Checkstyle: Usage of ParenPad Check

问题

I am new to Checkstyle though I use it mainly through the Maven Checkstyle plugin.

I have a situation where I think Checkstyle lacks flexibility. It could be me, not being familiar with Checkstyle and its configuration options.

The problem I have is with the ParenPad check with a token type of METHOD_CALL; I believe.

In the majority of the cases I don't allow any spaces after nor before the parenthesis in a method call.

e.g. object.method(arg1);                          Case 1

But when I am using StringBuffer or StringBuilder in building an SQL statement, text for an email or some other long string; I like to provide a LTR feel to the statements used in build up the long string so that it is easier to read.

e.g. buffer.append("String 1 ");                   Case 2
     buffer.append(          variable);
     buffer.append(                 " String 2");

The style that I am trying to get is to allow none, one or many spaces after the left parenthesis of a mehod call but no spaces before the right parenthesis of the method call.

It seems that I cannot configure Checkstyle to allow this. I can get it to accept Case 1 and reject Case 2 or visa-versa but to get it to accept both I need to disable the ParenPad test all together which I find too drastic. I want both cases to be accepted and enforced using the checkstyle rules.

Please advise how I might accomplish this using Checkstyle. What configuration do I need? Are there 'tricks' in using Checkstyle to accomplish this? Are there Checkstyle extension to do what I need? Or do I need to write a custom check?

Seeking any help or advice.

Thanks in advance

回答1:

I have found a work around that I am using now but would like the situation to be improved. I have modified the Checkstyle rule for ParenPad to be as follows:

    <module name="ParenPad">
      <property name="option" value="nospace"/>
      <property name="tokens" value="CTOR_CALL,LPAREN,RPAREN,SUPER_CTOR_CALL"/>
    </module>

Basically it does no rule check for ParenPad for a Method call. While no spaces are enforced for all other occurrences of parenthesis, it is a free-for-all in regards to parenthesis used for a Method call.

What I need is to enforce no space before the right parenthesis of a Method call but allow none, one or more spaces after a left parenthesis of a Method call.

回答2:

You can use the tokens property to achieve the desired effect. Just leave out the LPAREN token in order to release the restriction from the left parenthesis:

<module name="ParenPad">
  <property name="tokens" value="CTOR_CALL,METHOD_CALL,RPAREN,SUPER_CTOR_CALL"/>
</module>

In Eclipse, this would look like so:

来源：https://stackoverflow.com/questions/14048428/checkstyle-usage-of-parenpad-check

标签

java

checkstyle