instance for the given host name and TCP port number that contains the given SocketFactory.
int	getPort() Returns the TCP port that this HttpEndpoint connects to.
SocketFactory	getSocketFactory() Returns the SocketFactory that this endpoint uses to create Socket objects.
int	hashCode() Returns the hash code value for this HttpEndpoint.
OutboundRequestIterator	newRequest(InvocationConstraints constraints) Returns an OutboundRequestIterator to use to send a new request to this remote endpoint using the specified constraints.
String	toString() Returns a string representation of this HttpEndpoint.

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static HttpEndpoint getInstance(String host,
                                       int port)

Returns an HttpEndpoint instance for the given host name and TCP port number. Note that if HTTP proxying is in effect, then an explicit host name or IP address (i.e., not "localhost") must be provided, or else the returned HttpEndpoint will be unable to properly send requests through the proxy.

The SocketFactory contained in the returned HttpEndpoint will be null, indicating that this endpoint will create Socket objects directly.

Parameters:

host - the host for the endpoint to connect to

port - the TCP port on the given host for the endpoint to connect to

Returns:

an HttpEndpoint instance

Throws:

IllegalArgumentException - if the port number is out of the range 1 to 65535 (inclusive)

NullPointerException - if host is null

getInstance

public static HttpEndpoint getInstance(String host,
                                       int port,
                                       SocketFactory sf)

Returns an HttpEndpoint instance for the given host name and TCP port number that contains the given SocketFactory. Note that if HTTP proxying is in effect, then an explicit host name or IP address (i.e., not "localhost") must be provided, or else the returned HttpEndpoint will be unable to properly send requests through the proxy.

If the socket factory argument is null, then this endpoint will create Socket objects directly.

Parameters:

host - the host for the endpoint to connect to

port - the TCP port on the given host for the endpoint to connect to

sf - the SocketFactory to use for this HttpEndpoint, or null

Returns:

an HttpEndpoint instance

Throws:

IllegalArgumentException - if the port number is out of the range 1 to 65535 (inclusive)

NullPointerException - if host is null

getHost

public String getHost()

Returns the host that this HttpEndpoint connects to.

Returns:

the host that this endpoint connects to

getPort

public int getPort()

Returns the TCP port that this HttpEndpoint connects to.

Returns:

the TCP port that this endpoint connects to

getSocketFactory

public SocketFactory getSocketFactory()

Returns the SocketFactory that this endpoint uses to create Socket objects.

Returns:

the socket factory that this endpoint uses to create sockets, or null if this endpoint creates sockets directly

newRequest

public OutboundRequestIterator newRequest(InvocationConstraints constraints)

Returns an OutboundRequestIterator to use to send a new request to this remote endpoint using the specified constraints.

The constraints must be the complete, absolute constraints for the request.

The returned OutboundRequestIterator's next method behaves as follows:

Initiates an attempt to communicate the request to this remote endpoint.

When the implementation of this method needs to create a new Socket, it will do so by invoking one of the createSocket methods on the SocketFactory of this HttpEndpoint (which produced this iterator) if non-null, or it will create a Socket directly otherwise.

When the implementation needs to connect a Socket, if the host name to connect to (if an HTTP proxy is to be used for the communication, the proxy's host name; otherwise, this HttpEndpoint's host name) resolves to multiple addresses (according to InetAddress.getAllByName), it attempts to connect to the first resolved address; if that attempt fails with an IOException or (as is possible in the case that an HTTP proxy is not to be used) a SecurityException, it then attempts to connect to the next address; and this iteration continues as long as there is another resolved address and the attempt to connect to the previous address fails with an IOException or a SecurityException. If the host name resolves to just one address, the implementation makes one attempt to connect to that address. If the host name does not resolve to any addresses (InetAddress.getAllByName would throw an UnknownHostException), the implementation still makes an attempt to connect the Socket to that host name, which could result in an UnknownHostException. If the final connection attempt fails with an IOException or a SecurityException, then if any connection attempt failed with an IOException, this method throws an IOException, and otherwise (if all connection attempts failed with a SecurityException), this method throws a SecurityException.

If there is a security manager and an HTTP proxy is to be used for the communication, the security manager's checkConnect method is invoked with this HttpEndpoint's host and port; if this results in a SecurityException, this method throws that exception.

If there is a security manager and an HTTP proxy is not to be used for the communication:

• If a new connection is to be created, the security manager's checkConnect method is invoked with this HttpEndpoint's host and -1 for the port; if this results in a SecurityException, this method throws that exception. checkConnect is also invoked for each connection attempt, with the remote IP address (or the host name, if it could not be resolved) and port to connect to; this could result in a SecurityException for that attempt. (Note that the implementation may carry out these security checks indirectly, such as through invocations of InetAddress.getAllByName or Socket's constructors or connect method.)

• In order to reuse an existing connection for the communication, the current security context must have all of the permissions that would be necessary if the connection were being created. Specifically, it must be possible to invoke checkConnect in the current security context with this HttpEndpoint's host and -1 for the port without resulting in a SecurityException, and it also must be possible to invoke checkConnect with the remote IP address and port of the Socket without resulting in a SecurityException (if the remote socket address is unresolved, its host name is used instead). If no existing connection satisfies these requirements, then this method must behave as if there are no existing connections.

Throws NoSuchElementException if this iterator does not support making another attempt to communicate the request (that is, if hasNext would return false).

Throws IOException if an I/O exception occurs while performing this operation, such as if a connection attempt timed out or was refused.

Throws SecurityException if there is a security manager and an invocation of its checkConnect method fails.

Specified by:

newRequest in interface Endpoint

Parameters:

constraints - the complete, absolute constraints

Returns:

an OutboundRequestIterator to use to send a new request to this remote endpoint

Throws:

NullPointerException - if constraints is null

hashCode

public int hashCode()

Returns the hash code value for this HttpEndpoint.

Overrides:

hashCode in class Object

Returns:

the hash code value for this HttpEndpoint

equals

public boolean equals(Object obj)

Compares the specified object with this HttpEndpoint for equality.

This method returns true if and only if

• the specified object is also an HttpEndpoint,
• the host and port in the specified object are equal to the host and port in this object, and
• either this object and the specified object both have no SocketFactory or the SocketFactory in the specified object has the same class and is equal to the one in this object.

Overrides:

equals in class Object

Parameters:

obj - the object to compare with

Returns:

true if obj is equivalent to this object; false otherwise

checkTrustEquivalence

public boolean checkTrustEquivalence(Object obj)

Returns true if the specified object (which is not yet known to be trusted) is equivalent in trust, content, and function to this known trusted object, and false otherwise.

This method returns true if and only if

• the specified object is also an HttpEndpoint,
• the host and port in the specified object are equal to the host and port in this object, and
• either this object and the specified object both have no SocketFactory or the SocketFactory in the specified object has the same class and is equal to the one in this object.

Specified by:

checkTrustEquivalence in interface TrustEquivalence

Parameters:

obj - object to check that is not yet known to be trusted

Returns:

true if the specified object (that is not yet known to be trusted) is equivalent in trust, content, and function to this known trusted object, and returns false otherwise

toString

public String toString()

Returns a string representation of this HttpEndpoint.

Overrides:

toString in class Object

Returns:

a string representation of this HttpEndpoint