Inefficient new Byte, Integer, Character constructor calls in ASM ClassReader [SPR-12365]

[spring-projects-issues]

vincent Kim opened SPR-12365 and commented

There are some inefficient new Byte, Character, Integer constructor in ClassReader class.

->
ex) av.visit(name, new Byte((byte) readInt(items[readUnsignedShort(v)])));

It would be better for performance to use static method, valueOf(),.

Such as Byte.valueOf(), Character.valueOf(), Integer.valueOf().

In valueOf method, cached values will be returned.

For giving better performance, use valueOf static method instead of new Constructor.

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Affects: 4.1.1

Issue Links:

• #16990 String comparison using .equals() in ASM ClassReader

Referenced from: commits b16048b

[spring-projects-issues]

vincent Kim commented

I have submitted pull request
-> #674

[spring-projects-issues]

Juergen Hoeller commented

It's worth noting that this is ASM code, not Spring code. However, since we effectively include our own fork of ASM there, we can apply optimizations.

As for the actual optimization, that's a good catch. However, it seems even more attractive to change that code to autoboxing (i.e. just pass in the primitive values) since the JVM will then internally use valueOf itself.

Juergen

[spring-projects-issues]

vincent Kim commented

ValueOf method is replaced to autoboxing, as Juergen said.

I have submitted pull request
-> #680

Thanks.

[spring-projects-issues]

Juergen Hoeller commented

Thanks for updating the pull request - however, I've already applied a corresponding change to master a few days ago...

Let me know if there is anything else to change still.

Juergen