Why brackets are necessary in catch block in java?

Question

In java if we have to execute only one statement after if or for the brackets are not necessary. We can write:

if(condition)
  executeSingleStatement();

or

for(init;condition;incr)
  executeSingleStatement();

But in the case of catch block why we can not omit the brackets? Why this is not possible?

catch(Exception e)
   e.printStackTrace();

Because in most of the case we I have only one statement in catch block which is either e.printStackTrace() while testing or logging statement.

Answer 1

Find a compiler construction textbook and look-up the dangling-else ambiguity.

Given that in Java, and most other languages with horrible syntax, spacing lies. How do you interpret:

try
try
stuff();
catch (FooException exc)
handle(exc);
catch (BarException exc)
handle(exc);
catch (BazException exc)
handle(exc);

Is it:

try {
    try {
        stuff();
    } catch (FooException exc) {
        handle(exc);
    } catch (BarException exc) {
        handle(exc);
    }
} catch (BazException exc) {
    handle(exc);
}

Or:

try {
    try {
        stuff();
    } catch (FooException exc) {
        handle(exc);
    }
} catch (BarException exc) {
    handle(exc);
} catch (BazException exc) {
    handle(exc);
}

The dangling-else ambiguity is resolved by associating the else with the inner-most if. Do we want to add a more complicated complication to handle this poor style? No.

Edit: There's a comment that the example does not cover catch. It would be a proper weird decision to require braces on try but not catch/finally. But anyway, for completeness, consider the following code.

try {
stuff();
} catch (FooException foo)
try {
handle(foo);
} catch (BarException bar)
handle(bar);
catch (BazException baz)
handle(baz);
finally
release();

Is the catch of BazException and finally associated with the inner or outer try? Again the language design committee could have added a ton of grammar to disambiguate, but again explicit style wins. My job at Sun/Oracle would have been a little easier if the language had been simplified to mandate explicit braces everywhere.