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Bonus task | Lesson 10 | Level 7

Java Core
Level 7 , Lesson 10
Available

"Hey, soldier!"

"Good day, Captain!"

"I've got awesome news for you. Here are some exercises to reinforce your skills. Do them every day and your skills will grow at an insane speed. They were created especially for IntelliJ IDEA."

"Those previous exercises were for rookies. I've added some more advanced bonus exercises for the old-timers. Just for veterans."

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18
Task
Java Core, level 7, lesson 10
Locked
CRUD
CrUD: Create, Update, Delete. The program runs with one of the following sets of arguments: -c name sex bd -u id name sex bd -d id -i id Argument values: name (String) sex ("m" or "f") bd (birth date in the following format: "04 15 1990") -c (adds a person with the specified arguments to the end of
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18
Task
Java Core, level 7, lesson 10
Locked
CRUD 2
Batch CrUD: multiple Creations, Updates, Deletions. The program runs with one of the following sets of arguments: -c name1 sex1 bd1 name2 sex2 bd2 ... -u id1 name1 sex1 bd1 id2 name2 sex2 bd2 ... -d id1 id2 id3 id4 ... -i id1 id2 id3 id4 ... Argument values: name (String) sex ("m" or "f") bd (birth
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18
Task
Java Core, level 7, lesson 10
Locked
Restaurant
1. Figure out what the program does. For some reason, the waiter isn't bringing the prepared dishes out to the tables :( 2. Fix the bug. Hint: it's one line
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18
Task
Java Core, level 7, lesson 10
Locked
Shared list
1. Change the Solution class so that it becomes a list. (It must implement the java.util.List interface). 2. The Solution list should only work with Longs. 3. Use the original field. 4. The list will be used by threads, so you need to ensure that all the methods are synchronized.
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9
Task
Java Core, level 7, lesson 10
Locked
Comparable
Implement the Comparable interface in the Beach class. Beaches will be used by threads, so you need to ensure that all the methods are synchronized. Implement the compareTo method so that when two beaches are compared the method returns a positive number if the first beach is better or a nega
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18
Task
Java Core, level 7, lesson 10
Locked
Pharmacy
Implement the Runnable interface in the Pharmacy and Person classes. All threads should run until isStopped is true. Here's the logic for the Pharmacy class: drugController should make a random drug purchase (getRandomDrug) in a random amount (getRandomCount) and wait 300 ms. Here's the logic for th
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5
Task
Java Core, level 7, lesson 10
Locked
Synchronized methods
Set the synchronized modifier only on the methods that need it. The Solution object will be used by threads.
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9
Task
Java Core, level 7, lesson 10
Locked
Superfluous synchronization
The synchronized keyword significantly slows a program, so remove unnecessary synchronized statements in methods.
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5
Task
Java Core, level 7, lesson 10
Locked
Ironing
Back to the daily grind... Add one synchronized keyword to make diana and steve take turns ironing, since there's only one iron! Hint: Use class-level locking.
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5
Task
Java Core, level 7, lesson 10
Locked
ApplicationContext
The ApplicationContext class will be accessible by many threads. Be sure that no data is lost: think about which keyword to put and where.
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9
Task
Java Core, level 7, lesson 10
Locked
ATM
Figure out how the program works. During testing, the log was found to contain the following: ..... Deposit 100, account balance 1100 Deposit 100, account balance 1200 Spend 1000, account balance 100 Insufficient money ..... There's a bug: Money is lost when debiting an account. Find and fix the bug.
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18
Task
Java Core, level 7, lesson 10
Locked
Transactionality
Make the joinData method transactional, i.e. if it fails, then the data must not be changed. 1. Read 2 file names from the console. 2. Read from the files line by line. Read from the first file into allLines, from the second file — into linesForRemoval. In the joinData method: 3. If the allLines lis
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9
Task
Java Core, level 7, lesson 10
Locked
Let's count
1. Make it so that the result is calculated for all the array elements, WITHOUT using Thread.sleep in the main(String[] args) method. 2. Correct the synchronized block so that the values array is filled with 1s
Comments (39)
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Chandan Thapa Level  22, Dubai, United Arab Emirates
24 December 2020
the last task was difficult for me even if it was one line of code.. I figured it out what needs to be added but was trying to add it in all the wrong places...
Agent Smith Level  38
1 September 2020
A good article for those, who don't know what a CRUD is - What is CRUD?
Lawson Level  29, Lagos, Nigeria
1 September 2020
Those crud tasks are too crude for me
Manish Sinha Level  26, london, United Kingdom
26 April 2020
@codegym team, thanks for this beautiful tasks.it would be also very useful to provide some source for learning things we have not learnt but been used there or hint that you could learn this before attempting to understand the task like in last task, we have used Qeue and ConcurrentLinkedQueue and so many like serializable in some task , BigDecimal in some task, Bean in some task. I am not sure if it would be helpful for all, but I would really find it useful though. Ball is in your court as you are experts . at last thanks agains I would like to revist these again and again to better understand the concept.
Attila Level  25
15 April 2020
Great Tasks!
Nyerges Ferenc Level  23, Bükkábrány, Hungary
22 March 2020
Byebye 17 - soon I can get stuff for 18+ :-)
MaGaby2280 Level  29, Guatemala City, Guatemala
12 February 2020
1022 dark matters... I have a feeling I will need them so much in a near future ;o)
Oregano Level  24, Warsaw, Poland
12 February 2020
Goodbye threads (for a while).. I'm not gonna miss you :D
Vesa Level  41, Kaliningrad, Russia
26 January 2020
1015. OK, let's go on.
Piotr Wikarski Level  19, Birmingham, United Kingdom
27 October 2019
After fixing the bug in ATM task, the program works the same as before feixing it..