Java Glossary

Last updated 1998 June 16 by Roedy Green ©1996-1998 Canadian Mind Products.

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T

T1
an expensive dedicated phone line that can transmit 4,000,000 bits per second.
T3
an very expensive dedicated phone line that can transmit 45,000,000 bits per second.
tabbed dialog
A dialog with tabs the user to bring up cards to view. The closest the Java AWT has to this function is the CardLayout method.
T-Bone
Allows you to connect JavaBeans across multiple hosts.
TCP/IP
Transmission Control Protocol/Internet Protocol. The protocol that Internet uses to transfer packets. It allows interleaving many streams of information on the same connection. It can also be used as a LAN protocol. Other special-purpose Internet protocols are piggybacked on top of it. TCP/IP in turn is piggybacked on top of UDP which is piggybacked on IP. See UDP, IP.
Tea Set
ISofts commercial set of about 25 JavaBeans including Grid, Tabbed Folder, Graph, multi column list, text edit controls, buttons, Form, ComboBox, and Slider.
TELNET
The Internet protocol to log in to a remote computer indirectly through a chain of telecommunications links. The net effect is as if your computer were a character based terminal directly attached to the remote computer. You often log in with the id of "guest" or "anonymous", which will give you low privilege.
Tempest
a commercial product for handling distributed objects.
template
See genericity
template method
See design patterns.
temporary files
Unlike C, Java does not have methods for generating unique temporary filenames. I have written a getTempFile method. View Source.
Tengah
WebLogic's replacement for RMI. See RMI.
ter
similar to "bis". Means new, improved and revised.
text
the text inside a component, e.g. the label on a button, the text in a textarea or textfield. See also label.
TextArea
multiline display of text on the screen. Sometimes you permit the user to edit it. See also TextField.
TextEdit
A text editor written in Java.
textbox
Textboxes in Javanese are referred to as TextAreas for multiline and TextFields for single line.
TextComponent
generic term for either a TextArea or a TextField.
TextField
single line display of text on the screen. Sometimes you permit the user to edit it. See also TextArea.
this
For any instance method, there is a hidden first parameter, a pointer to the object automatically generated by the Java compiler. You can refer to this parameter by the word "this" inside your class. However, if you mention instance variables without any associated pointer, "this" is automatically assumed. "this" is most useful in little accessor functions where you have a parameter with the same name as an instance variable. this.x refers to the instance variable. Plain x refers to the parameter.
thread
Even trivial Java apps are designed to run on multi-cpu machines with execution streams running in parallel. Each stream is called a thread. To learn how threads can communicate with each other see Gerald Hilderink's paper and manual both in Adobe Acrobat PDF format.
three tier
A true three tier database access means you have application code running in both the client and the server. The client and server application code exchange transactions. The application code running on the server accesses the SQL database. dbAnywhere is a quasi-three tier database access. It runs on a server and allows clients to speak the JDBC dialect of SQL and translates the requests into native SQL dialects and hands them off to the SQL server. There is no application specific code on the server. see dbAnywhere, WebLogic.
tip of the iceberg
A class that depends on (uses) all the other classes. So before this class can be considered up-to-date, all its dependencies must be recompiled too (potentially), causing a cascade of compilation. It is the visible tip of the compilation iceberg.
TLA
Three Letter Acronym.
TLIB
Burton Systems Software's second generation version control system. See PVCS.
Together/J
A tool to design and edit, keeping the source tidy. see beautifier.
token
When you break a string up into "words", each chunk is called a token. In parsing source Java code a token would be a name, keyword or an operator. java.util.StringTokenizer lets you define your own simple rules for what counts as a new token. For more advanced tokenising you need a tool like LEX.
toolkit
Interface to the native mode GUI. Methods for finding out details of the particular machine your program is running on.
transparent
a communications channel that can send any arbitrary message through unmolested. It reserves no characters or bit patterns for its own control uses. The channel may still have control facilities. It would just implement them such that they could never be confused with message traffic. For example control information might only be inserted in a wrapper around each little packet of data transmitted.
transparent backgrounds
Java applets are not capable of making their backgrounds transparent. The closest you can come to this ideal is painting the background the same colour or the same pattern as the browser background. This of course does not arrange for the seams to align.
trellis
When two V.32 bis modems talk to each other at 14,400 BPS they make 128 different possible sounds to each other. The sounds are various combinations of phase shifts, and amplitude (loudness) levels of the basic carrier tone. The modem changes the sound 2400 times a second (hence 2400 baud). You could imagine a diagram of the possible sounds arrayed like a lattice or trellis of intersections of phase and amplitude.
trigger
In the JDK 1.1, a component triggers other objects to react by informing its registered listeners that an event occured. In SQL, you can write procedures that are automatically invoked before or after a given row is updated, inserted or deleted. See fire, event
tuples
a language feature of Sather that Java does not have. Java functions can return only a single value. However, Java methods may return an object that has more than one field.
Tutorials
Here are a set of tutorials you can use to learn Java and the various standard library classes. Make sure you have the essential documentation too.
Two's Complement Arithmetic
Java internally uses (or emulates) two's complement arithmetic. Positive numbers are stored in binary. That means that for example the number 13 would be written 0x0d = 00001101 = 1*8 + 1*4 + 0*2 + 1*1. The high order bit is called the sign bit. For signed quantities such as byte, short int and long, when that high order bit is a 1, we consider the number negative. To represent a negative number we first invert each bit, then add 1. We would write -13 this way: 0x0d -> 00001101 -> 11110010 -> 11110011 -> 0xf3. Whenever you do any operation on a byte, it is first sign extended to an int. So so 13 -> 0x0d -> 00001101 -> 00000000000000000000000000001101 -> 0x0000000d and -13 -> 0xf3 -> 11110010 -> 11111111111111111111111111110010 -> 0xfffffff3. When you do arithmetic the results can be too big to represent. The arithmetic is done modulo 2 to the 32nd power, which is a fancy way of saying the high order bits of the result are discarded. The overflow may turn on the high order bit, making the result look negative.
type
When you declare a variable you specify its type, e.g. int, char, Dog, Dalmatian. This information lets the compiler generate the appropriate specific machine code. E.g. + for strings means concatenation, where it means addition for ints.



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