Java Filter Library

This is a Java library to match POJO against LDAP-like or JSON-like filters.

Maven artefact

Release

The latest released version of the JFilter library artefact is available as:

<dependency>
    <groupId>fr.inria.jfilter</groupId>
    <artifactId>jfilter-library</artifactId>
    <version>1.2</version>
</dependency>

Snapshot

The currently developed version of the JFilter library artefact is available as:

<dependency>
    <groupId>fr.inria.jfilter</groupId>
    <artifactId>jfilter-library</artifactId>
    <version>1.3-SNAPSHOT</version>
</dependency>

Maven compilation

JFilter is a Maven managed project. All you have to do is to invoke the install command from the root directory (JFILTER_DIR):

cd $JFILTER_DIR
mvn install

API usage

LDAP filters

Currently, the library supports the following LDAP-like filters:

Operator	Description	Supported types	Filter example
=	equals to	String, Number, Object	(firstname = John)
~	differs from	String, Number, Object	(name ~ Smith)
>	more than	Number	(height > 1.6)
>=	more or equals	Number	(height >= 1.6)
<	less than	Number	(age < 20)
<=	less or equals	Number	(age <= 20)
!	not	Filter	!(age<10)
&	and	Filters	&(name=Doe)(firstname=John)
PIPE	or	Filters	PIPE(age<10)(male=true)
wildcards	matches all	String	&(firstname=J*)(name=Do?)
types	conforms to	Object	(objectClass=Person)

public class Person {
    String firstname = "John", name = "Doe";
	int age = 20;
	boolean male = true;
	double height = 1.8 ;
	Address home = new Address(); 
	
	public static class Address {
	    String street = "Main street", city = "New York";
	    int postcode = 10014;
	}

    public static void main(String[] args) {
        Person x = new Person();
        Collection<Person> col = Collections.singleton(x);

        Filter filter1 = FilterParser.instance.parse("age > 18");
        if (filter1.match(x)) // Checks if x is an adult
            System.out.println(x.firstname+" "+x.name+" is more than 18 years old.");

        Filter filter2 = FilterParser.instance.parse("(home.city=New York)");
        if (filter2.match(x)) // Checks if x matches the LDAP filter
            System.out.println(x.firstname+"'s lives in "+x.home.city);

        Filter filter3 = FilterParser.instance.parse("&(firstname=John)(name=D*)");
        if (filter3.match(x)) // Checks if x matches the LDAP filter
            System.out.println(x.firstname+"'s name starts by \"D\"");
            
        if (filter3.match(col)) // Checks if col matches the LDAP filter
            System.out.println(x.firstname+"'s name starts by \"D\"");

        // Filters the content of a collection to keep adults
        Collection<Person> adults = filter1.filter(col);
    }
}

JSON filters

The library also supports the following JSON-like filters:

Operator	Description	Supported types	Filter example
:	equals to	String, Number, Object	{firstname:John}
,	and	Filters	{name:Doe,firstname:John}
wildcards	matches	String	{firstname:J*,name:Do?}
types	conforms to	Object	{objectClass:Person}

public class Person {
    String firstname = "John", name = "Doe";
	int age = 20;
	boolean male = true;
	double height = 1.8 ;
	Address home = new Address(); 
	
	public static class Address {
	    String street = "Main street", city = "New York";
	    int postcode = 10014;
	}

    public static void main(String[] args) {
        Person x = new Person();
        Collection<Person> col = Collections.singleton(x);

        // Creates a POJO filter from the JSON syntax
        Filter filter1 = FilterParser.instance.parse("{name:Doe}");
            
        if (filter1.match(x)) // Checks if x matches the JSON filter
            System.out.println(x.firstname+"'s name is "+x.name);

        if (filter1.match(col)) // Checks if col matches the JSON filter
            System.out.println(x.firstname+"'s name is "+x.name);
            
        // Filters the content of a collection to keep names starting by D
        Filter filter2 = FilterParser.instance.parse("{name:D*}");            
        Collection<Person> named = filter2.filter(col);
    }
}

Licence

Copyright (C) 2012 University Lille 1, Inria

This library is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published
by the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
License for more details.

You should have received a copy of the GNU Library General Public License
along with this library; if not, write to the Free Software Foundation,
Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.