org.eclipse.jetty.servlets

Class ProxyServlet

java.lang.Object

org.eclipse.jetty.servlets.ProxyServlet

All Implemented Interfaces:

Servlet

Direct Known Subclasses:

BalancerServlet, ProxyServlet.Transparent

public class ProxyServlet
extends Object
implements Servlet

Asynchronous Proxy Servlet. Forward requests to another server either as a standard web proxy (as defined by RFC2616) or as a transparent proxy.

This servlet needs the jetty-util and jetty-client classes to be available to the web application.

To facilitate JMX monitoring, the "HttpClient" and "ThreadPool" are set as context attributes prefixed with the servlet name.

The following init parameters may be used to configure the servlet:

• name - Name of Proxy servlet (default: "ProxyServlet"
• maxThreads - maximum threads
• maxConnections - maximum connections per destination
• timeout - the period in ms the client will wait for a response from the proxied server
• idleTimeout - the period in ms a connection to proxied server can be idle for before it is closed
• requestHeaderSize - the size of the request header buffer (d. 6,144)
• requestBufferSize - the size of the request buffer (d. 12,288)
• responseHeaderSize - the size of the response header buffer (d. 6,144)
• responseBufferSize - the size of the response buffer (d. 32,768)
• HostHeader - Force the host header to a particular value
• whiteList - comma-separated list of allowed proxy destinations
• blackList - comma-separated list of forbidden proxy destinations

See Also:

ConnectHandler

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ProxyServlet.Transparent Transparent Proxy.

Field Summary

Fields

Modifier and Type	Field and Description
protected HostMap<PathMap>	_black
protected HttpClient	_client
protected ServletConfig	_config
protected ServletContext	_context
protected HashSet<String>	_DontProxyHeaders
protected String	_hostHeader
protected Logger	_log
protected HostMap<PathMap>	_white

Constructor Summary

Constructors

Constructor and Description
ProxyServlet()

Method Summary

Methods

Modifier and Type	Method and Description
protected HttpClient	createHttpClient(ServletConfig config) Create and return an HttpClient based on ServletConfig By default this implementation will create an instance of the HttpClient for use by this proxy servlet.
protected HttpClient	createHttpClientInstance() Create and return an HttpClientInstance
protected Logger	createLogger(ServletConfig config) Create and return a logger based on the ServletConfig for use in the proxy servlet
protected void	customizeContinuation(Continuation continuation) Extension point for subclasses to customize the Continuation after it's initial creation in the service method.
protected void	customizeExchange(HttpExchange exchange, HttpServletRequest request) Extension point for subclasses to customize an exchange.
void	destroy()
protected String	filterResponseHeaderValue(String headerName, String headerValue, HttpServletRequest request) Extension point for remote server response header filtering.
String	getHostHeader() Get the hostHeader.
ServletConfig	getServletConfig()
String	getServletInfo()
void	handleConnect(HttpServletRequest request, HttpServletResponse response)
protected void	handleOnConnectionFailed(Throwable ex, HttpServletRequest request, HttpServletResponse response) Extension point for custom handling of an HttpExchange's onConnectionFailed method.
protected void	handleOnException(Throwable ex, HttpServletRequest request, HttpServletResponse response) Extension point for custom handling of an HttpExchange's onException method.
protected void	handleOnExpire(HttpServletRequest request, HttpServletResponse response) Extension point for custom handling of an HttpExchange's onExpire method.
void	init(ServletConfig config)
protected HttpURI	proxyHttpURI(HttpServletRequest request, String uri)
protected HttpURI	proxyHttpURI(String scheme, String serverName, int serverPort, String uri)
void	service(ServletRequest req, ServletResponse res)
void	setHostHeader(String hostHeader) Set the hostHeader.
boolean	validateDestination(String host, String path) Check the request hostname and path against white- and blacklist.

Methods inherited from class java.lang.Object

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

Field Detail

_log

protected Logger _log

_client

protected HttpClient _client

_hostHeader

protected String _hostHeader

_DontProxyHeaders

protected HashSet<String> _DontProxyHeaders

_config

protected ServletConfig _config

_context

protected ServletContext _context

_white

protected HostMap<PathMap> _white

_black

protected HostMap<PathMap> _black

Constructor Detail

ProxyServlet

public ProxyServlet()

Method Detail

init

public void init(ServletConfig config)
          throws ServletException

Specified by:

init in interface Servlet

Throws:

ServletException

destroy

public void destroy()

Specified by:

destroy in interface Servlet

createLogger

protected Logger createLogger(ServletConfig config)

Create and return a logger based on the ServletConfig for use in the proxy servlet

Parameters:

config -

Returns:

Logger

createHttpClientInstance

protected HttpClient createHttpClientInstance()

Create and return an HttpClientInstance

Returns:

HttpClient

createHttpClient

protected HttpClient createHttpClient(ServletConfig config)
                               throws Exception

Create and return an HttpClient based on ServletConfig By default this implementation will create an instance of the HttpClient for use by this proxy servlet.

Parameters:

config -

Returns:

HttpClient

Throws:

Exception

validateDestination

public boolean validateDestination(String host,
                          String path)

Check the request hostname and path against white- and blacklist.

Parameters:

host - hostname to check

path - path to check

Returns:

true if request is allowed to be proxied

getServletConfig

public ServletConfig getServletConfig()

Specified by:

getServletConfig in interface Servlet

getHostHeader

public String getHostHeader()

Get the hostHeader.

Returns:

the hostHeader

setHostHeader

public void setHostHeader(String hostHeader)

Set the hostHeader.

Parameters:

hostHeader - the hostHeader to set

service

public void service(ServletRequest req,
           ServletResponse res)
             throws ServletException,
                    IOException

Specified by:

service in interface Servlet

Throws:

ServletException

IOException

handleConnect

public void handleConnect(HttpServletRequest request,
                 HttpServletResponse response)
                   throws IOException

Throws:

IOException

proxyHttpURI

protected HttpURI proxyHttpURI(HttpServletRequest request,
                   String uri)
                        throws MalformedURLException

Throws:

MalformedURLException

proxyHttpURI

protected HttpURI proxyHttpURI(String scheme,
                   String serverName,
                   int serverPort,
                   String uri)
                        throws MalformedURLException

Throws:

MalformedURLException

getServletInfo

public String getServletInfo()

Specified by:

getServletInfo in interface Servlet

customizeExchange

protected void customizeExchange(HttpExchange exchange,
                     HttpServletRequest request)

Extension point for subclasses to customize an exchange. Useful for setting timeouts etc. The default implementation does nothing.

Parameters:

exchange -

request -

customizeContinuation

protected void customizeContinuation(Continuation continuation)

Extension point for subclasses to customize the Continuation after it's initial creation in the service method. Useful for setting timeouts etc. The default implementation does nothing.

Parameters:

continuation -

handleOnConnectionFailed

protected void handleOnConnectionFailed(Throwable ex,
                            HttpServletRequest request,
                            HttpServletResponse response)

Extension point for custom handling of an HttpExchange's onConnectionFailed method. The default implementation delegates to handleOnException(Throwable, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)

Parameters:

ex -

request -

response -

handleOnException

protected void handleOnException(Throwable ex,
                     HttpServletRequest request,
                     HttpServletResponse response)

Extension point for custom handling of an HttpExchange's onException method. The default implementation sets the response status to HttpServletResponse.SC_INTERNAL_SERVER_ERROR (503)

Parameters:

ex -

request -

response -

handleOnExpire

protected void handleOnExpire(HttpServletRequest request,
                  HttpServletResponse response)

Extension point for custom handling of an HttpExchange's onExpire method. The default implementation sets the response status to HttpServletResponse.SC_GATEWAY_TIMEOUT (504)

Parameters:

request -

response -

filterResponseHeaderValue

protected String filterResponseHeaderValue(String headerName,
                               String headerValue,
                               HttpServletRequest request)

Extension point for remote server response header filtering. The default implementation returns the header value as is. If null is returned, this header won't be forwarded back to the client.

Parameters:

headerName -

headerValue -

request -

Returns:

filteredHeaderValue