Java Tutorial/J2EE Application/Context

Access a specific object by using the lookup or lookupLink methods

   <source lang="java">

import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.util.Hashtable; import javax.naming.Context; import javax.naming.InitialContext; public class Print {

 public static void main(String[] args) throws Exception {
   Hashtable env = new Hashtable();
   env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.fscontext.RefFSContextFactory");
   env.put(Context.PROVIDER_URL, "file:/tmp/marketing");
   Context initCtx = new InitialContext(env);
   File f = (File) initCtx.lookup("reports/report1.txt");
   if (f != null) {
     BufferedReader br = new BufferedReader(new FileReader(f));
     String l = null;
     while ((l = br.readLine()) != null)
       System.out.println(l);
   }
 }

}</source>

Bind class.

   <source lang="java">

import java.util.Hashtable; import javax.naming.Context; import javax.naming.InitialContext; import javax.naming.NamingException; import javax.naming.Reference; import javax.naming.Referenceable; import javax.naming.StringRefAddr; public class Bind {

 public static void main(String[] args) throws Exception {
   Hashtable env = new Hashtable();
   env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.fscontext.RefFSContextFactory");
   env.put(Context.PROVIDER_URL, "file:/tmp");
   Context initCtx = new InitialContext(env);
   initCtx.rebind("Susan", new Car("Toyota", "Camry"));
   Car c = (Car) initCtx.lookup("Susan");
   System.out.println(c);
 }

} class Car implements Referenceable {

 String make;
 String model;
 public Car(String mk, String md) {
   make = mk;
   model = md;
 }
 public Reference getReference() throws NamingException {
   String cName = Car.class.getName();
   StringRefAddr cRef = new StringRefAddr("Car Description", make + ":" + model);
   String cfName = "asdf";
   Reference ref = new Reference(cName, cRef, cfName, null);
   return ref;
 }
 public String toString() {
   return (make + " " + model);
 }

}</source>

Create Context

   <source lang="java">

import java.util.Hashtable; import javax.naming.Context; import javax.naming.InitialContext; import javax.naming.NamingEnumeration; public class List {

 public static void main(String[] args) throws Exception {
   Hashtable env = new Hashtable();
   env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.fscontext.RefFSContextFactory");
   env.put(Context.PROVIDER_URL, "file:/tmp/marketing");
   Object item = null;
   Context initCtx = new InitialContext(env);
   NamingEnumeration nl = initCtx.list("reports");
   if (nl == null)
     System.out.println("\nNo items in name list");
   else
     while (nl.hasMore()) {
       item = nl.next();
       System.out.println("item"s class is " + item.getClass().getName());
       System.out.println(item);
       System.out.println("");
     }
 }

}</source>

Deleting an Object Binding

   <source lang="java">

import java.util.Hashtable; import javax.naming.Context; import javax.naming.InitialContext; public class Delete {

 public static void main(String[] args) throws Exception {
   String initalContextString = "/tmp/marketing/reports";
   if (args.length < 1) {
     System.out.println("Usage: java Delete filename");
     System.exit(-1);
   }
   System.out.println("This program assumes the context is " + initalContextString);
   Hashtable env = new Hashtable();
   env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.fscontext.RefFSContextFactory");
   env.put(Context.PROVIDER_URL, "file:" + initalContextString);
   Context initCtx = new InitialContext(env);
   System.out.println("Attempting to unbind " + args[0]);
   initCtx.unbind(args[0]);
   System.out.println("Done.");
 }

}</source>

Renaming and Moving an Object

   <source lang="java">

import java.util.Hashtable; import javax.naming.Context; import javax.naming.InitialContext; public class Rename {

 public static void main(String[] args) throws Exception {
   String initialContextString = "/";
   if (args.length < 2) {
     System.out.println("Useage: java Rename filename1 filename2");
     System.exit(-1);
   }
   Hashtable env = new Hashtable();
   env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.fscontext.RefFSContextFactory");
   env.put(Context.PROVIDER_URL, "file:" + initialContextString);
   Context initCtx = new InitialContext(env);
   System.out.println("Renaming " + args[0] + " to " + args[1]);
   initCtx.rename(args[0], args[1]);
 }

}</source>

Replacing and Adding Objects

   <source lang="java">

import java.util.Hashtable; import javax.naming.Context; import javax.naming.InitialContext; import javax.naming.NamingException; public class Changes {

 public static void main(String[] args) throws Exception {
   Hashtable env = new Hashtable();
   env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.fscontext.RefFSContextFactory");
   env.put(Context.PROVIDER_URL, "file:/tmp/marketing");
   Context initCtx = new InitialContext(env);
   initCtx.rename("reports", "oldreports");
   initCtx.createSubcontext("reports");
 }

}</source>

returns a NamingEnumeration of people

   <source lang="java">

import java.util.Hashtable; import javax.naming.Context; import javax.naming.NamingEnumeration; import javax.naming.directory.DirContext; import javax.naming.directory.InitialDirContext; import javax.naming.directory.SearchResult; public class FilterExample {

 public static void main(String[] argc) throws Exception {
   Hashtable env = new Hashtable(11);
   env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
   env.put(Context.PROVIDER_URL, "ldap://MyHost/o=JNDIExample");
   DirContext dctx = new InitialDirContext(env);
   String filter = "(&(cn=E*)(account>1005))";
   NamingEnumeration result = dctx.search("ou=People", filter, null);
   while (result.hasMore()) {
     SearchResult sr = (SearchResult) result.next();
     System.out.println("Result = " + sr.getName());
   }
 }

}</source>

Search Filter Symbols

   <source lang="java">

Symbol Description & Logical and. All items in the list must be true, as in (&(a=1)(b=2) ). | Logical or. One or more of the items must be true, as in (|(a=1)(b=2) ). ! Not. The negated item must be false, as in (!(3=4)) is true. = Checks for equality based on the matching rule of the attribute. ~= Checks for approximate equality based on the matching rule of the attribute. >= Checks that the attribute is greater than the value. <= Checks that the attribute is less than the value. =* Checks for existence of the attribute.

• In an equality test; represents a wildcard representing zero or more characters at that position, as in (name=Alb*).

\ Used for escaping *, (, and ) inside an attribute value.</source>

Using a search result, you could you could use the following program to print the results:

   <source lang="java">

import java.util.Hashtable; import javax.naming.Context; import javax.naming.NamingEnumeration; import javax.naming.directory.Attribute; import javax.naming.directory.Attributes; import javax.naming.directory.BasicAttribute; import javax.naming.directory.BasicAttributes; import javax.naming.directory.DirContext; import javax.naming.directory.InitialDirContext; import javax.naming.directory.SearchResult; public class AttributeExample {

 public static void main(String[] argc) throws Exception {
   Hashtable env = new Hashtable(11);
   env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
   env.put(Context.PROVIDER_URL, "ldap://MyHost/o=JNDIExample");
   DirContext dctx = new InitialDirContext(env);
   Attributes attrs = new BasicAttributes(true);
   attrs.put(new BasicAttribute("email"));
   attrs.put(new BasicAttribute("website", "www.pri.ru"));
   NamingEnumeration result = dctx.search("ou=People", attrs);
   while (result.hasMore()) {
     SearchResult sr = (SearchResult) result.next();
     System.out.println("Result = " + sr.getName());
     Attributes srchAttrs = sr.getAttributes();
     NamingEnumeration attributes = srchAttrs.getAll();
     while (attributes.hasMore()) {
       Attribute attr = (Attribute) attributes.next();
       System.out.println("Attribute: " + attr.getID());
       NamingEnumeration values = attr.getAll();
       while (values.hasMore()) {
         Object value = values.next();
         System.out.println("Value = " + value);
       }
     }
   }
 }

}</source>