Introduction to Spring LDAP

[blueprats]

I. Introduction
It is not necessary to use or know Spring to use this tutorial. It is not necessary to install an LDAP server, because we will use the server Public www.openldap.com. The source code which are used in this tutorial are at the bottom of the tutorial.

II. Installing an LDAP browser
To view the contents of the LDAP server, we need an LDAP browser. I suggest you use Softer LDAP Browser, you may even you any other browser of your choice.

- Download and install Softer LDAP Browser from their official site and do a full install.
- Use the browser to go to the prerecorded OpenLDAP server (www.openldap.com on port 389)
- Open successively Nodes: OpenLDAP / cn = DirectoryManager = People. Select the node with the uid = Kurt.

Right click in the properties of Kurt, you can see the full address of the Kurt Server:
ldap: / / www.openldap.com:389/uid=kurt, ou = People, dc = OpenLDAP, dc = Org

This address consists of 2 parts:
Part 1: www.openldap.com:389 is the internet address and port of the LDAP server.

Part 2: uid = kurt, ou = People, dc = OpenLDAP, dc = Org is the Distinguish Name of kurt registration. It represents the path in the LDAP tree kurt.

III. Download Spring LDAP
Download Library spring-ldap with dependencies ( a zip file) from the official site. This should be easy.

Unzip this archive.
In the directory dist is spring-ldap.jar which must be placed in the CLASSPATH project. In repertory lib is lang.jar-commons, commons-loggin.jar, springbeans. jar, spring-core.jar. All these libraries must be added to CLASSPATH.

[blueprats]

IV. Creating a connection to the LDAP server.
Spring LDAP uses the concept of ContextSource to define a connection to the LDAP server. Create a factory to retrieve a ContextSource correct. ContextSource being a interface, we use LdapConSrc which is an implementation provided by Spring LDAP.
Here is the code:

Public class LdapContextSourceFactory {
	Public static ContextSource getLdapContextSource() throws Exception {
		ldapconsrc consrc = new ldapconsrc();
consrc.setUrl("ldap: / / www.openldap.com:389");
consrc.setBase("dc = OpenLDAP, dc = org");
consrc.afterPropertiesSet();
		return consrc;
	}
}

V. Creating the Subject Person
Spring LDAP can play recordings of people as Person object. Here is our Person class we will get an instance of Kurt. Uid defines the unique identifier on the LDAP server for Person

Public class Person {
	private String id;
	private String frnm;
	private String lsnm;
	Public String getFirstName() {
		return frnm;
	}	
	Public void setFirstName(String frnm) {
		this. frnm = frnm;
	}
	Public String getLastName() {
		return lsnm;
	}
	Public void setLastName(String lsnm) {
		this. lsnm = lsnm;
	}
	Public String getuid() {
		return id;
	}
	Public void setuid(String id) {
		this. id = id;
	}
}

VI. Recovery of a Person object via a DAO.
It is possible to use the DAO pattern to access the Person objects. Here's how proceed in 4 steps

- 1 Creating a Mapper LDAP to Java
A AttributeMapper can correctly instantiate our Person class. It was he who performs the mapping between the structure and the LDAP Person Object Model Java Person. This map is declared as internal internal CAD, because it should not be used outside in this DAO.

Public class PersonDao {
	private static class prsattmap implements AttributesMapper
	{
		Public Person mapFromAttributes(Attributes at)
				throws javax.naming.NamingException {
			Person p = new Person();
p.setFirstName(at.get("givenName").get().function toString() {
    [native code]
}());
p.setLastName(at.get("sn").get().function toString() {
    [native code]
}());
p.setuid(at.get("uid").get().function toString() {
    [native code]
}());
p.setEmail(at.get("mail").get().function toString() {
    [native code]
}());
			return p;
		}
	}
}

- 2 Use LdapTemplate
The implementation of LDAP queries is done via a LdapTemplate.
Here is the code for it

Public class PersonDao {
	...
	private LdapTemplate ldaptem;
	Public void setLdapTemplate(LdapTemplate ldaptem) {
		this. ldaptem = ldaptem;
	}
	...
}

- 3 Set Distinguish Name
The Distinguish Name is the path to registration of Person on the server. The BuildDn function gives a proper Distinguish Name.
Here is the code for it

Public class PersonDao {
	...
	private Name buildDn(String id) {
		DistinguishedName dis = new DistinguishedName();
dis.add("or", "People");
dis.add("id", Uid);
		return dis;
	}
	...
}

- 4 get the instance of the class Person
Simply use the lookup method of ldapTemplate for instance corresponding to primary key, i.e the id in the case of Subject Person.
Here is the code for it

Public class PersonDao {
	...
	Public Person findByPrimaryKey(String id) {
		Name dis = buildDn(id);
		return (Person) ldapTemplate.lookup(dis new
		prsattmap());
	}
	...
}

[blueprats]

VII. Test for DAO

- Let's create a class executable to test our DAO.

Public class TestLdap {
	/** Retrieve has Kurt Person from LDAP server and display Kurt in
	Standard Out */
	Public static void hand(String [] args) {
	}
}

The executable class takes into account any argument.


- Let's add the main method in the Context Source

// 1 Retrieve has LdapContextSource
ContextSource consrc = null;
try {
	consrc = LdapContextSourceFactory.getLdapContextSource();
} catch (Exception e) {
	System.out.System.out.println("Unable to get has LdapContextSource.");
e.printStackTrace();
}

- It must also obtain a LdapTemplate.

// 2 Instanciate has LdapTemplate
LdapTemplate ldaptem = new LdapTemplate();
ldaptem.setContextSource(ldapContextSource);

- Instantiating a Dao and provide him ldapTemplate.

// 3 instanciate has PersonDao
PersonDao c = new PersonDao();
c.setLdapTemplate(ldapTemplate);

- Recovery of Kurt is just using the DAO.

// 4 retrieve has Person and display it
Person prs = cad.findByPrimaryKey("kurt");
System.out.System.out.println("Uid: " + prs.getuid());
System.out.System.out.println("FirstName: " + prs.getFirstName());
System.out.System.out.println("LastName: " + prs.getLastName());
System.out.System.out.println("Email: " + prs.getEmail() + "\ n");

Execute the program and you will get the desired results.


VIII. Improved CAD
Add a method that allows the DAO to retrieve a list of people from their name. The class LikeFilter can use filters with wildcards searches:
Here is the code for it

Public List getPersonNamesByLastName(String lsnm) {
	AndFilter flt = new AndFilter();
flt.and(new EqualsFilter("objectclass", "person"));
flt.and(new LikeFilter("sn", lsnm));
	return ldapTemplate.search("", Filter.encodes(),
	new PersonAttributMapper());
}

- Complement the main class with an example of using this new feature.

// 5 retrieve has list of person
List lsprs = cad.getPersonNamesByLastName("* e *");
for (Object object: lsprs) {
	System.out.System.out.println("Person: " + object);
}

The execution of the main class returns 2 persons in standard output.


IX. Conclusion
Spring LDAP is a library that allows J2EE simply retrieve records LDAP as java objects and free the developer from the Java knowledge LDAP mechanisms. Spring LDAP can also write to the LDAP server. Hope this tutorial was useful.

[blueprats]

X. Source code used in this tutorial

1- Person.java

Public class Person {
	private String id;
	private String frnm;
	private String lsnm;
	private String em;
	Public String getEmail() {
		return em;
	}
	Public void setEmail(String em) {
		this. em = em;
	}
	Public String getFirstName() {
		return frnm;
	}
	Public void setFirstName(String frnm) {
		this. frnm = frnm;
	}
	Public String getLastName() {
		return lsnm;
	}
	Public void setLastName(String lsnm) {
		this. lsnm = lsnm;
	}
	Public String getuid() {
		return id;
	}
	Public void setuid(String id) {
		this. id = id;
	}
	Public String function toString() {
    [native code]
}(){
		return id+" - "+frnm+" "+lsnm;
	}
}

2- PersonDao.java

Public class PersonDao {
	private LdapTemplate ldaptem;
	private static class prsattmap implements AttributesMapper
	{
		Public Person mapFromAttributes(Attributes attrs)
				throws javax.naming.NamingException {
			Person prs = new Person();
prs.setFirstName(attrs.get("givenName").get().function toString() {
    [native code]
}());
prs.setLastName(attrs.get("sn").get().function toString() {
    [native code]
}());
prs.setuid(attrs.get("id").get().function toString() {
    [native code]
}());
prs.setEmail(attrs.get("mail").get().function toString() {
    [native code]
}());
			return prs;
		}
	}
	Public Person findByPrimaryKey(String id) {
		Name d = buildDn(id);
		return (Person) ldaptem.lookup(d new
		prsattmap());
	}
	private Name buildDn(String id) {
		DistinguishedName d = new DistinguishedName();
d.add("or", "People");
d.add("id", id);
		return d;
	}
	Public void setLdapTemplate(LdapTemplate ldaptem) {
		this. ldaptem = ldaptem;
	}
	Public List getPersonNamesByLastName(String lastName) {
		AndFilter flt = new AndFilter();
flt.and(new EqualsFilter("objectclass", "person"));
flt.and(new LikeFilter("sn", LastName));
		return ldaptem.search("", Filter.encodes(),
		new prsattmap());
	}
}

3- LdapContextSourceFactory.java

Public class LdapContextSourceFactory {
	Public static ContextSource getLdapContextSource() throws Exception {
		LdapContextSource ldapconsrc = new LdapContextSource();
ldapconsrc.setUrl("ldap: / / www.openldap.com:389");
ldapconsrc.setBase("dc = OpenLDAP, dc = org");
ldapconsrc.afterPropertiesSet();
		return ldapconsrc;
	}
}

4- TestLdap.java

Public class TestLdap {
	/** Retrieve has Kurt Person from ldap server and display Kurt in
	Standard Out */
	Public static void hand(String [] args) {
		// 1 Retrieve has LdapContextSource
		ContextSource ldapconsrc = null;
		try {
			ldapconsrc =
			LdapContextSourceFactory.getLdapContextSource();
		} catch (Exception e) {
			System.out.System.out.println("Unable to get has
			LdapContextSource.");
			e.printStackTrace();
		}
		// 2 Instanciate has LdapTemplate
		LdapTemplate ldaptem = new LdapTemplate();
ldaptem.setContextSource(ldapconsrc);
		// 3 instanciate has PersonDao
		PersonDao c = new PersonDao();
c.setLdapTemplate(ldaptem);
		// 4 retrieve has Person and display it
		Person prs = c.findByPrimaryKey("kurt");
System.out.System.out.println("Uid: " + prs.getuid());
System.out.System.out.println("FirstName: " + prs.getFirstName());
System.out.System.out.println("LastName: " + prs.getLastName());
System.out.System.out.println("Email: " + prs.getEmail() + "\ n");
		// 5 retrieve has list of prs
		List lstprs = c.getPersonNamesByLastName("* e *");
		for (Object object: lstprs) {
			System.out.System.out.println("Person: " + object);
		}
	}
}