org.rapidcontext.core.data

Class PropertiesSerializer

java.lang.Object

org.rapidcontext.core.data.PropertiesSerializer

public class PropertiesSerializer
extends java.lang.Object

A dictionary serializer and unserializer for the standard Java properties file format. The dictionary mapping to the properties format is not exact, and may omit serialization of data in some cases. The following basic requirements must be met in order to serialize a dictionary into a properties file:

• No circular references are permitted.
• String, Integer, Boolean, Array and Dict objects are supported.
• Other object types are converted to strings with toString().
• Property key names must consist only of printable ISO-8859-1 character, without any spaces or dots.
• Property key names should never consist of only numeric characters, since they will then be confused with array indices.
• Array null values will be omitted, renumbering the remaining indices.

The structure and order of dictionary objects will be kept, using the file order in the properties file and dot-notation for property names.

Version:

1.0

Author:

Per Cederberg

Constructor Summary

Constructors

Constructor and Description
PropertiesSerializer()

Method Summary

Modifier and Type	Method and Description
static Dict	read(java.io.File file) Reads a file containing properties and returns the contents in a dictionary.
static Dict	read(java.util.zip.ZipFile zip, java.util.zip.ZipEntry entry) Reads a ZIP file entry containing properties and returns the contents in a dictionary.
static java.lang.String	serialize(java.lang.Object obj) Serializes an object into an properties representation.
static java.util.Properties	toProperties(Dict dict) Converts a dictionary into a properties object.
static void	write(java.io.File file, Dict dict) Writes the contents of a dictionary into a properties file.

Methods inherited from class java.lang.Object

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

Constructor Detail

PropertiesSerializer

public PropertiesSerializer()

Method Detail

serialize

public static java.lang.String serialize(java.lang.Object obj)
                                  throws java.io.IOException

Serializes an object into an properties representation. The string returned can be used as a properties.

Parameters:

obj - the object to convert, or null

Returns:

an properties file representation

Throws:

java.io.IOException - if the data couldn't be serialized

read

public static Dict read(java.io.File file)
                 throws java.io.FileNotFoundException,
                        java.io.IOException

Reads a file containing properties and returns the contents in a dictionary. The property names from the file are normally preserved, except for structural interpretation. Dot ('.') characters in names are interpreted as sub-object separators, and numbers are interpreted as an array indices. The dictionary values are stored as booleans, integers or strings.

Parameters:

file - the file to load

Returns:

the dictionary read from the file

Throws:

java.io.FileNotFoundException - if the file couldn't be found

java.io.IOException - if an error occurred while reading the file

read

public static Dict read(java.util.zip.ZipFile zip,
                        java.util.zip.ZipEntry entry)
                 throws java.io.IOException

Reads a ZIP file entry containing properties and returns the contents in a dictionary. The property names from the file are normally preserved, except for structural interpretation. Dot ('.') characters in names are interpreted as sub-object separators, and numbers are interpreted as an array indices. The dictionary values are stored as booleans, integers or strings.

Parameters:

zip - the ZIP file

entry - the ZIP file entry to load

Returns:

the dictionary read from the file

Throws:

java.io.IOException - if an error occurred while reading the file

write

public static void write(java.io.File file,
                         Dict dict)
                  throws java.io.IOException

Writes the contents of a dictionary into a properties file. The key names from the dictionary are preserved, but contained array indices will be renumbered from zero while omitting null values. Contained dictionary or array values will be written recursively by appending dot ('.') characters between each element. All other values are stored as strings.

Parameters:

file - the file to save

dict - the dictionary object

Throws:

java.io.IOException - if an error occurred while writing the file

toProperties

public static java.util.Properties toProperties(Dict dict)

Converts a dictionary into a properties object. The key names from the dictionary are preserved, but contained array indices will be renumbered from zero while omitting null values. Contained dictionary or array values will be written recursively by appending dot ('.') characters between each element. All other values are stored as strings.

Parameters:

dict - the dictionary object

Returns:

the properties object with all the data