Package org.apache.commons.chain.generic

Class LookupCommand

  • All Implemented Interfaces:
    Command, Filter
    Direct Known Subclasses:
    DispatchLookupCommand, PathInfoMapper, RequestParameterMapper, ServletPathMapper
    public class LookupCommand
extends java.lang.Object
implements Filter

    Look up a specified Command (which could also be a Chain) in a Catalog, and delegate execution to it. If the delegated-to Command is also a Filter, its postprocess() method will also be invoked at the appropriate time.

    The name of the Command can be specified either directly (via the name property) or indirectly (via the nameKey property). Exactly one of these must be set.

    If the optional property is set to true, failure to find the specified command in the specified catalog will be silently ignored. Otherwise, a lookup failure will trigger an IllegalArgumentException.

    Version:
    $Revision: 532951 $ $Date: 2007-04-27 04:59:00 +0100 (Fri, 27 Apr 2007) $
    Author:
    Craig R. McClanahan

    • Field Detail

      • catalogName

        private java.lang.String catalogName

      • name

        private java.lang.String name

      • nameKey

        private java.lang.String nameKey

      • optional

        private boolean optional

      • ignoreExecuteResult

        private boolean ignoreExecuteResult

      • ignorePostprocessResult

        private boolean ignorePostprocessResult

    • Constructor Detail

      • LookupCommand

        public LookupCommand()
        Create an instance, setting its catalogFactory property to the value of CatalogFactory.getInstance().
        Since:
        Chain 1.1

      • LookupCommand

        public LookupCommand​(CatalogFactory factory)
        Create an instance and initialize the catalogFactory property to given factory/
        Parameters:
        factory - The Catalog Factory.
        Since:
        Chain 1.1

    • Method Detail

      • setCatalogFactory

        public void setCatalogFactory​(CatalogFactory catalogFactory)

        Set the CatalogFactory from which lookups will be performed.

        Parameters:
        catalogFactory - The Catalog Factory.
        Since:
        Chain 1.1

      • getCatalogFactory

        public CatalogFactory getCatalogFactory()
        Return the CatalogFactory from which lookups will be performed.
        Returns:
        The Catalog factory.
        Since:
        Chain 1.1

      • getCatalogName

        public java.lang.String getCatalogName()

        Return the name of the Catalog to be searched, or null to search the default Catalog.

        Returns:
        The Catalog name.

      • setCatalogName

        public void setCatalogName​(java.lang.String catalogName)

        Set the name of the Catalog to be searched, or null to search the default Catalog.

        Parameters:
        catalogName - The new Catalog name or null

      • getName

        public java.lang.String getName()

        Return the name of the Command that we will look up and delegate execution to.

        Returns:
        The name of the Command.

      • setName

        public void setName​(java.lang.String name)

        Set the name of the Command that we will look up and delegate execution to.

        Parameters:
        name - The new command name

      • getNameKey

        public java.lang.String getNameKey()

        Return the context attribute key under which the Command name is stored.

        Returns:
        The context key of the Command.

      • setNameKey

        public void setNameKey​(java.lang.String nameKey)

        Set the context attribute key under which the Command name is stored.

        Parameters:
        nameKey - The new context attribute key

      • isOptional

        public boolean isOptional()

        Return true if locating the specified command is optional.

        Returns:
        true if the Command is optional.

      • setOptional

        public void setOptional​(boolean optional)

        Set the optional flag for finding the specified command.

        Parameters:
        optional - The new optional flag

      • isIgnoreExecuteResult

        public boolean isIgnoreExecuteResult()

        Return true if this command should ignore the return value from executing the looked-up command. Defaults to false, which means that the return result of executing this lookup will be whatever is returned from that command.

        Returns:
        true if result of the looked up Command should be ignored.
        Since:
        Chain 1.1

      • setIgnoreExecuteResult

        public void setIgnoreExecuteResult​(boolean ignoreReturn)

        Set the rules for whether or not this class will ignore or pass through the value returned from executing the looked up command.

        If you are looking up a chain which may be "aborted" and you do not want this class to stop chain processing, then this value should be set to true

        Parameters:
        ignoreReturn - true if result of the looked up Command should be ignored.
        Since:
        Chain 1.1

      • isIgnorePostprocessResult

        public boolean isIgnorePostprocessResult()

        Return true if this command is a Filter and should ignore the return value from executing the looked-up Filter's postprocess() method. Defaults to false, which means that the return result of executing this lookup will be whatever is returned from that Filter.

        Returns:
        true if result of the looked up Filter's postprocess() method should be ignored.
        Since:
        Chain 1.1

      • setIgnorePostprocessResult

        public void setIgnorePostprocessResult​(boolean ignorePostprocessResult)

        Set the rules for whether or not this class will ignore or pass through the value returned from executing the looked up Filter's postprocess() method.

        If you are looking up a Filter which may be "aborted" and you do not want this class to stop chain processing, then this value should be set to true

        Parameters:
        ignorePostprocessResult - true if result of the looked up Filter's postprocess() method should be ignored.
        Since:
        Chain 1.1

      • execute

        public boolean execute​(Context context)
                throws java.lang.Exception

        Look up the specified command, and (if found) execute it. Unless ignoreExecuteResult is set to true, return the result of executing the found command. If no command is found, return false, unless the optional property is false, in which case an IllegalArgumentException will be thrown.

        Specified by:
        execute in interface Command
        Parameters:
        context - The context for this request
        Returns:
        the result of executing the looked-up command, or false if no command is found or if the command is found but the ignoreExecuteResult property of this instance is true
        Throws:
        java.lang.IllegalArgumentException - if no such Command can be found and the optional property is set to false
        java.lang.Exception - if and error occurs in the looked-up Command.

      • postprocess

        public boolean postprocess​(Context context,
                           java.lang.Exception exception)

        If the executed command was itself a Filter, call the postprocess() method of that Filter as well.

        Specified by:
        postprocess in interface Filter
        Parameters:
        context - The context for this request
        exception - Any Exception thrown by command execution
        Returns:
        the result of executing the postprocess method of the looked-up command, unless ignorePostprocessResult is true. If no command is found, return false, unless the optional property is false, in which case IllegalArgumentException will be thrown.

      • getCatalog

        protected Catalog getCatalog​(Context context)

        Return the Catalog to look up the Command in.

        Parameters:
        context - Context for this request
        Returns:
        The catalog.
        Throws:
        java.lang.IllegalArgumentException - if no Catalog can be found
        Since:
        Chain 1.2

      • getCommand

        protected Command getCommand​(Context context)

        Return the Command instance to be delegated to.

        Parameters:
        context - Context for this request
        Returns:
        The looked-up Command.
        Throws:
        java.lang.IllegalArgumentException - if no such Command can be found and the optional property is set to false

      • getCommandName

        protected java.lang.String getCommandName​(Context context)

        Return the name of the Command instance to be delegated to.

        Parameters:
        context - Context for this request
        Returns:
        The name of the Command instance
        Since:
        Chain 1.2