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https://issues.apache.org/jira/browse/LANG-1643?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Alexander van de Rovaart updated LANG-1643:
-------------------------------------------
Description:
In the constructor the EqualsBuilder the variabele {{bypassReflectionClasses}}
is initialized with an {{new ArrayList()}} and immidiately after that a vaue is
added. This will result in an ArrayList.grow() because the contructor of
ArrayList will initialize is with a zero length array. See attached screenshots
for a stacktrace from a flight recording.
My suggestion would be to initialize the arraylist with a length of 1 (or the
default of 10 that is used in {{java.util.ArrayList}} when it is initially
grown on the first add.) So the calls to {{ArrayList.grow}} and
{{ArrayList.newCapacity}} and {{Arrays.copyOf}} won't be called when calling
the add function after construction.
So the code sample of the constructor would be:
{code:java}
public EqualsBuilder() {
// set up default classes to bypass reflection for
bypassReflectionClasses = new ArrayList<>(1);
bypassReflectionClasses.add(String.class); //hashCode field being lazy
but not transient
}
{code}
!image-2021-02-04-11-45-47-437.png!
!screenshot-1.png!
was:
In the constructor the EqualsBuilder the variabele {{bypassReflectionClasses}}
is initialized with an {{new ArrayList()}} and immidiately after that a vaue is
added. This will result in an ArrayList.grow() because the contructor of
ArrayList will initialize is with a zero length array. See attached screenshots
for a stacktrace from a flight recording.
My suggestion would be to initialize the arraylist with a length of 1 (or the
default of 10 that is used in {{java.util.ArrayList}} when it is initially
grown on the first add.) So the calls to {{ArrayList.grow}} and
{{ArrayList.newCapacity}} and {{Arrays.copyOf}} become obsolete
So the code sample of the constructor would be:
{code:java}
public EqualsBuilder() {
// set up default classes to bypass reflection for
bypassReflectionClasses = new ArrayList<>(1);
bypassReflectionClasses.add(String.class); //hashCode field being lazy
but not transient
}
{code}
!image-2021-02-04-11-45-47-437.png!
!screenshot-1.png!
> Initialize Arraylist in EqualsBuilder with size 1
> -------------------------------------------------
>
> Key: LANG-1643
> URL: https://issues.apache.org/jira/browse/LANG-1643
> Project: Commons Lang
> Issue Type: Improvement
> Components: lang.builder.*
> Environment: {code}
> :~$ java -version
> openjdk version "11.0.9.1" 2020-11-04
> OpenJDK Runtime Environment (build 11.0.9.1+1-Ubuntu-0ubuntu1.20.04)
> OpenJDK 64-Bit Server VM (build 11.0.9.1+1-Ubuntu-0ubuntu1.20.04, mixed mode,
> sharing)
> :~$ uname -a
> Linux ubuntu 5.8.0-41-generic #46~20.04.1-Ubuntu SMP Mon Jan 18 17:52:23 UTC
> 2021 x86_64 x86_64 x86_64 GNU/Linux
> Apache commons lang3 version 3.11
> {code}
> Reporter: Alexander van de Rovaart
> Priority: Minor
> Labels: EqualsBuilder, improvement
> Attachments: image-2021-02-04-11-45-47-437.png, screenshot-1.png
>
>
> In the constructor the EqualsBuilder the variabele
> {{bypassReflectionClasses}} is initialized with an {{new ArrayList()}} and
> immidiately after that a vaue is added. This will result in an
> ArrayList.grow() because the contructor of ArrayList will initialize is with
> a zero length array. See attached screenshots for a stacktrace from a flight
> recording.
> My suggestion would be to initialize the arraylist with a length of 1 (or the
> default of 10 that is used in {{java.util.ArrayList}} when it is initially
> grown on the first add.) So the calls to {{ArrayList.grow}} and
> {{ArrayList.newCapacity}} and {{Arrays.copyOf}} won't be called when calling
> the add function after construction.
>
> So the code sample of the constructor would be:
> {code:java}
> public EqualsBuilder() {
> // set up default classes to bypass reflection for
> bypassReflectionClasses = new ArrayList<>(1);
> bypassReflectionClasses.add(String.class); //hashCode field being
> lazy but not transient
> }
> {code}
> !image-2021-02-04-11-45-47-437.png!
> !screenshot-1.png!
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