Concurrent threads adding to ArrayList at same time - what happens?

Posted by Marcus on Stack Overflow See other posts from Stack Overflow or by Marcus
Published on 2010-04-26T18:46:03Z Indexed on 2010/04/26 18:53 UTC
Read the original article Hit count: 349

Filed under:

java

|

arraylist

|

synchronization

|

concurrency

We have multiple threads calling add(obj) on an ArrayList.

My theory is that when add is called concurrently by two threads, that only one of the two objects being added is really added to the ArrayList. Is this plausable?

If so, how do you get around this? Use a synchronized collection like Vector?

© Stack Overflow or respective owner

Related posts about java

Tomcat 6: Access Control Exception?

as seen on Server Fault - Search for 'Server Fault'
I'm trying to setup a tomcat6 server, and I'm trying to match another setup someone else established. However, my deployment (default Ubuntu install) uses a policy.d/ directory structure, and the established server just uses a catalina.policy file. I've tried setting every entry in policy.d to match… >>> More
Problem in creation MDB Queue connection at Jboss StartUp

as seen on Stack Overflow - Search for 'Stack Overflow'
I am not able to create a Queue connection in JBOSS4.2.3GA Version & Java1.5, as I am using MDB as per the below details. I am putting this MDB in a jar file(named utsJar.jar) and copied it in deploy folder of JBOSS, In the test env. this MDB works well but in another env. [ env settings and… >>> More
failing to establish connection between Postgres db and gwt

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am using Postgres and gwt 2.0 for one of my applications. I am facing problem connecting to the database. When I try to connect it gives "ClassNotFoundException". Here is what I get when I try to connect to database: java.lang.ClassNotFoundException: org.postgresql.Driver at java.net… >>> More
failing to establish connection between postgre db and gwt

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, For i am using postgre and gwt 2.0 for one of my applications. I am facing problem connecting to the database. When i try to connect it gives "ClassNotFoundException". Here is what i get when i try to connect to database: java.lang.ClassNotFoundException: org.postgresql.Driver at java.net… >>> More
Migration and deployement problems JBoss 4.2.2.GA to JBoss 6.0.0.M2

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I'm trying to migrate an application running on JBoss 4.2.2.GA to JBoss 6.0.0.M2 I give you some log to explain my problem : boot.log : 2010-03-16 09:59:29,406 ERROR [org.jboss.system.server.profileservice.ProfileServiceBootstrap] (Thread-2) Failed to load profile: Summary of incomplete deployments… >>> More

Related posts about arraylist

Convert Java Arraylist return from Java WebService to C# Arraylist

as seen on Stack Overflow - Search for 'Stack Overflow'
In my C# program, I would like to consume the Java Web Service Method which replies the java.Util.ArrayList. I don't know how to convert the Java ArrayList to C# ArrayList. This is Java Codes @WebMethod @WebResult(name = "GetLastMessages") @SuppressWarnings("unchecked") public ArrayList<Message>… >>> More
Data from 6 ArrayLists into a single JTable - Java Swing

as seen on Stack Overflow - Search for 'Stack Overflow'
I have created a JTable which is populated by various arraylists which get their data from a text list using a "~" to split. The issue I am having is that the table is displaying all data from the list on a single row. For example: Column1 Column2 Column2 Column2 … >>> More
java arraylist : same values to a new arraylist

as seen on Stack Overflow - Search for 'Stack Overflow'
public static void rechnung(List<String> array) { for (int i = 0; i < array.size(); i++) { for (int j = 0; j < array.size(); j++) { if (i != j) { System.out.println(array.get(i) + " gleich " + array… >>> More
JAVA: Sort ArrayList<ArrayList<Integer>> on multiple columns

as seen on Stack Overflow - Search for 'Stack Overflow'
First, I did do my homework searching before posting here. My requirement seems to be slightly different compared to questions posted out there. I have a matrix like ArrayList<ArrayList<Integer>> in the following form | id1 | id2 | score | |-----|-----|-------| | 1 | 3 | 95% | |… >>> More
convert ArrayList.toString() back to ArrayList in one call

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a toString() representation of an ArrayList. Copying the toString() value to clipboard, I want to copy it back into my IDE editor, and create the ArrayList instance in one line. In fact, what I'm really doing is this: my ArrayList.toString() has data I need to setup a unit test. I want… >>> More