org.apache.shiro.web.filter.mgt
Interface FilterChainManager

All Known Implementing Classes:
DefaultFilterChainManager

public interface FilterChainManager

A FilterChainManager manages the creation and modification of Filter chains from an available pool of Filter instances.

Since:
1.0

Method Summary
 void addFilter(String name, Filter filter)
          Adds a filter to the 'pool' of available filters that can be used when creating filter chains.
 void addFilter(String name, Filter filter, boolean init)
          Adds a filter to the 'pool' of available filters that can be used when creating filter chains.
 void addToChain(String chainName, String filterName)
          Adds (appends) a filter to the filter chain identified by the given chainName.
 void addToChain(String chainName, String filterName, String chainSpecificFilterConfig)
          Adds (appends) a filter to the filter chain identified by the given chainName.
 void createChain(String chainName, String chainDefinition)
          Creates a filter chain for the given chainName with the specified chainDefinition String.
 NamedFilterList getChain(String chainName)
          Returns the filter chain identified by the specified chainName or null if there is no chain with that name.
 Set<String> getChainNames()
          Returns the names of all configured chains or an empty Set if no chains have been configured.
 Map<String,Filter> getFilters()
          Returns the pool of available Filters managed by this manager, keyed by name.
 boolean hasChains()
          Returns true if one or more configured chains are available, false if none are configured.
 FilterChain proxy(FilterChain original, String chainName)
          Proxies the specified original FilterChain with the named chain.
 

Method Detail

getFilters

Map<String,Filter> getFilters()
Returns the pool of available Filters managed by this manager, keyed by name.

Returns:
the pool of available Filters managed by this manager, keyed by name.

getChain

NamedFilterList getChain(String chainName)
Returns the filter chain identified by the specified chainName or null if there is no chain with that name.

Parameters:
chainName - the name identifying the filter chain.
Returns:
the filter chain identified by the specified chainName or null if there is no chain with that name.

hasChains

boolean hasChains()
Returns true if one or more configured chains are available, false if none are configured.

Returns:
true if one or more configured chains are available, false if none are configured.

getChainNames

Set<String> getChainNames()
Returns the names of all configured chains or an empty Set if no chains have been configured.

Returns:
the names of all configured chains or an empty Set if no chains have been configured.

proxy

FilterChain proxy(FilterChain original,
                  String chainName)
Proxies the specified original FilterChain with the named chain. The returned FilterChain instance will first execute the configured named chain and then lastly invoke the given original chain.

Parameters:
original - the original FilterChain to proxy
chainName - the name of the internal configured filter chain that should 'sit in front' of the specified original chain.
Returns:
a FilterChain instance that will execute the named chain and then finally the specified original FilterChain instance.
Throws:
IllegalArgumentException - if there is no configured chain with the given chainName.

addFilter

void addFilter(String name,
               Filter filter)
Adds a filter to the 'pool' of available filters that can be used when creating filter chains.

Calling this method is effectively the same as calling addFilter(name, filter, false);

Parameters:
name - the name to assign to the filter, used to reference the filter in chain definitions
filter - the filter to initialize and then add to the pool of available filters that can be used

addFilter

void addFilter(String name,
               Filter filter,
               boolean init)
Adds a filter to the 'pool' of available filters that can be used when creating filter chains.

Parameters:
name - the name to assign to the filter, used to reference the filter in chain definitions
filter - the filter to assign to the filter pool
init - whether or not the Filter should be initialized first before being added to the pool.

createChain

void createChain(String chainName,
                 String chainDefinition)
Creates a filter chain for the given chainName with the specified chainDefinition String.

Conventional Use

Because the FilterChainManager interface does not impose any restrictions on filter chain names, (it expects only Strings), a convenient convention is to make the chain name an actual URL path expression (such as an Ant path expression). For example:

createChain(path_expression, path_specific_filter_chain_definition); This convention can be used by a FilterChainResolver to inspect request URL paths against the chain name (path) and, if a match is found, return the corresponding chain for runtime filtering.

Chain Definition Format

The chainDefinition method argument is expected to conform to the following format:
 filter1[optional_config1], filter2[optional_config2], ..., filterN[optional_configN]
where
  1. filterN is the name of a filter previously registered with the manager, and
  2. [optional_configN] is an optional bracketed string that has meaning for that particular filter for this particular chain
If the filter does not need specific config for that chain name/URL path, you may discard the brackets - that is, filterN[] just becomes filterN.

And because this method does create a chain, remember that order matters! The comma-delimited filter tokens in the chainDefinition specify the chain's execution order.

Examples

/account/** = authcBasic
This example says "Create a filter named '/account/**' consisting of only the 'authcBasic' filter". Also because the authcBasic filter does not need any path-specific config, it doesn't have any config brackets [].

/remoting/** = authcBasic, roles[b2bClient], perms["remote:invoke:wan,lan"]
This example by contrast uses the 'roles' and 'perms' filters which do use bracket notation. This definition says:

Construct a filter chain named '/remoting/**' which

  1. ensures the user is first authenticated (authcBasic) then
  2. ensures that user has the b2bClient role, and then finally
  3. ensures that they have the remote:invoke:lan,wan permission.

Note: because elements within brackets [ ] can be comma-delimited themselves, you must quote the internal bracket definition if commas are needed (the above example has 'lan,wan'). If we didn't do that, the parser would interpret the chain definition as four tokens:

  1. authcBasic
  2. roles[b2bclient]
  3. perms[remote:invoke:lan
  4. wan]
which is obviously incorrect. So remember to use quotes if your internal bracket definitions need to use commas.

Parameters:
chainName - the name to associate with the chain, conventionally a URL path pattern.
chainDefinition - the string-formatted chain definition used to construct an actual NamedFilterList chain instance.
See Also:
FilterChainResolver, AntPathMatcher

addToChain

void addToChain(String chainName,
                String filterName)
Adds (appends) a filter to the filter chain identified by the given chainName. If there is no chain with the given name, a new one is created and the filter will be the first in the chain.

Parameters:
chainName - the name of the chain where the filter will be appended.
filterName - the name of the registered filter to add to the chain.
Throws:
IllegalArgumentException - if there is not a registered filter under the given filterName

addToChain

void addToChain(String chainName,
                String filterName,
                String chainSpecificFilterConfig)
                throws ConfigurationException
Adds (appends) a filter to the filter chain identified by the given chainName. If there is no chain with the given name, a new one is created and the filter will be the first in the chain.

Note that the final argument expects the associated filter to be an instance of a PathConfigProcessor to accept per-chain configuration. If it is not, a IllegalArgumentException will be thrown.

Parameters:
chainName - the name of the chain where the filter will be appended.
filterName - the name of the registered filter to add to the chain.
chainSpecificFilterConfig - the filter-specific configuration that should be applied for only the specified filter chain.
Throws:
IllegalArgumentException - if there is not a registered filter under the given filterName
ConfigurationException - if the filter is not capable of accepting chainSpecificFilterConfig (usually such filters implement the PathConfigProcessor interface).


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