Stack trace does not print in the correct order with other messages on the console

Question

Why is there a stack trace for the next Java program not showing in the correct order on the console screen? It mixes with other messages on the screen.

Is there any parallelism that causes it?

Java program:

package evm;

public class Client {

    public static void main(String[] args) {
        EVM evm = new EVM();

        try {
            evm.setCandidates(90);   /**An Exception thrown here**/
        } catch (CandidatesOutOfLimitsException e) {
            e.printStackTrace();
            //System.out.print(e.getMessage());
        }

        try {
            evm.voteForCandidate(43);    /**An Exception thrown here**/
        } catch (BallotUnitOffException e1) {
            e1.printStackTrace();
            //System.out.print(e1.getMessage());
        }

        evm.pressBallotButton();

        System.out.println(evm);  //other messages
        evm.switchOn();
        System.out.println(evm);  //other messages

        try {
            evm.voteForCandidate(43);    /**An Exception thrown here**/
        } catch (BallotUnitOffException e) {
            e.printStackTrace();
            //System.out.print(e.getMessage());
        }
    }

}

I commented out the lines that throw an exception.

run 1:

evm.CandidatesOutOfLimitsException: Number of Candidates cannot exceed 64
    at evm.EVM.setCandidates(EVM.java:41)
    at evm.Client.main(Client.java:9)
evm.BallotUnitOffException: Ballot Unit is not On
    at evm.BallotUnit.pressCandidateButton(BallotUnit.java:38)
    at evm.EVM.voteForCandidate(EVM.java:59)
    at evm.Client.main(Client.java:16)
evm.BallotUnitOffException: Ballot Unit is not On
    at evm.BallotUnit.pressCandidateButton(BallotUnit.java:38)
    at evm.EVM.voteForCandidate(EVM.java:59)
    at evm.Client.main(Client.java:28)

Control Unit State: evm.Off@42a57993
On Lamp: evm.Off@15db9742Ballot Unit: Ready Lamp: evm.Off@6d06d69c
Slide Switch:evm.SlideSwitchOne@7852e922
Ballot Unit: Ready Lamp: evm.Off@4e25154f
Slide Switch:evm.SlideSwitchTwo@70dea4e
Ballot Unit: Ready Lamp: evm.Off@5c647e05
Slide Switch:evm.SlideSwitchThree@33909752
Ballot Unit: Ready Lamp: evm.Off@55f96302
Slide Switch:evm.SlideSwitchFour@3d4eac69


Control Unit State: evm.On@28d93b30
On Lamp: evm.On@75b84c92Ballot Unit: Ready Lamp: evm.On@6bc7c054
Slide Switch:evm.SlideSwitchOne@7852e922
Ballot Unit: Ready Lamp: evm.On@232204a1
Slide Switch:evm.SlideSwitchTwo@70dea4e
Ballot Unit: Ready Lamp: evm.On@4aa298b7
Slide Switch:evm.SlideSwitchThree@33909752
Ballot Unit: Ready Lamp: evm.On@7d4991ad
Slide Switch:evm.SlideSwitchFour@3d4eac69

run 2:

evm.CandidatesOutOfLimitsException: Number of Candidates cannot exceed 64
    at evm.EVM.setCandidates(EVM.java:41)
    at evm.Client.main(Client.java:9)
evm.BallotUnitOffException: Ballot Unit is not On
    at evm.BallotUnit.pressCandidateButton(BallotUnit.java:38)
    at evm.EVM.voteForCandidate(EVM.java:59)
    at evm.Client.main(Client.java:16)

Control Unit State: evm.Off@42a57993
On Lamp: evm.Off@15db9742Ballot Unit: Ready Lamp: evm.Off@6d06d69c
Slide Switch:evm.SlideSwitchOne@7852e922
Ballot Unit: Ready Lamp: evm.Off@4e25154f
Slide Switch:evm.SlideSwitchTwo@70dea4e
Ballot Unit: Ready Lamp: evm.Off@5c647e05
Slide Switch:evm.SlideSwitchThree@33909752
Ballot Unit: Ready Lamp: evm.Off@55f96302
Slide Switch:evm.SlideSwitchFour@3d4eac69


Control Unit State: evm.On@28d93b30
On Lamp: evm.On@75b84c92Ballot Unit: Ready Lamp: evm.On@6bc7c054
Slide Switch:evm.SlideSwitchOne@7852e922
Ballot Unit: Ready Lamp: evm.On@232204a1
Slide Switch:evm.SlideSwitchTwo@70dea4e
Ballot Unit: Ready Lamp: evm.On@4aa298b7
Slide Switch:evm.SlideSwitchThree@33909752
Ballot Unit: Ready Lamp: evm.On@7d4991ad
Slide Switch:evm.SlideSwitchFour@3d4eac69

evm.BallotUnitOffException: Ballot Unit is not On
    at evm.BallotUnit.pressCandidateButton(BallotUnit.java:38)
    at evm.EVM.voteForCandidate(EVM.java:59)
    at evm.Client.main(Client.java:28)

Similarly, I get some other patterns every time I run it. Does anyone explain this behavior.

I use

Eclipse Java EE IDE for web developers.

Version: Luna Release (4.4.0)

Build Code: 20140612-0600

We apologize for the lengthy question.

Answer 1

, Eclipse.

System.out System.err - PrintStream , , , , , , , , ( ).

System.err.flush() , System.out.flush() std .