org.eclipse.jetty.proxy

Class ProxyServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

org.eclipse.jetty.proxy.ProxyServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

Direct Known Subclasses:

BalancerServlet, ProxyServlet.Transparent

public class ProxyServlet
extends javax.servlet.http.HttpServlet

Asynchronous ProxyServlet.

Forwards requests to another server either as a standard web reverse proxy (as defined by RFC2616) or as a transparent reverse proxy.

To facilitate JMX monitoring, the HttpClient instance is set as context attribute, prefixed with the servlet's name and exposed by the mechanism provided by ContextHandler.MANAGED_ATTRIBUTES.

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

• hostHeader - forces the host header to a particular value
• viaHost - the name to use in the Via header: Via: http/1.1 <viaHost>
• whiteList - comma-separated list of allowed proxy hosts
• blackList - comma-separated list of forbidden proxy hosts

In addition, see createHttpClient() for init parameters used to configure the HttpClient instance.

See Also:

ConnectHandler, Serialized Form

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 Logger	_log
protected static String	ASYNC_CONTEXT

Constructor Summary

Constructors

Constructor and Description
ProxyServlet()

Method Summary

Methods

Modifier and Type	Method and Description
protected HttpClient	createHttpClient() Creates a HttpClient instance, configured with init parameters of this servlet.
protected Logger	createLogger()
protected void	customizeProxyRequest(Request proxyRequest, javax.servlet.http.HttpServletRequest request) Extension point for subclasses to customize the proxy request.
void	destroy()
protected String	filterResponseHeader(javax.servlet.http.HttpServletRequest request, String headerName, String headerValue) Extension point for remote server response header filtering.
Set<String>	getBlackListHosts()
protected int	getRequestId(javax.servlet.http.HttpServletRequest request)
long	getTimeout()
Set<String>	getWhiteListHosts()
void	init()
protected HttpClient	newHttpClient()
protected void	onResponseContent(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Response proxyResponse, byte[] buffer, int offset, int length)
protected void	onResponseFailure(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Response proxyResponse, Throwable failure)
protected void	onResponseHeaders(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Response proxyResponse)
protected void	onResponseSuccess(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Response proxyResponse)
protected URI	rewriteURI(javax.servlet.http.HttpServletRequest request)
protected void	service(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
void	setTimeout(long timeout)
boolean	validateDestination(String host, int port) Checks the given host and port against whitelist and blacklist.
protected static String	viaHost()

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service

Methods inherited from class javax.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

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

Field Detail

ASYNC_CONTEXT

protected static final String ASYNC_CONTEXT

_log

protected Logger _log

Constructor Detail

ProxyServlet

public ProxyServlet()

Method Detail

init

public void init()
          throws javax.servlet.ServletException

Overrides:

init in class javax.servlet.GenericServlet

Throws:

javax.servlet.ServletException

getTimeout

public long getTimeout()

setTimeout

public void setTimeout(long timeout)

getWhiteListHosts

public Set<String> getWhiteListHosts()

getBlackListHosts

public Set<String> getBlackListHosts()

viaHost

protected static String viaHost()

createLogger

protected Logger createLogger()

Returns:

a logger instance with a name derived from this servlet's name.

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Servlet

Overrides:

destroy in class javax.servlet.GenericServlet

createHttpClient

protected HttpClient createHttpClient()
                               throws javax.servlet.ServletException

Creates a HttpClient instance, configured with init parameters of this servlet.

The init parameters used to configure the HttpClient instance are:

init-param	default	description
maxThreads	256	The max number of threads of HttpClient's Executor
maxConnections	32768	The max number of connections per destination, see HttpClient.setMaxConnectionsPerDestination(int)
idleTimeout	30000	The idle timeout in milliseconds, see HttpClient.setIdleTimeout(long)
timeout	60000	The total timeout in milliseconds, see Request.timeout(long, TimeUnit)
requestBufferSize	HttpClient's default	The request buffer size, see HttpClient.setRequestBufferSize(int)
responseBufferSize	HttpClient's default	The response buffer size, see HttpClient.setResponseBufferSize(int)

Returns:

a HttpClient configured from the servlet configuration

Throws:

javax.servlet.ServletException - if the HttpClient cannot be created

newHttpClient

protected HttpClient newHttpClient()

Returns:

a new HttpClient instance

validateDestination

public boolean validateDestination(String host,
                          int port)

Checks the given host and port against whitelist and blacklist.

Parameters:

host - the host to check

port - the port to check

Returns:

true if it is allowed to be proxy to the given host and port

service

protected void service(javax.servlet.http.HttpServletRequest request,
           javax.servlet.http.HttpServletResponse response)
                throws javax.servlet.ServletException,
                       IOException

Overrides:

service in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

onResponseHeaders

protected void onResponseHeaders(javax.servlet.http.HttpServletRequest request,
                     javax.servlet.http.HttpServletResponse response,
                     Response proxyResponse)

onResponseContent

protected void onResponseContent(javax.servlet.http.HttpServletRequest request,
                     javax.servlet.http.HttpServletResponse response,
                     Response proxyResponse,
                     byte[] buffer,
                     int offset,
                     int length)
                          throws IOException

Throws:

IOException

onResponseSuccess

protected void onResponseSuccess(javax.servlet.http.HttpServletRequest request,
                     javax.servlet.http.HttpServletResponse response,
                     Response proxyResponse)

onResponseFailure

protected void onResponseFailure(javax.servlet.http.HttpServletRequest request,
                     javax.servlet.http.HttpServletResponse response,
                     Response proxyResponse,
                     Throwable failure)

getRequestId

protected int getRequestId(javax.servlet.http.HttpServletRequest request)

rewriteURI

protected URI rewriteURI(javax.servlet.http.HttpServletRequest request)

customizeProxyRequest

protected void customizeProxyRequest(Request proxyRequest,
                         javax.servlet.http.HttpServletRequest request)

Extension point for subclasses to customize the proxy request. The default implementation does nothing.

Parameters:

proxyRequest - the proxy request to customize

request - the request to be proxied

filterResponseHeader

protected String filterResponseHeader(javax.servlet.http.HttpServletRequest request,
                          String headerName,
                          String headerValue)

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 - the header name

headerValue - the header value

request - the request to proxy

Returns:

filteredHeaderValue the new header value