com.programix.command
Class CommandProcessorFactory

java.lang.Object
  com.programix.command.CommandProcessorFactory

public class CommandProcessorFactory
extends Object

Used to construct and initialize instances of CommandProcessor using reflection.

Common usage is (where CustomerCommandProcessor is an interface that extends the CommandProcessor interface):

 ValueMap config = //...
 CustomerCommandProcessor ccp = (CustomerCommandProcessor) 
     CommandProcessorFactory.create(config, CustomerCommandProcessor.class);

or

 String filename = //...
 CustomerCommandProcessor cda = (CustomerCommandProcessor) 
     CommandProcessorFactory.create(filename, CustomerCommandProcessor.class);

The configuration ValueMap passed in must contain the class name of the class to be instantiated stored under the key COMMAND_PROCESSOR_CLASSNAME_KEY. Other key/value pairs in the map are populated with whatever the specific CommandProcessor implementation needs for initialization.

Author:

Paul Hyde

Field Summary

static String

COMMAND_PROCESSOR_CLASSNAME_KEY The reserved key that retrieves the fully-qualified name (as a String) of the CommandProcessor implementation class that will be instantiated via reflection.

Method Summary

static CommandProcessor	create(File file, Class targetType) Create a CommandProcessor instance using an File whose data is in the format described by ValueMap (nearly identical to the format for a Properties file).
static CommandProcessor	create(InputStream rawIn, Class targetType) Create a CommandProcessor instance using an InputStream whose data is in the format described by ValueMap (nearly identical to the format for a Properties file).
static CommandProcessor	create(Reader rawIn, Class targetType) Create a CommandProcessor instance using a Reader whose data is in the format described by ValueMap (nearly identical to the format for a Properties file).
static CommandProcessor	create(URL propertiesURL, Class targetType) Create a CommandProcessor instance using the specified URL whose data is in the format described by ValueMap(nearly identical to the format for a Properties file).
static CommandProcessor	create(ValueMap config, Class targetType) Constructs an instance of the CommandProcessor implementation specified in the configuration.
static CommandProcessor	createFromFile(String filename, Class targetType) Create a CommandProcessor instance using the specified filename whose data is in the format described by ValueMap(nearly identical to the format for a Properties file).
static CommandProcessor	createFromResource(String resourceLocation, Class targetType) Create a CommandProcessor instance using the specified resourceLocation whose data is in the format described by ValueMap(nearly identical to the format for a Properties file).

Methods inherited from class java.lang.Object

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

Field Detail

COMMAND_PROCESSOR_CLASSNAME_KEY

public static final String COMMAND_PROCESSOR_CLASSNAME_KEY

The reserved key that retrieves the fully-qualified name (as a String) of the CommandProcessor implementation class that will be instantiated via reflection.

The value of this key is always:

 command.processor.classname
 

See Also:

Constant Field Values

Method Detail

create

public static CommandProcessor create(ValueMap config,
                                      Class targetType)
                               throws CommandException

Constructs an instance of the CommandProcessor implementation specified in the configuration. One required key that must always be present is: COMMAND_PROCESSOR_CLASSNAME_KEY with a String value which is the full class name.

Immediately after the zero-argument constructor is invoked, the init(ValueMap conf) of CommandProcessor is invoked to initialize the configuration.

If the targetType is not null, then an additional check is done to ensure that the constructed object can be type cast into that type (failures throw a CommandException instead of a ClassCastException).

Parameters:

config - key/value mapping with everything that is needed to initialize the instance of CommandProcessor.

targetType - the class type that this instance is expected to be cast into. Use null to skip this check. If not null and the type does not match what is constructed, then a CommandException is thrown.

Returns:

the constructed and initialized instance.

Throws:

CommandException - if instance can not be constructed and initialized.

See Also:

create(Reader, Class), create(InputStream, Class), createFromFile(String, Class), create(File, Class), create(URL, Class)

create

public static CommandProcessor create(Reader rawIn,
                                      Class targetType)
                               throws CommandException

Create a CommandProcessor instance using a Reader whose data is in the format described by ValueMap (nearly identical to the format for a Properties file). Internally, the stream will be buffered and the stream will be closed.

Parameters:

rawIn - a stream whose contents can be loaded into a ValueMap with everything that is needed to initialize the instance of CommandProcessor.

targetType - the class type that this instance is expected to be cast into. Use null to skip this check. If not null and the type does not match what is constructed, then a CommandException is thrown.

Returns:

the constructed and initialized instance.

Throws:

CommandException - if instance can not be constructed and initialized.

See Also:

create(ValueMap, Class), create(InputStream, Class), createFromFile(String, Class), create(File, Class), create(URL, Class)

create

public static CommandProcessor create(InputStream rawIn,
                                      Class targetType)
                               throws CommandException

Create a CommandProcessor instance using an InputStream whose data is in the format described by ValueMap (nearly identical to the format for a Properties file). Internally, the stream will be buffered and the stream will be closed.

Parameters:

rawIn - a stream whose contents can be loaded into a ValueMap with everything that is needed to initialize the instance of CommandProcessor.

targetType - the class type that this instance is expected to be cast into. Use null to skip this check. If not null and the type does not match what is constructed, then a CommandException is thrown.

Returns:

the constructed and initialized instance.

Throws:

CommandException - if instance can not be constructed and initialized.

See Also:

create(ValueMap, Class), create(Reader, Class), createFromFile(String, Class), create(File, Class), create(URL, Class)

create

public static CommandProcessor create(File file,
                                      Class targetType)
                               throws CommandException

Create a CommandProcessor instance using an File whose data is in the format described by ValueMap (nearly identical to the format for a Properties file).

Parameters:

file - file with key/value mapping with everything that is needed to initialize the instance of CommandProcessor.

targetType - the class type that this instance is expected to be cast into. Use null to skip this check. If not null and the type does not match what is constructed, then a CommandException is thrown.

Returns:

the constructed and initialized instance.

Throws:

CommandException - if instance can not be constructed and initialized.

See Also:

create(ValueMap, Class), create(Reader, Class), create(InputStream, Class), createFromFile(String, Class), create(URL, Class)

createFromFile

public static CommandProcessor createFromFile(String filename,
                                              Class targetType)
                                       throws CommandException

Create a CommandProcessor instance using the specified filename whose data is in the format described by ValueMap(nearly identical to the format for a Properties file).

Parameters:

filename - file with key/value mapping with everything that is needed to initialize the instance of CommandProcessor.

targetType - the class type that this instance is expected to be cast into. Use null to skip this check. If not null and the type does not match what is constructed, then a CommandException is thrown.

Returns:

the constructed and initialized instance.

Throws:

CommandException - if instance can not be constructed and initialized.

See Also:

create(ValueMap, Class), create(Reader, Class), create(InputStream, Class), create(File, Class), create(URL, Class)

create

public static CommandProcessor create(URL propertiesURL,
                                      Class targetType)
                               throws CommandException

Create a CommandProcessor instance using the specified URL whose data is in the format described by ValueMap(nearly identical to the format for a Properties file).

Parameters:

propertiesURL - a URL whose contents can be loaded into a ValueMap with everything that is needed to initialize the instance of CommandProcessor.

targetType - the class type that this instance is expected to be cast into. Use null to skip this check. If not null and the type does not match what is constructed, then a CommandException is thrown.

Returns:

the constructed and initialized instance.

Throws:

CommandException - if instance can not be constructed and initialized.

See Also:

create(ValueMap, Class), create(Reader, Class), create(InputStream, Class), createFromFile(String, Class), create(File, Class), createFromResource(String, Class)

createFromResource

public static CommandProcessor createFromResource(String resourceLocation,
                                                  Class targetType)
                                           throws CommandException

Create a CommandProcessor instance using the specified resourceLocation whose data is in the format described by ValueMap(nearly identical to the format for a Properties file).

Parameters:

resourceLocation - file with key/value mapping with everything that is needed to initialize the instance of CommandProcessor.

targetType - the class type that this instance is expected to be cast into. Use null to skip this check. If not null and the type does not match what is constructed, then a CommandException is thrown.

Returns:

the constructed and initialized instance.

Throws:

CommandException - if instance can not be constructed and initialized.

See Also:

create(ValueMap, Class), create(Reader, Class), create(InputStream, Class), create(File, Class), createFromFile(String, Class), create(URL, Class)