Multiline strings?

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Vadim Tropashko - 08 May 2007 17:40 GMT

Is there a convenient way to have multiline text strings assigned in
java? Something like:

String sqlText = "
select empno, dname, sal from emp, dept
where emp.deptno = dept.deptno
order by sal
";

I came across a project where Stings like this are extracted into a
separate XML file (with all associated XML horrors).

I remember asking this question sometime a decade ago, do things
change:-?

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Steve W. Jackson - 08 May 2007 18:56 GMT

> Is there a convenient way to have multiline text strings assigned in
> java? Something like:
[quoted text clipped - 10 lines]
> I remember asking this question sometime a decade ago, do things
> change:-?

For a literal string as in your example, break it into pieces and use
the "+" operator to concatenate the parts.

It's not a good idea to do this on any large scale in running code (as
in concatenating literals to String variables, for instance) since it
can cause performance and/or memory issues. That's why you have the
StringBuilder and StringBuffer classes. But for compile-time literals,
it shouldn't pose any problems.

= Steve =

Signature

Steve W. Jackson
Montgomery, Alabama

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Vadim Tropashko - 08 May 2007 19:46 GMT

On May 8, 10:56 am, "Steve W. Jackson" <stevewjack...@knology.net>
wrote:

> In article <1178642435.306145.301...@n59g2000hsh.googlegroups.com>,
>
[quoted text clipped - 12 lines]
> > I remember asking this question sometime a decade ago, do things
> > change:-?

> It's not a good idea to do this on any large scale in running code (as
> in concatenating literals to String variables, for instance) since it
> can cause performance and/or memory issues. That's why you have the
> StringBuilder and StringBuffer classes. But for compile-time literals,
> it shouldn't pose any problems.

The

String a += b + c;

part is routinely optimized to StringBuffer. (It is optimization bug
if it is not yet).

OK, on afterthought it seems to be merely a compiler issue. One must
have to redefine string literal in lexer rules.

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Tom Hawtin - 08 May 2007 22:45 GMT

> String a += b + c;

You mean "a += b + c;" or "String a = b + c + d;"?

> part is routinely optimized to StringBuffer. (It is optimization bug
> if it is not yet).

Pessimised, actually. Assuming a, b and c really are String objects,

a = a.concat(b).concat(c);

is likely to be faster (from 1.5 at least).

Tom Hawtin

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Multiline strings?

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