org.apache.commons.httpclient
Class HttpConnection

java.lang.Object
  org.apache.commons.httpclient.HttpConnection

public class HttpConnection
extends Object

An abstraction of an HTTP InputStream and OutputStream pair, together with the relevant attributes.

The following options are set on the socket before getting the input/output streams in the open() method:

Socket Method	Sockets Option	Configuration
Socket.setTcpNoDelay(boolean)	SO_NODELAY	HttpConnectionParams.setTcpNoDelay(boolean)
Socket.setSoTimeout(int)	SO_TIMEOUT	HttpConnectionParams.setSoTimeout(int)
Socket.setSendBufferSize(int)	SO_SNDBUF	HttpConnectionParams.setSendBufferSize(int)
Socket.setReceiveBufferSize(int)	SO_RCVBUF	HttpConnectionParams.setReceiveBufferSize(int)

Version:

$Revision: 327792 $ $Date: 2005-10-23 15:34:28 +0200 (So, 23 Okt 2005) $

Author:

Rod Waldhoff, Sean C. Sullivan, Ortwin Glueck, Jeff Dever, Mike Bowler, Oleg Kalnichevski, Michael Becke, Eric E Johnson, Laura Werner

Field Summary

protected boolean

isOpen Whether or not the connection is connected.

Constructor Summary

HttpConnection(HostConfiguration hostConfiguration)
Creates a new HTTP connection for the given host configuration.

HttpConnection(String host, int port)
Creates a new HTTP connection for the given host and port.

HttpConnection(String host, int port, Protocol protocol)
Creates a new HTTP connection for the given host and port using the given protocol.

HttpConnection(String proxyHost, int proxyPort, String host, int port)
Creates a new HTTP connection for the given host and port via the given proxy host and port using the default protocol.

HttpConnection(String proxyHost, int proxyPort, String host, int port, Protocol protocol)
Creates a new HTTP connection for the given host with the virtual alias and port via the given proxy host and port using the given protocol.

Method Summary

protected void	assertNotOpen() Throws an IllegalStateException if the connection is already open.
protected void	assertOpen() Throws an IllegalStateException if the connection is not open.
void	close() Closes the socket and streams.
boolean	closeIfStale() Closes the connection if stale.
protected void	closeSocketAndStreams() Closes everything out.
void	flushRequestOutputStream() Flushes the output request stream.
String	getHost() Returns the host.
HttpConnectionManager	getHttpConnectionManager() Returns the httpConnectionManager.
InputStream	getLastResponseInputStream() Returns the stream used to read the last response's body.
InetAddress	getLocalAddress() Return the local address used when creating the connection.
HttpConnectionParams	getParams() Returns HTTP protocol parameters associated with this method.
int	getPort() Returns the port of the host.
Protocol	getProtocol() Returns the protocol used to establish the connection.
String	getProxyHost() Returns the proxy host.
int	getProxyPort() Returns the port of the proxy host.
OutputStream	getRequestOutputStream() Returns an OutputStream suitable for writing the request.
InputStream	getResponseInputStream() Return a InputStream suitable for reading the response.
int	getSendBufferSize() Gets the socket's sendBufferSize.
protected Socket	getSocket() Returns the connection socket.
protected boolean	isLocked() Tests if the connection is locked.
boolean	isOpen() Tests if the connection is open.
boolean	isProxied() Returns true if the connection is established via a proxy, false otherwise.
boolean	isResponseAvailable() Tests if input data avaialble.
boolean	isResponseAvailable(int timeout) Tests if input data becomes available within the given period time in milliseconds.
boolean	isSecure() Returns true if the connection is established over a secure protocol.
protected boolean	isStale() Determines whether this connection is "stale", which is to say that either it is no longer open, or an attempt to read the connection would fail.
boolean	isTransparent() Indicates if the connection is completely transparent from end to end.
void	open() Establishes a connection to the specified host and port (via a proxy if specified).
void	print(String data, String charset) Writes the specified String (as bytes) to the output stream.
void	printLine() Writes "\r\n".getBytes() to the output stream.
void	printLine(String data, String charset) Writes the specified String (as bytes), followed by "\r\n".getBytes() to the output stream.
String	readLine(String charset) Reads up to "\n" from the (unchunked) input stream.
void	releaseConnection() Releases the connection.
void	setFilter(WireLogInputStream in, org.apache.commons.httpclient.WireLogOutputStream out) Set the input and out filter to use.
void	setHost(String host) Sets the host to connect to.
void	setHttpConnectionManager(HttpConnectionManager httpConnectionManager) Sets the httpConnectionManager.
void	setLastResponseInputStream(InputStream inStream) Set the state to keep track of the last response for the last request.
void	setLocalAddress(InetAddress localAddress) Set the local address used when creating the connection.
protected void	setLocked(boolean locked) Locks or unlocks the connection.
void	setParams(HttpConnectionParams params) Assigns HTTP protocol parameters for this method.
void	setPort(int port) Sets the port to connect to.
void	setProtocol(Protocol protocol) Sets the protocol used to establish the connection
void	setProxyHost(String host) Sets the host to proxy through.
void	setProxyPort(int port) Sets the port of the host to proxy through.
void	setSocketTimeout(int timeout) Sets SO_TIMEOUT value directly on the underlying socket.
void	tunnelCreated() Instructs the proxy to establish a secure tunnel to the host.
void	write(byte[] data) Writes the specified bytes to the output stream.
void	write(byte[] data, int offset, int length) Writes length bytes in data starting at offset to the output stream.
void	writeLine() Writes "\r\n".getBytes() to the output stream.
void	writeLine(byte[] data) Writes the specified bytes, followed by "\r\n".getBytes() to the output stream.

Methods inherited from class java.lang.Object

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

Field Detail

isOpen

protected boolean isOpen

Whether or not the connection is connected.

Constructor Detail

HttpConnection

public HttpConnection(String host,
                      int port)

Creates a new HTTP connection for the given host and port.

Parameters:

host - the host to connect to

port - the port to connect to

HttpConnection

public HttpConnection(String host,
                      int port,
                      Protocol protocol)

Creates a new HTTP connection for the given host and port using the given protocol.

Parameters:

host - the host to connect to

port - the port to connect to

protocol - the protocol to use

HttpConnection

public HttpConnection(String proxyHost,
                      int proxyPort,
                      String host,
                      int port)

Creates a new HTTP connection for the given host and port via the given proxy host and port using the default protocol.

Parameters:

proxyHost - the host to proxy via

proxyPort - the port to proxy via

host - the host to connect to

port - the port to connect to

HttpConnection

public HttpConnection(HostConfiguration hostConfiguration)

Creates a new HTTP connection for the given host configuration.

Parameters:

hostConfiguration - the host/proxy/protocol to use

HttpConnection

public HttpConnection(String proxyHost,
                      int proxyPort,
                      String host,
                      int port,
                      Protocol protocol)

Creates a new HTTP connection for the given host with the virtual alias and port via the given proxy host and port using the given protocol.

Parameters:

proxyHost - the host to proxy via

proxyPort - the port to proxy via

host - the host to connect to. Parameter value must be non-null.

port - the port to connect to

protocol - The protocol to use. Parameter value must be non-null.

Method Detail

getSocket

protected Socket getSocket()

Returns the connection socket.

Returns:

the socket.

Since:

3.0

getHost

public String getHost()

Returns the host.

Returns:

the host.

setHost

public void setHost(String host)
             throws IllegalStateException

Sets the host to connect to.

Parameters:

host - the host to connect to. Parameter value must be non-null.

Throws:

IllegalStateException - if the connection is already open

getPort

public int getPort()

Returns the port of the host. If the port is -1 (or less than 0) the default port for the current protocol is returned.

Returns:

the port.

setPort

public void setPort(int port)
             throws IllegalStateException

Sets the port to connect to.

Parameters:

port - the port to connect to

Throws:

IllegalStateException - if the connection is already open

getProxyHost

public String getProxyHost()

Returns the proxy host.

Returns:

the proxy host.

setProxyHost

public void setProxyHost(String host)
                  throws IllegalStateException

Sets the host to proxy through.

Parameters:

host - the host to proxy through.

Throws:

IllegalStateException - if the connection is already open

getProxyPort

public int getProxyPort()

Returns the port of the proxy host.

Returns:

the proxy port.

setProxyPort

public void setProxyPort(int port)
                  throws IllegalStateException

Sets the port of the host to proxy through.

Parameters:

port - the port of the host to proxy through.

Throws:

IllegalStateException - if the connection is already open

isSecure

public boolean isSecure()

Returns true if the connection is established over a secure protocol.

Returns:

true if connected over a secure protocol.

getProtocol

public Protocol getProtocol()

Returns the protocol used to establish the connection.

Returns:

The protocol

setProtocol

public void setProtocol(Protocol protocol)

Sets the protocol used to establish the connection

Parameters:

protocol - The protocol to use.

Throws:

IllegalStateException - if the connection is already open

getLocalAddress

public InetAddress getLocalAddress()

Return the local address used when creating the connection. If null, the default address is used.

Returns:

InetAddress the local address to be used when creating Sockets

setLocalAddress

public void setLocalAddress(InetAddress localAddress)

Set the local address used when creating the connection. If unset or null, the default address is used.

Parameters:

localAddress - the local address to use

isOpen

public boolean isOpen()

Tests if the connection is open.

Returns:

true if the connection is open

closeIfStale

public boolean closeIfStale()
                     throws IOException

Closes the connection if stale.

Returns:

true if the connection was stale and therefore closed, false otherwise.

Throws:

IOException

Since:

3.0

See Also:

isStale()

isStale

protected final boolean isStale()
                         throws IOException

Determines whether this connection is "stale", which is to say that either it is no longer open, or an attempt to read the connection would fail.

Unfortunately, due to the limitations of the JREs prior to 1.4, it is not possible to test a connection to see if both the read and write channels are open - except by reading and writing. This leads to a difficulty when some connections leave the "write" channel open, but close the read channel and ignore the request. This function attempts to ameliorate that problem by doing a test read, assuming that the caller will be doing a write followed by a read, rather than the other way around.

To avoid side-effects, the underlying connection is wrapped by a BufferedInputStream, so although data might be read, what is visible to clients of the connection will not change with this call.

Returns:

true if the connection is already closed, or a read would fail.

Throws:

IOException - if the stale connection test is interrupted.

isProxied

public boolean isProxied()

Returns true if the connection is established via a proxy, false otherwise.

Returns:

true if a proxy is used to establish the connection, false otherwise.

setLastResponseInputStream

public void setLastResponseInputStream(InputStream inStream)

Set the state to keep track of the last response for the last request.

The connection managers use this to ensure that previous requests are properly closed before a new request is attempted. That way, a GET request need not be read in its entirety before a new request is issued. Instead, this stream can be closed as appropriate.

Parameters:

inStream - The stream associated with an HttpMethod.

getLastResponseInputStream

public InputStream getLastResponseInputStream()

Returns the stream used to read the last response's body.

Clients will generally not need to call this function unless using HttpConnection directly, instead of calling HttpClient.executeMethod(HttpMethod). For those clients, call this function, and if it returns a non-null stream, close the stream before attempting to execute a method. Note that calling "close" on the stream returned by this function may close the connection if the previous response contained a "Connection: close" header.

Returns:

An InputStream corresponding to the body of the last response.

getParams

public HttpConnectionParams getParams()

Returns HTTP protocol parameters associated with this method.

Returns:

HTTP parameters.

Since:

3.0

setParams

public void setParams(HttpConnectionParams params)

Assigns HTTP protocol parameters for this method.

Parameters:

params - params to set. Cannot be null

Since:

3.0

See Also:

HttpConnectionParams

setSocketTimeout

public void setSocketTimeout(int timeout)
                      throws SocketException,
                             IllegalStateException

Sets SO_TIMEOUT value directly on the underlying socket. This method does not change the default read timeout value set via HttpConnectionParams.

Parameters:

timeout - the timeout value

Throws:

SocketException - - if there is an error in the underlying protocol, such as a TCP error.

IllegalStateException - if not connected

Since:

3.0

setFilter

public void setFilter(WireLogInputStream in,
                      org.apache.commons.httpclient.WireLogOutputStream out)

Set the input and out filter to use. Takes effect on the next open request.

Parameters:

in - the input filter to use. Set to null to disable filtering the input.

out - the output filter to use. Set to null to disable filtering the output.

open

public void open()
          throws IOException

Establishes a connection to the specified host and port (via a proxy if specified). The underlying socket is created from the ProtocolSocketFactory.

Throws:

IOException - if an attempt to establish the connection results in an I/O error.

tunnelCreated

public void tunnelCreated()
                   throws IllegalStateException,
                          IOException

Instructs the proxy to establish a secure tunnel to the host. The socket will be switched to the secure socket. Subsequent communication is done via the secure socket. The method can only be called once on a proxied secure connection.

Throws:

IllegalStateException - if connection is not secure and proxied or if the socket is already secure.

IOException - if an attempt to establish the secure tunnel results in an I/O error.

isTransparent

public boolean isTransparent()

Indicates if the connection is completely transparent from end to end.

Returns:

true if conncetion is not proxied or tunneled through a transparent proxy; false otherwise.

flushRequestOutputStream

public void flushRequestOutputStream()
                              throws IOException

Flushes the output request stream. This method should be called to ensure that data written to the request OutputStream is sent to the server.

Throws:

IOException - if an I/O problem occurs

getRequestOutputStream

public OutputStream getRequestOutputStream()
                                    throws IllegalStateException

Returns an OutputStream suitable for writing the request.

Returns:

a stream to write the request to

Throws:

IllegalStateException - if the connection is not open

getResponseInputStream

public InputStream getResponseInputStream()
                                   throws IllegalStateException

Return a InputStream suitable for reading the response.

Returns:

InputStream The response input stream.

Throws:

IllegalStateException - If the connection isn't open.

isResponseAvailable

public boolean isResponseAvailable()
                            throws IOException

Tests if input data avaialble. This method returns immediately and does not perform any read operations on the input socket

Returns:

boolean true if input data is available, false otherwise.

Throws:

IOException - If an IO problem occurs

IllegalStateException - If the connection isn't open.

isResponseAvailable

public boolean isResponseAvailable(int timeout)
                            throws IOException

Tests if input data becomes available within the given period time in milliseconds.

Parameters:

timeout - The number milliseconds to wait for input data to become available

Returns:

boolean true if input data is availble, false otherwise.

Throws:

IOException - If an IO problem occurs

IllegalStateException - If the connection isn't open.

write

public void write(byte[] data)
           throws IOException,
                  IllegalStateException

Writes the specified bytes to the output stream.

Parameters:

data - the data to be written

Throws:

IllegalStateException - if not connected

IOException - if an I/O problem occurs

See Also:

write(byte[],int,int)

write

public void write(byte[] data,
                  int offset,
                  int length)
           throws IOException,
                  IllegalStateException

Writes length bytes in data starting at offset to the output stream. The general contract for write(b, off, len) is that some of the bytes in the array b are written to the output stream in order; element b[off] is the first byte written and b[off+len-1] is the last byte written by this operation.

Parameters:

data - array containing the data to be written.

offset - the start offset in the data.

length - the number of bytes to write.

Throws:

IllegalStateException - if not connected

IOException - if an I/O problem occurs

writeLine

public void writeLine(byte[] data)
               throws IOException,
                      IllegalStateException

Writes the specified bytes, followed by "\r\n".getBytes() to the output stream.

Parameters:

data - the bytes to be written

Throws:

IllegalStateException - if the connection is not open

IOException - if an I/O problem occurs

writeLine

public void writeLine()
               throws IOException,
                      IllegalStateException

Writes "\r\n".getBytes() to the output stream.

Throws:

IllegalStateException - if the connection is not open

IOException - if an I/O problem occurs

print

public void print(String data,
                  String charset)
           throws IOException,
                  IllegalStateException

Writes the specified String (as bytes) to the output stream.

Parameters:

data - the string to be written

charset - the charset to use for writing the data

Throws:

IllegalStateException - if the connection is not open

IOException - if an I/O problem occurs

Since:

3.0

printLine

public void printLine(String data,
                      String charset)
               throws IOException,
                      IllegalStateException

Writes the specified String (as bytes), followed by "\r\n".getBytes() to the output stream.

Parameters:

data - the data to be written

charset - the charset to use for writing the data

Throws:

IllegalStateException - if the connection is not open

IOException - if an I/O problem occurs

Since:

3.0

printLine

public void printLine()
               throws IOException,
                      IllegalStateException

Writes "\r\n".getBytes() to the output stream.

Throws:

IllegalStateException - if the connection is not open

IOException - if an I/O problem occurs

readLine

public String readLine(String charset)
                throws IOException,
                       IllegalStateException

Reads up to "\n" from the (unchunked) input stream. If the stream ends before the line terminator is found, the last part of the string will still be returned.

Parameters:

charset - the charset to use for reading the data

Returns:

a line from the response

Throws:

IllegalStateException - if the connection is not open

IOException - if an I/O problem occurs

Since:

3.0

close

public void close()

Closes the socket and streams.

getHttpConnectionManager

public HttpConnectionManager getHttpConnectionManager()

Returns the httpConnectionManager.

Returns:

HttpConnectionManager

setHttpConnectionManager

public void setHttpConnectionManager(HttpConnectionManager httpConnectionManager)

Sets the httpConnectionManager.

Parameters:

httpConnectionManager - The httpConnectionManager to set

releaseConnection

public void releaseConnection()

Releases the connection. If the connection is locked or does not have a connection manager associated with it, this method has no effect. Note that it is completely safe to call this method multiple times.

isLocked

protected boolean isLocked()

Tests if the connection is locked. Locked connections cannot be released. An attempt to release a locked connection will have no effect.

Returns:

true if the connection is locked, false otherwise.

Since:

3.0

setLocked

protected void setLocked(boolean locked)

Locks or unlocks the connection. Locked connections cannot be released. An attempt to release a locked connection will have no effect.

Parameters:

locked - true to lock the connection, false to unlock the connection.

Since:

3.0

closeSocketAndStreams

protected void closeSocketAndStreams()

Closes everything out.

assertNotOpen

protected final void assertNotOpen()
                            throws IllegalStateException

Throws an IllegalStateException if the connection is already open.

Throws:

IllegalStateException - if connected

assertOpen

protected final void assertOpen()
                         throws IllegalStateException

Throws an IllegalStateException if the connection is not open.

Throws:

IllegalStateException - if not connected

getSendBufferSize

public int getSendBufferSize()
                      throws SocketException

Gets the socket's sendBufferSize.

Returns:

the size of the buffer for the socket OutputStream, -1 if the value has not been set and the socket has not been opened

Throws:

SocketException - if an error occurs while getting the socket value

See Also:

Socket.getSendBufferSize()