dk.heick.properties.derived.generics

Class KeyValuesFromTextFile

java.lang.Object

dk.heick.properties.derived.generics.KeyValuesFromTextFile

All Implemented Interfaces:

TypeFromGeneric<File,Hashtable<String,List<String>>>

public class KeyValuesFromTextFile
extends Object
implements TypeFromGeneric<File,Hashtable<String,List<String>>>

Reads a multi valued properties file.
For each key there can be many values, it is returned in Hashtable<String,List<String>>.
This is used by me as a quick solution to read data from text files.
Reads each line with the following rules:

• If line is empty, it is ignored.
• If line starts with comment indicator, it is ignored.
• The "key" and "value" is divide by the "KEY_VALUE_DIVIDER"
• The "key" must be a none empty string.
• The value can be a string with zero length.

Example:

 
 #ignored
 key1=value1
 key1=value2
 #ignored
 key1=value3
 key2=value4
 key3=value5
 key3=value6
 #ignored
 

Since:

2.0

Author:

Frederik Heick

See Also:

MapUtils

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_COMMENT_INDICATOR The default comment indicator, "#", if the line starts with this, it is ignored.
static String	DEFAULT_KEY_VALUE_DIVIDER The default key/value divider "="

Constructor Summary

Constructors

Constructor and Description
KeyValuesFromTextFile() Default constructor, using DEFAULT_KEY_VALUE_DIVIDER and DEFAULT_COMMENT_INDICATOR.
KeyValuesFromTextFile(String keyValueDivider, String commentIndicator) Constructor.

Method Summary

Modifier and Type	Method and Description
Hashtable<String,List<String>>	fromType(String propertyName, File from) The method which converts K to the type T.
String	getCommentIndicator() The string which indicates that a String is a comment, if it starts with this.
String	getKeyValueDivider() Returns the string which divides the key and value in a string.
org.apache.commons.logging.Log	getLogger() Gets a logger.
List<String>	getRestrictions() Gets a detailed description of the TypeFromGeneric with any constraints that might influence the validation.
String	getTypeName() The simpel short name.
void	validateConstraints(String propertyName) Validates the constraints for the type.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_KEY_VALUE_DIVIDER

public static final String DEFAULT_KEY_VALUE_DIVIDER

The default key/value divider "="

See Also:

Constant Field Values

DEFAULT_COMMENT_INDICATOR

public static final String DEFAULT_COMMENT_INDICATOR

The default comment indicator, "#", if the line starts with this, it is ignored.

See Also:

Constant Field Values

Constructor Detail

KeyValuesFromTextFile

public KeyValuesFromTextFile()

Default constructor, using DEFAULT_KEY_VALUE_DIVIDER and DEFAULT_COMMENT_INDICATOR.

See Also:

DEFAULT_KEY_VALUE_DIVIDER, DEFAULT_COMMENT_INDICATOR

KeyValuesFromTextFile

public KeyValuesFromTextFile(String keyValueDivider,
                             String commentIndicator)

Constructor.

Parameters:

keyValueDivider - the key/value divider, must be a none empty string.

commentIndicator - the comment indicator, must be a none empty string.

Method Detail

getKeyValueDivider

public String getKeyValueDivider()

Returns the string which divides the key and value in a string.

Returns:

the keyValueDivider

getCommentIndicator

public String getCommentIndicator()

The string which indicates that a String is a comment, if it starts with this.

Returns:

the commentIndicator

fromType

public Hashtable<String,List<String>> fromType(String propertyName,
                                               File from)
                                        throws PropertyException

Description copied from interface: TypeFromGeneric

The method which converts K to the type T.

Specified by:

fromType in interface TypeFromGeneric<File,Hashtable<String,List<String>>>

Parameters:

propertyName - the name of the property, this is Derived Property, not the Property which supplies the import for the type conversion.

from - the type K

Returns:

to the type T

Throws:

PropertyException - if the conversion could not be performed.

getTypeName

public String getTypeName()

Description copied from interface: TypeFromGeneric

The simpel short name. as "PublicKey from File"

Specified by:

getTypeName in interface TypeFromGeneric<File,Hashtable<String,List<String>>>

Returns:

the short identifing type name.

validateConstraints

public void validateConstraints(String propertyName)
                         throws PropertyException

Description copied from interface: TypeFromGeneric

Validates the constraints for the type.

Specified by:

validateConstraints in interface TypeFromGeneric<File,Hashtable<String,List<String>>>

Parameters:

propertyName - the name of the property which validates the constraints, this is Derived Property, not the Property which supplies the import for the type conversion.

Throws:

PropertyException - if the constraints do not hold.

getRestrictions

public List<String> getRestrictions()

Description copied from interface: TypeFromGeneric

Gets a detailed description of the TypeFromGeneric with any constraints that might influence the validation.
This includes a description for the default value, if the default do not it self parse the validation of the type, the exception is appended to the description.
Do NOT need to include the Property it is dependent on, since DerivedFromTypePropertyType will ensure that this is included.

Specified by:

getRestrictions in interface TypeFromGeneric<File,Hashtable<String,List<String>>>

Returns:

the restictions as a list of Strings, please as unmodifiable.

See Also:

StringList, StringList.asUnmodifiableList()

getLogger

public org.apache.commons.logging.Log getLogger()

Description copied from interface: TypeFromGeneric

Gets a logger.

Specified by:

getLogger in interface TypeFromGeneric<File,Hashtable<String,List<String>>>

Returns:

a logger