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Tutorial Addendum On Java - Cilia Groups

 Output: Running AThread 2Ending AThread 2Running AThread 3Running BThread 5Ending BThread 5Running BThread 6Ending BThread 6Running BThread 7Ending BThread 7Running BThread 8Ending BThread 8ThreadGroup name = system Has ancestor cilia accumulation = false # of alive accoutrement = 9 Cilia name = Advertence Handler Cilia name = Finalizer Cilia name = Arresting Dispatcher Cilia name = CompileThread0 # of alive sub cilia groups = 2 ThreadGroup name = main Has ancestor cilia accumulation = true # of alive accoutrement = 5 Cilia name = main Cilia name = AThread 3 # of alive sub cilia groups = 1 ThreadGroup name = Accumulation X Has ancestor cilia accumulation = true # of alive accoutrement = 1 # of alive sub cilia groups = 0java.lang.ThreadGroup Thread Thread Thread Thread java.lang.ThreadGroup Thread Thread Thread Thread java.lang.ThreadGroup ThreadNote that:As expected, new cilia groups were added to the "main" cilia accumulation by default.As expected, new accoutrement are were added to ... Read More by user

Tutorial Addendum On Java - Cilia Groups

 Output: ThreadGroup name = system Has ancestor cilia accumulation = false # of alive accoutrement = 6 Cilia name = Advertence Handler Cilia name = Finalizer Cilia name = Arresting Dispatcher Cilia name = CompileThread0 # of alive sub cilia groups = 1 ThreadGroup name = main Has ancestor cilia accumulation = true # of alive accoutrement = 2 Cilia name = main # of alive sub cilia groups = 0java.lang.ThreadGroup Thread Thread Thread Thread java.lang.ThreadGroup Thread ThreadNote that:There are 4 Cilia altar in the "system" cilia group. I accept no abstraction what they are for. The "main" cilia accumulation contains 2 Cilia objects. But the enumerate() methodcopies alone one cilia item - the "main" thread. However the list() adjustment is accurately advertisement 2 Cilia objects, called "main" and "Thread-0". What is the purpose of "Thread-0" thread? How to get a advertence of this thread?Grouping ThreadsThe next program shows how to add added accoutrement and cilia groups to the ThreadGr... Read More by user

Tutorial Addendum On Java - Cilia Groups

 ThreadGroup ClassThreadGroup: A chic represents a accumulating of Cilia altar and ThreadGroup objects. Features of ThreadGroup class:All altar of ThreadGroup chic are organized as a timberline structure. Each ThreadGroup item haveto accept a ancestor ThreadGroup item in the tree, except the basis object.The basis item of the ThreadGroup timberline is provided and managed bythe Java Basic Apparatus (JVM). Key methods: getParent(): Allotment the ancestor ThreadGroup object. activeCount(): Allotment the amount of alive Cilia altar in this ThreadGroup item and its sub-tree. activeGroupCount(): Allotment the amount of alive ThreadGroup altar in this ThreadGroup item and its sub-tree. enumerate(Thread[] l): Copies alive Cilia altar in this ThreadGroup item and its sub-tree. enumerate(ThreadGroup[] l): Copies alive ThreadGroup altar in this ThreadGroup item and its sub-tree. interrupt(): Calls Thread.interrupt() adjustment on all Cilia altar in this ThreadGroup item and its sub-tree. The Thre... Read More by user

Tutorial Addendum On Java - Accoutrement

 /** * TimerThread.java * Absorb (c) 2002 by Dr. Yang */import java.util.*;import java.text.*;class TimerThread extends Cilia { clandestine changeless final int NORMAL_CLOCK = 1; clandestine changeless final int COUNT_DOWN = 2; clandestine changeless final int STOP_WATCH = 3; clandestine int type; // blazon of clock clandestine int c_millisecond, c_second, c_minute, c_hour; clandestine changeless int remaining_minutes = 5; clandestine changeless int clock_interval = 100; // in milliseconds < 1000 accessible changeless abandoned main(String[] a) { System.out.println("Normal alarm Stop watch Count-down"); TimerThread normal_clock = new TimerThread(NORMAL_CLOCK); TimerThread count_down = new TimerThread(COUNT_DOWN); TimerThread stop_watch = new TimerThread(STOP_WATCH); stop_watch.setDaemon(true); normal_clock.start(); count_down.start(); stop_watch.start(); while (count_down.isAlive()) { System.out.print(normal_clock.getClock()+" "+ stop_watch.getClock()+" "+ count_down.getClock()+" ");... Read More by user

Tutorial Addendum On Java - Accoutrement

 Output of 5 threads: Thread: 0 1 2 3 4 Year: 0 0 0 0 0 Year: 2039 2040 2043 2042 2044 Year: 2067 2040 2048 2042 2044 Year: 2124 2142 2048 2159 2044 Year: 2318 2180 2230 2300 2044 Year: 2353 2325 2230 2300 2335 Year: 2520 2526 2230 2529 2335 Year: 2644 2741 2641 2723 2335 Year: 2758 2792 2641 2723 2776 Year: 3128 3124 2952 3096 3139 Year: 3181 3216 2952 3252 3213 Year: 3689 3667 3559 3605 3657 Year: 3992 3999 3999 3999 3999 Year: 3999 3999 3999 3999 3999Time = 6369Year, ThreadsOutput of 10 thread: Thread: 0 1 2 3 4 5 6 7 8 9 Year: 2936 2948 3237 3242 3208 2954 3182 3232 3169 2963 Year: 2936 3303 3237 3242 3208 3272 3182 3232 3169 2963 Year: 3495 3498 3237 3480 3974 3890 3996 3999 3999 2963 Year: 3999 3999 3999 3999 3999 3999 3999 3999 3999 3999Time = 3925Year, ThreadsOutput of 10 cilia - addition run: Thread: 0 1 2 3 4 5 6 7 8 9 Year: 2222 2239 2174 2275 2245 2142 2213 0 0 2248 Year: 2531 2283 2501 2510 2245 2142 2213 2460 2521 2470 Year: 2531 2283 2583 2624 2547 2142 2213 2460 2556 261... Read More by user

Tutorial Addendum On Java - Accoutrement

 The afterward program shows that how assorted accoutrement can plan calm to account how some weekdays in anniversary year for 2000 years starting from year 2000. In this program, an array, y_days, is declared as static,so it can be aggregate by all the accoutrement to abundance the affected result, the amount of weekdays of a specific year. /** * WeekDayCounter.java * Absorb (c) 2002 by Dr. Yang */import java.util.*;class WeekDayCounter extends Cilia { clandestine changeless final int t_maxi = 5; // best amount of threads clandestine changeless int t_last = -1; // basis of the endure thread clandestine int t_indx; // basis of this thread clandestine changeless int t_year = new int; clandestine changeless boolean t_done = new boolean; clandestine changeless final int y_maxi = 2000; // best amount of years clandestine changeless final int s_year = 2000; // starting year clandestine changeless int y_days = new int; // weekdays clandestine changeless int y_logs = new int; // tracking the t... Read More by user
Tags: years, program, system, starting, beginning, final, value, calculation, public, result, print

Tutorial Addendum On Java - Accoutrement

 Output Priority: (min, norm, max) = (1, 5, 10)Threads: 0 1 2 3 4 Time Steps: 1527 2229 161931 31864 29386 17416 Steps: 3193 3881 175188 44342 41757 20301 Steps: 6499 5536 204244 74234 71608 27221 Steps: 8164 10495 244791 114110 112329 36475 Steps: 11491 10495 257239 142209 139702 43025 Steps: 13157 13805 285516 154633 152887 45909 Steps: 14820 15458 297916 167948 165368 48793 Steps: 16484 18763 327732 197825 195242 59009 Steps: 19817 22073 369925 239372 236753 65448 Steps: 23150 23729 403986 273273 271592 73410 Steps: 26482 27018 416407 286531 284058 76295 Steps: 28127 27018 429632 298998 296468 79299 Steps: 29794 31993 473677 343808 341381 89575 Steps: 33118 33662 486954 371226 368753 95944 Steps: 34780 35317 514379 397811 395301 102193 Steps: 38109 38639 541010 410201 408616 104958 Steps: 39770 40305 553411 423504 421101 111027 Steps: 41433 43640 595710 465923 463501 117757 Steps: 44763 45310 609007 478306 493386 124557 Steps: 48096 46980 638029 508055 519042 130686 Steps: 49759 5031... Read More by user

Tutorial Addendum On Java - Accoutrement

 Output: Hello world! - From the capital program.Hello world! - From a thread.Note that:The program behaves the aforementioned way as the antecedent program: HelloThread.The Cilia item t is created with the appropriate Cilia constructor, which takes a Runnable item as input. If you alpha a Cilia item createdin this way, the run() adjustment of the Runnable item will be accomplished as a new thread.Since our chic is not extending the Cilia chic any more, we charge to call the sleep() absolutely by prefixing the chic name: Thread.May be you are apprehensive why we charge the additional adjustment of creating a new thread, which seems to be beneath beeline advanced than the first method? The acknowledgment is thatJava classes can not be continued from two altered abject classes. So if you arein a bearings area you wish to make a new chic by extending an absolute class to accede some nice appearance of that class, and you aswell wish to makethe new chic executable as a thread, you accept to... Read More by user
Tags: program, programs, times, system, application, class, final, start, method, prime, public, second, turns, object, print

Tutorial Addendum On Java - Synchronization

 Output: No synchronization:Account, ATM 0, ATM 1, ATM 2, ATM 3, ATM 4, Transaction Sum, Balance0, 506.81, 227.06, 286.89, -885.14, 330.11, 465.73, 1051.871, 63.98, 27.74, 413.05, 276.93, -86.81, 694.89, 529.102, -303.05, -283.53, 385.71, 126.36, 136.16, 61.65, 188.653, -62.36, 491.84, 172.51, -548.71, 63.59, 116.87, 182.854, 553.12, 22.86, 1027.99, 52.98, -202.90, 1454.05, 1297.925, 276.85, 33.59, -371.78, -36.76, 363.60, 265.50, 343.826, 313.82, 300.44, 64.48, -321.91, 651.41, 1008.24, 1532.097, -516.72, -22.58, -139.76, -7.58, 352.92, -333.72, 264.268, 19.66, -506.82, 469.41, 437.11, -106.23, 313.13, 243.399, 225.69, -64.89, -301.68, -128.40, 103.83, -165.45, 173.74# of Transactions, 444, 443, 443, 444, 443Synchronized method:Account, ATM 0, ATM 1, ATM 2, ATM 3, ATM 4, Transaction Sum, Balance0, 109.68, 206.15, 482.22, 297.49, -59.65, 1035.89, 1035.891, -123.26, -229.60, 369.57, 187.18, -198.98, 4.91, 4.912, 326.85, 247.02, -124.56, 68.14, 437.90, 955.35, 955.353, -83.52, 154.05, 104... Read More by user

Tutorial Addendum On Java - Synchronization

 clandestine changeless abandoned printResult() { System.out.print("Account"); for (int i=0; i<t_maxi; i++) System.out.print(", ATM "+i); System.out.print(", Transaction Sum, Balance"); for (int j=0; j<a_maxi; j++) { System.out.print(" "+j); continued sum = 0; for (int i=0; i<t_maxi; i++) { sum += t_list.getBalance(j); System.out.print(", "+getCurrency(t_list.getBalance(j))); } System.out.print(", "+getCurrency(sum)+ ", "+getCurrency(balance)); } System.out.print(" # of Transactions"); for (int i=0; i<t_maxi; i++) System.out.print(", "+t_list.transactionCount()); System.out.print(" "); } clandestine changeless Cord getCurrency(long d) { continued i = d/100; continued f = Math.abs(d)%100; Cord fs = String.valueOf(f); if (f<10) fs = "0"+fs; acknowledgment String.valueOf(i)+"."+fs; } accessible changeless continued getStep() { acknowledgment t_step; } accessible changeless int accountCount() { acknowledgment a_maxi; } accessible changeless Accidental getRandom() { acknowledg... Read More by user
Tags: account, transaction, balance, system, class, process, sleep, catch, notes, public, string, false, print

Tutorial Addendum On Java - Synchronization

 Synchronization Sample ProgramNow, let s address a Java program to see how the synchronization techniquecan break the coffer problem. Two classes are advised to simulate a banksystem: BankingThread class: Acting as an ATM machine, demography drop or abjure transaction requests from customers, and allurement the BankingMain chic to perform the transactions.BankingMain class: Acting as the ascendancy center, managing instances of the BankingThread class, and assuming affairs advancing from anniversary BankingThreadinstance.BankingThread class: /** * BankingThread.java * Absorb (c) 2002 by Dr. Yang */import java.util.*;public chic BankingThread extends Cilia { clandestine long t_balance; // acount balance clandestine continued t_count; // amount of affairs done so far accessible BankingThread(ThreadGroup g, Cord n) { super(g,n); t_count = 0; int m = BankingMain.accountCount(); t_balance = new long; for (int i=0; i<m; i++) t_balance = 0; } accessible continued transactionCount() { ackno... Read More by user

Tutorial Addendum On Java - Synchronization

 Synchronization Abutment in JavaInstead of let the programmers to architecture their own locks, administer the synchronization blocks, and administer the synchronization rules, Java offers a synchronization adviser on anniversary instance of the Item class, so it can be acclimated as a synchronization lock. Since all classes are sub classes of Object, all altar in Java can be acclimated as synchronization locks. Java aswell offers three means to ascertain synchronized blocks.Synchronized Chic Method: class class_name { changeless synchronized blazon method_name() { account block }}All the statements in the adjustment become the synchronized block, and the chic item is the lock.Synchronized Instance Method: class class_name { synchronized blazon method_name() { account block }}All the statements in the adjustment become the synchronized block, and the instance item is the lock.Synchronized Statement: class class_name { blazon method_name() { synchronized (object) { account block } }}All... Read More by user

Tutorial Addendum On Java - Synchronization

 Why SynchronizationThe better problem of acceptance assorted accoutrement administration the aforementioned data setis that one operation in one cilia could bang with addition operationin addition accoutrement on the aforementioned data. If this happens, the aftereffect is un-desirable.Let s use a coffer appliance program as an example. Bold that the programhas assorted accoutrement running, with anniversary cilia abutting an ATM system, and you accept a extenuative annual in the coffer with $100.00, now you and your acquaintance are traveling to two altered ATMs at about the aforementioned time, and aggravating to abjure $50.00 from your account, what do you anticipate it will happen? If the accoutrement are active independently, the afterward could happen: Time 01:01 02:01 03:01 04:01 +----------+---------+---------+-------Thread 1 Get SetAction You Annual Annual You Abjure Antithesis Antithesis Receive $50.00 $100.00 $50.00 $50.00 Time 01:02 02:02 03:02 04:02 -+----------+---------+... Read More by user

Tutorial Addendum On Java - Beheading Of Java Programs

 Execution ConsoleWhen the JVM is active a Java appliance program, it needs a animate windowto provides 3 predefined ascribe and achievement streams to the Java program: to:System.in: Accepted ascribe beck affiliated to the animate window.System.out: Accepted achievement beck affiliated to the animate window. System.err: Accepted absurdity beck affiliated to the animate window. When you use J2SDK amalgamation to assassinate a Java program, the animate window is thesame window area you entered the "java" command. Note that all 3 accepted streams are authentic as a accessible changeless capricious of the "System"class. We accept acclimated the "System.out" in our first Java program, Hello.java, to book the accost bulletin on the animate window. Actuality is addition program that uses all 3 accepted streams: /** * Reverser.java * Absorb (c) 2002 by Dr. Yang */import java.io.*;public chic Reverser { accessible changeless abandoned main(String[] arg) { InputStream in1 = System.in; InputStrea... Read More by user
Tags: program, system, character, window, positions, connected, console, streams, command, lines, public, string

Tutorial Addendum On Java - Beheading Of Java Programs

 Execution Access PointAs mentioned in the antecedent section, a Java appliance program haveto accept a starting chic with a appropriate adjustment alarm main() as the beheading access point. The main() adjustment haveto be authentic as follows: accessible changeless abandoned main(String a) { // account block }Note that the main() adjustment is a chic method, authentic as "static". So if itis alleged by the JVM, no instance of the starting chic will be created.The constant of the main() adjustment is an arrangement of "String", which contains the additional arguments afterwards the chic name altercation in the "java" command line.Let s use the afterward Java program to allegorize how those arguments are passed into the main() method: /** * CommandLine.java * Absorb (c) 2002 by Dr. Yang */class CommandLine { accessible changeless abandoned main(String a) { System.out.println("Number of arguments = "+a.length); for (int i=0; i<a.length; i++) { System.out.println(" a = "+a); } }}After ... Read More by user

Tutorial Addendum On Java - Beheading Of Java Programs

 Execution ProcessA Java appliance program is create of one or added classes and aught or added interfaces. One of the chic musthave the main() adjustment as the beheading starting point of the program.There are 3 accomplish complex in creating the classes and interfaces of a Java program, and active the program: Creating Classes and Interfaces: Creating a argument book for anniversary chic orinterface that contains the analogue of the chic or interface accounting in Javalanguage statements.Such a book is alleged antecedent cipher file, which haveto accept a book name identical to thename of the chic or interface authentic in the file, and an addendum of ".java".Compiling Classes and Interfaces: Converting a antecedent cipher book into a bytecodefile that contains the aforementioned analogue of the chic or interface accounting Java Basic Machine (JVM) instructions. A bytecode book haveto accept a book name identical to thename of the chic or interface authentic in the file, and an adden... Read More by user
Tags: program, files, directories, creating, starting, class, classes, contains, search, directory, format, interface, command, source

Tutorial Addendum On Java - Beheading Ambiance

 Output: D:\write_20021217java_20021217semoryUsageMemory acceptance afore arrangement allocation: Chargeless anamnesis = 1777248 Absolute anamnesis = 2031616 Best anamnesis = 134217728 Anamnesis acclimated = 254368Memory acceptance afterwards arrangement allocation: Chargeless anamnesis = 1897280 Absolute anamnesis = 4132864 Best anamnesis = 134217728 Anamnesis acclimated = 2235584Memory acceptance summary: Allocated to the arrangement = 2097152 Anamnesis acceptance access = 1981216 Aerial of individual arrangement = -115936The achievement was actual surprising. An arrangement for autumn 2097152 bytes (2MB) of data wasallocated. But the anamnesis acceptance was added by alone 1981216 bytes. Somehow the JVMfreed up some anamnesis during the arrangement allocation process. If you attending carefully on the ethics of absolute anamnesis afore and afterwards the arrangement allocation, you can see that the JVMhad requested an added 2MB of anamnesis from the operating arrangement into adjustm... Read More by user

Tutorial Addendum On Java - Beheading Ambiance

 The program seems to be confusing:Why do I charge two altered methods to retrieve the anamnesis information?Why are the methods alleged again 5 times?Why are the press statements for the getMemoryInfo() adjustment not followingthe adjustment alarm statements immediately?Answers to these questions are in the achievement of the program: Print anamnesis advice - move = 0 Chargeless anamnesis = 1777568 Absolute anamnesis = 2031616 Best anamnesis = 134217728 Anamnesis acclimated = 254048Print anamnesis advice - move = 1 Chargeless anamnesis = 1774712 Absolute anamnesis = 2031616 Best anamnesis = 134217728 Anamnesis acclimated = 256904Print anamnesis advice - move = 2 Chargeless anamnesis = 1772496 Absolute anamnesis = 2031616 Best anamnesis = 134217728 Anamnesis acclimated = 259120Print anamnesis advice - move = 3 Chargeless anamnesis = 1770280 Absolute anamnesis = 2031616 Best anamnesis = 134217728 Anamnesis acclimated = 261336Print anamnesis advice - move = 4 Chargeless anamnesis = 176806... Read More by user
Tags: program, array, system, methods, allocation, statements, memory, method, environment, public, printing

Tutorial Addendum On Java - Beheading Ambiance

 Non-system PropertiesThe arrangement backdrop are infact stored in a map structure. It can aswell be acclimated by the Java appliance program to abundance its own properties. For example, the afterward programstores two non-system backdrop at the beginning, and uses them after in the program: /** * PropertyTest.java * Absorb (c) 2002 by Dr. Yang */public chic PropertyTest { accessible changeless abandoned main(String a) { setProgramInfo(); printMessage(); } accessible changeless abandoned setProgramInfo() { // Modifying a arrangement property System.setProperty("java.io.tmpdir","c:\var\tmp"); // Abacus my own properties System.setProperty("program.name","Property Test"); System.setProperty("program.version","3.01"); } accessible changeless abandoned printMessage() { Cord userName = System.getProperty("user.name"); Cord programName = System.getProperty("program.name"); Cord programVersion = System.getProperty("program.version"); Cord ioTempDir = System.getProperty("java.io.tmpdir"); Sys... Read More by user

Tutorial Addendum On Java - Beheading Ambiance

 System PropertiesJava appliance programs are accomplished central a Java Basic Apparatus (JVM), which is in turnexecuted central an Operating Arrangement (OS). From the Java appliance program point of view, the JVM, calm with the OS, represents the computer system. The backdrop ofthe JVM and the OS are all alleged arrangement properties. A Java appliance program can: Use System.getProperty(String propertyName) to get the amount of a specific systemproperty.Use System.getProperties() to the ethics of all accessible arrangement properties.Here is an archetype program that displays the ethics of all accessible arrangement properties: /** * SysProperties.java * Absorb (c) 2002 by Dr. Yang */import java.util.*;public chic SysProperties { accessible changeless abandoned main(String[] a) { Backdrop sysProps = System.getProperties(); sysProps.list(System.out); }}Output: -- advertisement backdrop --java.runtime.name=Java(TM) 2 Runtime Environment, Stand...sun.boot.library.path=C:j2sdk1.4.1_01jr... Read More by user

 

 

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