Abstract (java net tutorial)

Java net Provides the classes for implementing networking applications. Using the socket classes, you can communicate with any server on the Internet or implement your own Internet server. A number of classes are provided to make it convenient to use Universal Resource Locators (URLs) to retrieve data on the Internet.

Abstract (Java font)

In Java API,the Font class represents fonts, which are used to render text in a visible way. A font provides the information needed to map sequences of characters to sequences of glyphs and to render sequences of glyphs on Graphics and Component objects.

Overview(Java Naming and Directory Interface (JNDI) tutorial)

Naming and directory services play a vital role in intranets and the Internet by providing network-wide sharing of a variety of information about users, machines, networks, services, and applications.

JNDI is an API specified in Java technology that provides naming and directory functionality to applications written in the Java programming language. It is designed especially for the Java platform using Java's object model. Using JNDI, applications based on Java technology can store and retrieve named Java objects of any type. In addition, JNDI provides methods for performing standard directory operations, such as associating attributes with objects and searching for objects using their attributes.

JNDI is also defined independent of any specific naming or directory service implementation. It enables applications to access different, possibly multiple, naming and directory services using a common API. Different naming and directory service providers can be plugged in seamlessly behind this common API. This enables Java technology-based applications to take advantage of information in a variety of existing naming and directory services, such as LDAP, NDS, DNS, and NIS(YP), as well as enabling the applications to coexist with legacy software and systems.

Using JNDI as a tool, you can build new powerful and portable applications that not only take advantage of Java's object model but are also well-integrated with the environment in which they are deployed.

Java HashMap Overview

A map is a way of storing data that minimizes the need for searching when you want to retrieve an object. Each object is associated with a key that is used to determine where to store the reference to the object, and both the key and the object are stored in the map.  

Hash table based implementation of the Map interface. This implementation provides all of the optional map operations, and permits null values and the null key. (The HashMap class is roughly equivalent to Hashtable, except that it is unsynchronized and permits nulls.) This class makes no guarantees as to the order of the map; in particular, it does not guarantee that the order will remain constant over time.

This implementation provides constant-time performance for the basic operations (get and put), assuming the hash function disperses the elements properly among the buckets. Iteration over collection views requires time proportional to the "capacity" of the HashMap instance (the number of buckets) plus its size (the number of key-value mappings). Thus, it's very important not to set the initial capacity too high (or the load factor too low) if iteration performance is important.

HashMap Supports the storage of any type of object in a hash table, sometimes called a map.

Java StringTokenizer Overview

The string tokenizer class allows an application to break a string into tokens. The tokenization method is much simpler than the one used by the StreamTokenizer class. The StringTokenizer methods do not distinguish among identifiers, numbers, and quoted strings, nor do they recognize and skip comments.