com.amazonaws.serverless.proxy.internal.servlet

Class FilterChainManager<ServletContextType>

java.lang.Object

com.amazonaws.serverless.proxy.internal.servlet.FilterChainManager<ServletContextType>

Direct Known Subclasses:

AwsFilterChainManager

public abstract class FilterChainManager<ServletContextType>
extends java.lang.Object

This object in in charge of matching a servlet request to a set of filter, creating the filter chain for a request, and cache filter chains that were already loaded for re-use. This object should be used by the framework-specific implementations that use the HttpServletRequest and HttpServletResponse objects. For example, the Spring implementation creates the ServletContext when the application is initialized the first time and creates a FitlerChainManager to execute its filters for each request.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	FilterChainManager.TargetCacheKey Object used as a key for the filter chain cache.

Field Summary

Fields

Modifier and Type	Field and Description
protected static java.lang.String	PATH_PART_SEPARATOR
protected ServletContextType	servletContext

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FilterChainManager(ServletContextType context)

Method Summary

Modifier and Type	Method and Description
FilterChainHolder	getFilterChain(javax.servlet.http.HttpServletRequest request) Returns the filter chain that applies to the given request.
protected FilterChainHolder	getFilterChainCache(javax.servlet.DispatcherType type, java.lang.String targetPath) Retrieves a filter chain from the cache.
protected abstract java.util.Map<java.lang.String,FilterHolder>	getFilterHolders() This method is used by the getFilterChain method to extract a Map of filter holders from the current context.
protected boolean	pathMatches(java.lang.String target, java.lang.String mapping) Checks if a mapping path matches the target path of the request.
protected void	putFilterChainCache(javax.servlet.DispatcherType type, java.lang.String targetPath, FilterChainHolder holder) Adds a filter chain to the local cache.

Methods inherited from class java.lang.Object

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

Field Detail

PATH_PART_SEPARATOR

protected static final java.lang.String PATH_PART_SEPARATOR

See Also:

Constant Field Values

servletContext

protected ServletContextType servletContext

Constructor Detail

FilterChainManager

protected FilterChainManager(ServletContextType context)

Method Detail

getFilterHolders

protected abstract java.util.Map<java.lang.String,FilterHolder> getFilterHolders()

This method is used by the getFilterChain method to extract a Map of filter holders from the current context. This method is implemented in the AwsFilterChainManager class.

Returns:

A Map of filter holders with the filter name as key and the filter holder object as value

getFilterChain

public FilterChainHolder getFilterChain(javax.servlet.http.HttpServletRequest request)

Returns the filter chain that applies to the given request. The method matches requests to filters using the DispatcherType value (set to REQUEST by default in the AwsProxyHttpServletRequest) and the target path returned by the getPath method of the request. This method currently does not filter on servlet name because the library assumes we are using a single servlet.

Parameters:

request - The incoming servlet request

Returns:

A FilterChainHolder object that can be used to apply the filters to the request

getFilterChainCache

protected FilterChainHolder getFilterChainCache(javax.servlet.DispatcherType type,
                                                java.lang.String targetPath)

Retrieves a filter chain from the cache. The cache is lazily loaded as filter chains are requested. If the chain is not available in the cache, the method returns null.

Parameters:

type - The dispatcher type for the incoming request

targetPath - The request path - this is extracted with the getPath method of the request object

Returns:

A populated FilterChainHolder

putFilterChainCache

protected void putFilterChainCache(javax.servlet.DispatcherType type,
                                   java.lang.String targetPath,
                                   FilterChainHolder holder)

Adds a filter chain to the local cache. The key for the filter chain in the cache is generated with the dispatcher type and the path from the request. If we cannot compute the key for a filter chain, because either the path or dispatcher are null, this method returns without saving the chain in the cache. It's up to the getFilterChain method to retry this.

Parameters:

type - DispatcherType from the incoming request

targetPath - The target path in the API

holder - The FilterChainHolder object to save in the cache

pathMatches

protected boolean pathMatches(java.lang.String target,
                              java.lang.String mapping)

Checks if a mapping path matches the target path of the request. The mapping path can include wildcards. For example, the filter configured for /echo/* will match for request coming to all sub-resources of /echo. If not path

Parameters:

target - The target path from the incoming request

mapping - The mapping path stored in the filter registration

Returns:

true if the given mapping path can apply to the target, false otherwise.