Chapter 1 - Introduction to Computers, the Internet and Java

ASCII

"American Standard Code for Information Interchange". ___ is the popular subset of Unicode that represents uppercase and lowercase letters in the English alphabet, digits and some common special characters.

Five Phases of Java Development

1. Edit 2. Compile 3. Load 4. Verify 5. Execute

Logical Units/Components of a PC

1. Input 2. Output 3. Memory 4. Arithmetic and Logic 5. CPU 6. Secondary Storage

Two Java Compilation Phases

1. Source code is translated into bytecodes for portability across JVM's on different computer platforms. 2. During execution, the bytecodes are translated into machine language for the actual computer on which the program executes.

Just-in-time Compiler

A ___ - such as Oracle's Java HotSpot Compiler - translates the bytecodes into the underlying computer's machine language.

Database

A ___ is a collection of data that's organized for easy access and manipulation.

File

A ___ is a group of related records. This contains arbitrary data in arbitrary formats. Can also be viewed as a sequence of bytes - any organization of the bytes in a ___, such as organizing the data into records, is a view created by the application programmer.

Implements

A class ___ zero or more interfaces, each of which can have one or more methods, just as a car implements separate interfaces for basic driving functions, controlling the radio, controlling the heating and air conditioning systems, etc. Just as car menufacturers implement capabilities differently, classes may implement an interface's methods differently.

Hardware

A computer consists of various devices referred to as ___.

Object Oriented Programming

A key programming methodology that's enhancing programmer productivity, thereby reducing software development costs.

Inheritance

A new class of objects can be created conveniently by ___. The new class (SUBCLASS) starts with the characteristics of an existing class (SUPERCLASS), possibly customizing them and adding unique characteristics of its own. For example, an object of class "convertable" is an object of the more general class "automobile", but more specifically, the roof can be raised or lowered.

Machine Dependent

A particular machine language can be used on only one type of computer.

Internet

ARPA - the Advanced Research Projects Agency of the Department of Defense - rolled out plans to network the main computer systems of approximately a dozen ARPA-funded universities and research institutions. ARPA impelemented what quickly became known as the ARPAnet, the precursor of today's ___.

Integrated Development Environments

Also known as IDE's, these provide tools that support the software development process, such as editors, debuggers for locating logic errors (errors that cause programs to execute incorrectly) and more.

Instance

An object is referred to as an ___ of its class.

Bandwidth

Another name for "Information-carrying Capacity". The cost of this has plummeted as enormous demand for communications ___ has attracted intense competition. This improvement is fostering the Information Revolution. ___ - the information-carrying capacity of communications lines - on the Internet has increased tremendously, while hardware costs have plummeted.

Machine Language

Any computer can directly understand only its own ___, defined by its hardware design. Generally consists of strings of numbers (ultimately reduced to 1's and 0's) that instruct computers to perform their most elementary operations one at a time.

Translator Programs

Assemblers are known as ___.

Instance Variables

Attributes are specified by the class's ___. For example, an attribute of a Car can be the number of doors, color, gas tank capacity, etc. Keep in mind a car (object) knows its own fuel level but cannot determine the fuel level of another car (object). Same goes for Objects in programming.

Encapsulatae

Classes (and their objects) ___, i.e., enncase their attributes and methods. Objects may communicate with one another, but they're normally not allowed to know how other objects are implemented - implementation details are hidden within the objects themselves. Also known as information hiding.

Computer Programs

Computers process data under the control of sequences of instructions called ___.

Data Hierarchy

Data items processed by computers form a ___ that becomes larger and more complex in structure as we progress from the simplest data items (called "bits") to richer ones, such as characters and fields.

Volatile

Data that is lost when the computer's power is turned off is ___.

Persistent

Data that is preserved when the computer's power is turned off is ___.

Characters

Digits, letters and special symbols are known as ___.

Bytecode Verifier

During Bytecode Verification (Phase 4), as the classes are loaded, the ___ examines their bytecodes to ensure that they're valid and do not violate Java's security restrictions.

Assembly Languages

English-like abbreviations that represent elementary operations formed the basis of ___.

Runtime Errors/Execution-time Errors

Errors such as division by zero occur as a program runs.

Moore's Law

Every year or two, the capacities of computers have approximately doubled inexpensively.

Data Hierarchy

From large to small. Database Tables Records Fields For example, a table of students might include first name, last name, major, year, student ID number and grade point average fields. The data for each student is a record, and the individual pieces of information in each record are the fields. You can search, sort and otherwise manipulate the data based on its relationship to multiple tables or databases.

HyperText Markup Language (HTML)

In 1989, Tim Berners-Lee of CERN (the European Organization for Nuclear Research) began to develop a technology for sharing information via "hyperlinked" text documents. This is called ___.

World Wide Web Consortium (W3C)

In 1994, Berners-Lee founded the ___, devoted to developing technologies. One of the ___'s goals is to make the web accessible to everyone regardless of disabilities, language or culture.

Class

In Java, we create a program unit called a ___ to house the set of methods that perform the ___'s tasks. A ___ is similar in concept to a car's engineering drawings, which house the design of an accelerator pedal, steering wheel, and so on.

Just-in-time Compilation (JIT)

JVM's typically execute bytecodes using a combination of interpretation and so-called ___.

Phase 4

Java Development Bytecode Verification As the classes are loaded, the bytecode verifier examines their bytecodes. Ensures that they're valid and do not violate Java's security restrictions.

Phase 2

Java Development Compiles a Java Program into BYTECODES. Use the command "javac" (the Java compiler) to compile a program. [javac Welcome.java => Welcome.java] [java Welcome => Welcome.class] If the program compiles, the compiler produces a .class file that contains the compiled version.

Phase 1

Java Development Consists of editing a file with an EDITOR PROGRAM. Linux: vi and emacs Windows: Notepad OSX: TextEdit

Phase 5

Java Development Execution The JVM executes the program's bytecodes. Analyzes the bytecodes are they're interpreted.

Phase 3

Java Development Loading a Program into Memory. The JVM places the program in memory to execute it - this is known as LOADING. Class Loader takes the .class files containing the program's bytecodes and transfers them to primary memory. Also loads any of the .class files provided by Java that your program uses.

Unicode

Java uses ___ characters that are composed of one, two or four bytes (8, 16, or 32 bits). ___ contains characters for many of the world's languages.

Fields

Just as characters are composed of bits, ___ are composed of characters or bytes. A ___ is a group of characters or bytes that conveys meaning. For example, a ___ consisting of uppercase and lowercase letters used to represent someones name. Same goes for their age with ___ of decimal digits.

Reuse

Just as the notion of interchangeable parts was crucial to the Industrial Revolution, reusable classes are crucial to the software revolution that has been spurred by object technology.

Method

Performing a task in a program requires a ___. The ___ houses the program statements that actually perform its tasks. Also hides these statements from its user, just as the accelerator pedal of a car hides from the driver the mechanisms of making the car go faster.

Java Class Libraries

Rich collections of existing classes and methods. Also known as the Java API's (Application Programming Interfaces). Using these instead of writing your own versions (like Dr. Li's painful PFII class). It can improve program performance and shortens program development time.

Record

Several related fields can be used to compose a ___ (implemented as a class in Java). For example, a whole number that represents an ID number, a string of characters represents a name, etc.

TCP/IP

The Internet Protocol (IP) created a true "network of networks", the current architecture of the Internet. The combined set of protocols is now called ___.

High Level Languages

Single statements accomplish substantial tasks. Allow you to write instructions that look almost like everyday English and contain commonly used mathematical notations. For example: grossPay = basePay + overTimePay

Programmers

Software programs guide the computer through ordered actions specified by people called computer ___.

Internet of Things

The Internet is no longer just a network of computers - it's an ___. A thing is any object with an IP address and the ability to send data automatically over a network.

Loading

The JVM places the program in memory to execute it - this is known as ___.

Bytecodes

The Java compiler translates Java source code into ___ that represents the tasks to execute. ___ instructions are platform independent. ___ are portable. The same bytecode instructions can execute on any platform containing a JVM that understands the version of Java in which the bytecode instructions were compiled.

World Wide Web

The ___ is a collection of hardware and software associated with the Internet that allows computer users to locate and view multimedia-based documents on almost any subject.

Class Loader

The ___ takes the .class files containing the program's bytecodes and trasnfers them to primary memory. Also loads any of the .class files provided by Java that your program uses.

Character Set

The computer's ___ is the set of all the characters used to write programs and represent data items on that device.

Relational Database

The most popular database model is the ___ in which data is stored in simple tables.

Transmission Control Protocol (TCP)

The protocol (set of rules) for communicating over the ARPAnet became known as the ___. ___ ensured that messages, consisting of sequentially numbered pieces called packets, were properly routed from sender to receiver, arrived intact and were assembled in the correct order.

Kernel

The software that contains the core components of the operating sysstem is called the ___.

HyperText Transfer Protocol (HTTP)

Tim Berners-Lee wrote communication protocols such as ___ to form the backbone of his new hypertext information system, which he referred to as the World Wide Web.

Assemblers

Translator programs called ___ convert early assembly language programs to machine language.

Method Call

When you drive a car, pressing its gas pedal sends a message to the car to perform a task - that is, to go faster. Similarly, you send messages to an object. Each message is implemented as a ___ that tells a method of the object to perform its task.

Nonfatal Runtime Error

___ allow programs to run to completion, often producing incorrect results.

Big Data

___ applications deal with such massive amounts of data and this field is growing quickly, creating lots of opportunity for software developers.

Interfaces

___ are collections of related methods that typically enable you to tell objects what to do, but not how to do it. From the car analogy, a "basic-driving-capabilities" ___ consisting of a steering wheel, an accelerator pedal and a brake pedal would enable a driver to tell the car what to do. Once you know how to use this ___ for tuning, accelerating and braking, you can drive many types of cars, even though manufacturers may implement these systems differently.

Fatal Runtime Errors

___ cause programs to terminate immediately without having successfully performed their jobs.

Compilers

___ convert high-level language programs into machine language.

Ajax

___ helps Internet-based applications perform like desktop applications.

Refactoing

___ involves reworking programs to make them clearer and easier to maintain while preserving their correctness and functionality. It's widely employed with agile development methodologies. Many IDE's contain built-in ___ tools to do major portions of the reworking automatically.

Java Virutal Machine

___ is a part of the JDK and the foundation of the Java platform. This executes Java bytecodes. This can be represented as "JVM". The ____ is invoked by the JAVA command. For example: [java Welcome]

Windows

___ is a proprietary operating system.

Agile Software Development

___ is a set of methodologies that try to get software implemented faster and using fewer resources.

Virtual Machine

___ is a software application that simulates a computer. It higes the underlying operating system and hardware from the programs that interact with it. If the same VM is implemented on many computer platforms, applications written for that type of VM can be used on all those platforms.

LAMP

___ is an acronym for the open-source technologies that many developers use to build web applications.

Mashup

___ is an applications-development methodology in which you can rapidly develop powerful software applications by combining (often free) complementary web services and other forms of information feeds.

Linux

___ is an open-sourced operating system.

Andriod

___ is the fastest-growing mobile and smartphone operating system. Based on the Linux kernel and uses Java.

Java

___ is used to add dynamic content to web pages that increases the efficiency between web pages and users.

Design Patterns

___ were proven architectures for constructing flexible and maintainable object-oriented software. The field of ___ tries to enumerate those recurring patterns, encouraging software designers to reuse them to develop better-quality software using less time, money and effort.

Unified Modeling Lanauge

___, also known as UML, is the most widely used graphical scheme for modeling object-oriented systems.

Interpreters

___, developed to execute high-level language programs directly, avoid the delay or compilation, although they run slower than compiled programs.