ParameterNumberCheck.java
///////////////////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
// Copyright (C) 2001-2024 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
///////////////////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.sizes;
import java.util.Collections;
import java.util.Set;
import com.puppycrawl.tools.checkstyle.StatelessCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil;
import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
/**
* <p>
* Checks the number of parameters of a method or constructor.
* </p>
* <ul>
* <li>
* Property {@code ignoreAnnotatedBy} - Ignore methods and constructors
* annotated with the specified annotation(s).
* Type is {@code java.lang.String[]}.
* Default value is {@code ""}.
* </li>
* <li>
* Property {@code ignoreOverriddenMethods} - Ignore number of parameters for
* methods with {@code @Override} annotation.
* Type is {@code boolean}.
* Default value is {@code false}.
* </li>
* <li>
* Property {@code max} - Specify the maximum number of parameters allowed.
* Type is {@code int}.
* Default value is {@code 7}.
* </li>
* <li>
* Property {@code tokens} - tokens to check
* Type is {@code java.lang.String[]}.
* Validation type is {@code tokenSet}.
* Default value is:
* <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_DEF">
* METHOD_DEF</a>,
* <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CTOR_DEF">
* CTOR_DEF</a>.
* </li>
* </ul>
* <p>
* Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
* </p>
* <p>
* Violation Message Keys:
* </p>
* <ul>
* <li>
* {@code maxParam}
* </li>
* </ul>
*
* @since 3.0
*/
@StatelessCheck
public class ParameterNumberCheck
extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY = "maxParam";
/** Default maximum number of allowed parameters. */
private static final int DEFAULT_MAX_PARAMETERS = 7;
/** Specify the maximum number of parameters allowed. */
private int max = DEFAULT_MAX_PARAMETERS;
/** Ignore number of parameters for methods with {@code @Override} annotation. */
private boolean ignoreOverriddenMethods;
/**
* Ignore methods and constructors annotated with the specified annotation(s).
*/
private Set<String> ignoreAnnotatedBy = Collections.emptySet();
/**
* Setter to specify the maximum number of parameters allowed.
*
* @param max the max allowed parameters
* @since 3.0
*/
public void setMax(int max) {
this.max = max;
}
/**
* Setter to ignore number of parameters for methods with {@code @Override} annotation.
*
* @param ignoreOverriddenMethods set ignore overridden methods
* @since 6.2
*/
public void setIgnoreOverriddenMethods(boolean ignoreOverriddenMethods) {
this.ignoreOverriddenMethods = ignoreOverriddenMethods;
}
/**
* Setter to ignore methods and constructors annotated with the specified annotation(s).
*
* @param annotationNames specified annotation(s)
* @since 10.15.0
*/
public void setIgnoreAnnotatedBy(String... annotationNames) {
ignoreAnnotatedBy = Set.of(annotationNames);
}
@Override
public int[] getDefaultTokens() {
return getAcceptableTokens();
}
@Override
public int[] getAcceptableTokens() {
return new int[] {TokenTypes.METHOD_DEF, TokenTypes.CTOR_DEF};
}
@Override
public int[] getRequiredTokens() {
return CommonUtil.EMPTY_INT_ARRAY;
}
@Override
public void visitToken(DetailAST ast) {
final DetailAST params = ast.findFirstToken(TokenTypes.PARAMETERS);
final int count = params.getChildCount(TokenTypes.PARAMETER_DEF);
if (count > max && !shouldIgnoreNumberOfParameters(ast)) {
final DetailAST name = ast.findFirstToken(TokenTypes.IDENT);
log(name, MSG_KEY, max, count);
}
}
/**
* Determine whether to ignore number of parameters.
*
* @param ast the token to process
* @return true if number of parameters should be ignored.
*/
private boolean shouldIgnoreNumberOfParameters(DetailAST ast) {
return isIgnoredOverriddenMethod(ast) || isAnnotatedByIgnoredAnnotations(ast);
}
/**
* Checks if method is overridden and should be ignored.
*
* @param ast method definition to check
* @return true if method is overridden and should be ignored.
*/
private boolean isIgnoredOverriddenMethod(DetailAST ast) {
return ignoreOverriddenMethods && AnnotationUtil.hasOverrideAnnotation(ast);
}
/**
* Checks if method or constructor is annotated by ignored annotation(s).
*
* @param ast method or constructor definition to check
* @return true if annotated by ignored annotation(s).
*/
private boolean isAnnotatedByIgnoredAnnotations(DetailAST ast) {
return AnnotationUtil.containsAnnotation(ast, ignoreAnnotatedBy);
}
}