What Is Main Use Of Synchronization In Java
Feb 19, 2015I have no clear idea about Synchronization..What is main purpose of it and where it is useful in realtime.
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Handling IO Synchronization
Sep 16, 2014I have a class (WriteExcel) which writes to an excel file. For those who don't know, Excel doesn't handle multiple access well (or at all).
I then have another class (WriteManager) which creates a new thread for each write command, and then calls a method from the WriteExcel class.
Other classes in my project calls methods from WriteManager to send their requests. My situation looks like this:
1) Thread 1: Someclass -> WriteManager.write1stPage(write) -> Creates Thread 2 -> WriteExcel.write1stPage(write) -> Start Excel Write
2) Thread 1: Someclass -> WriteManager.write2ndPage(write) -> Creates Thread 3 -> WriteExcel.write2ndPage(write) -> Start Excel Write
3) Thread 1: Someclass -> WriteManager.write3rdPage(write) -> Creates Thread 4 -> WriteExcel.write3rdPage(write) -> Start Excel Write
4) Thread 2: Finished writing and ready to save -> Throws exception due to multiple Excel access
5) Thread 3: Finished writing and ready to save -> Throws exception due to multiple Excel access
6) Thread 4: Finished writing and ready to save -> Throws exception due to multiple Excel access
I need to figure out a way to restrict access to WriteExcel until the writing is finished. So I need something like this:
1) Thread 1: Someclass -> WriteManager.write1stPage(write) -> Creates Thread 2 -> WriteExcel.write1stPage(write) -> Start Excel Write
2) Thread 1: Someclass -> WriteManager.write2ndPage(write) -> Creates Thread 3 -> Waits Until WriteExcel is free
3) Thread 1: Someclass -> WriteManager.write3rdPage(write) -> Creates Thread 4 -> Waits Until WriteExcel is free
4) Thread 2: Finished writing and ready to save -> Saves and frees WriteExcel
5) Thread 3: WriteExcel is free -> WriteExcel.write2ndPage(write) -> Start Excel Write
6) Thread 3: Finished writing and ready to save -> Saves and frees WriteExcel
7) Thread 4: WriteExcel is free -> WriteExcel.write3rdPage(write) -> Start Excel Write
8) Thread 4: Finished writing and ready to save -> Saves and frees WriteExcel
What is currently the best approach in java for handling this sort of situation?
Synchronization Of Code In Multiple Instance Of JVM
May 27, 2014There is method in the class of my application and there are four other class which is running in different machine means different jvm and these classes are accessing the method of my class. then how to protect my method from accessing other class at the same time. I am not able to use synchronized keyword because this works only for single jvm.
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[code]....
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try
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Java Code:
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/*
* A program that plays and scores a round of the game Poker Dice. In this game, five dice are rolled. The player is allowed to select a number of those five dice to re-roll. The dice are re-rolled and then scored as if they were a poker hand. The following hands MUST be scored in this assignment:
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* * Two Pair
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* * Full House
* * Four of a Kind
* * Five of a Kind
* For extra credit, you may also implement:
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*/
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[code]....
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[Code].....