How replace String catenation to StringBuilder append?

Question

How can recursively replace all catenations in toString method to StringBuilder for Java? Is there such a plugin in eclipse? For example: Replace it:

    return "AccountAddresses ["
            + ", corporateAddresses=" + CommonHelper.isNotNull(corporateAddresses)
            + ", corporateDeliveryMinimum=" + corporateDeliveryMinimum
            + ", depot=" +  CommonHelper.isNotNull(depot)
            + ", depotDeliveryMinimum=" + depotDeliveryMinimum
            + ", preSelectedId=" + preSelectedId
            + ", residentialAddresses=" +  CommonHelper.isNotNull(residentialAddresses)
            + ", residentialDeliveryMinimum=" + residentialDeliveryMinimum
            + "]";

at this:

    return new StringBuilder("AccountAddresses [")
            .append(", corporateAddresses=").append(CommonHelper.isNotNull(corporateAddresses))
            .append(", corporateDeliveryMinimum=").append(corporateDeliveryMinimum)
            .append(", depot=").append(CommonHelper.isNotNull(depot))
            .append(", depotDeliveryMinimum=").append(depotDeliveryMinimum)
            .append(", preSelectedId=").append(preSelectedId)
            .append(", residentialAddresses=").append(CommonHelper.isNotNull(residentialAddresses))
            .append(", residentialDeliveryMinimum=").append(residentialDeliveryMinimum)
            .append("]").toString();

What programming language are you working in? Is that C# or Java? You picked so many other tags you forgot to specify a language. — Cody Gray - on strike, Feb 02 '11 at 06:20
@Code Gray - Can you develop C# in Eclipse? Also camel casing is a giveaway... ;-) — Jakub Konecki, Feb 02 '11 at 06:43
Is there a reason you want to do this? I believe your two blocks of code are more or less identical, once the Java compiler is done with it. — Jack Leow, Feb 02 '11 at 07:07

score 14 · Accepted Answer · answered Feb 02 '11 at 13:45

It's a builtin command of Eclipse.

Click on one of the quotation marks (") in your String concatenation.
Bring the Quick Fix menu (Hit Ctrl + 1 on the keyboard).
Select Use 'StringBuilder' for String concatenation.

Magic! Your

    return "foo" + "bar";

changed to

    StringBuilder stringBuilder = new StringBuilder();
    stringBuilder.append("foo");
    stringBuilder.append("bar");
    return stringBuilder.toString();

score 2 · Answer 2 · answered Feb 02 '11 at 07:04

2

I haven't heard of an Eclipse plugin for this - so feel free to ignore this off topic answer - but IntelliJ has an "intention" that will do it for you (at least in 10.0 it does). There is a community edition available if you want to give it a shot.

answered Feb 02 '11 at 07:04

Spyder

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score 1 · Answer 3 · answered Feb 02 '11 at 08:15

1

Do a regex search and replace :

", ([a-zA-z0-9]+)=" \+ CommonHelper\.isNotNull\(([a-zA-z0-9]+)\)  // Find this

append(", $1=").append(CommonHelper.isNotNull($2))    // and replace with this

It is not complete, but you get the idea.

answered Feb 02 '11 at 08:15

fastcodejava

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score 0 · Answer 4 · answered Feb 02 '11 at 07:33

0

Why dont you override the toString method in your class , and implement the stringbuilder append.

answered Feb 02 '11 at 07:33

Dead Programmer

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score 0 · Answer 5 · answered Feb 02 '11 at 09:34

0

I don't think any plugin would do that for you... this would be useless anyways : the Java compiler will do it better than anyone can (and if "StringBuilder" is ever replaced by something better, the Java compiler will be able to use this "something better" if you do not explicitely use a StringBuilder).

answered Feb 02 '11 at 09:34

Kellindil

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By now the compiler replaces every single concatenation with a StringBuilder. This is expensive (from the micro optimization theatre point of view). `a + b + c` becomes `new sb( new sb(a + b) + c )` – DerMike Feb 03 '11 at 09:19
Are you sure about this? If I am not mistaken, this kind of scenario (one StringBuilder per "+") only happens when the compiler cannot do with "appends" (for instance, in a for loop). Something like this : http://stackoverflow.com/questions/1296571/what-happens-when-java-compiler-sees-many-string-concatenations-in-one-line – Kellindil Feb 03 '11 at 15:19

How replace String catenation to StringBuilder append?

5 Answers5