////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2017 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 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.AnnotationUtility;
import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
/**
* <p>
* Checks the number of parameters that a method or constructor has.
* The default allowable number of parameters is 7.
* To change the number of allowable parameters, set property max.
* Allows to ignore number of parameters for methods with
* @{@link Override} annotation.
* </p>
* <p>
* An example of how to configure the check is:
* </p>
* <pre>
* <module name="ParameterNumber"/>
* </pre>
* <p>
* An example of how to configure the check to allow 10 parameters
* and ignoring parameters for methods with @{@link Override}
* annotation is:
* </p>
* <pre>
* <module name="ParameterNumber">
* <property name="max" value="10"/>
* <property name="ignoreOverriddenMethods" value="true"/>
* </module>
* </pre>
* Java code that will be ignored:
* <pre>
* {@code
*
* @Override
* public void needsLotsOfParameters(int a,
* int b, int c, int d, int e, int f, int g, int h) {
* ...
* }
* }
* </pre>
* @author Oliver Burn
*/
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";
/** {@link Override Override} annotation name. */
private static final String OVERRIDE = "Override";
/** Canonical {@link Override Override} annotation name. */
private static final String CANONICAL_OVERRIDE = "java.lang." + OVERRIDE;
/** Default maximum number of allowed parameters. */
private static final int DEFAULT_MAX_PARAMETERS = 7;
/** The maximum number of allowed parameters. */
private int max = DEFAULT_MAX_PARAMETERS;
/** Ignore overridden methods. */
private boolean ignoreOverriddenMethods;
/**
* Sets the maximum number of allowed parameters.
* @param max the max allowed parameters
*/
public void setMax(int max) {
this.max = max;
}
/**
* Ignore number of parameters for methods with
* @{@link Override} annotation.
* @param ignoreOverriddenMethods set ignore overridden methods
*/
public void setIgnoreOverriddenMethods(boolean ignoreOverriddenMethods) {
this.ignoreOverriddenMethods = ignoreOverriddenMethods;
}
@Override
public int[] getDefaultTokens() {
return getAcceptableTokens();
}
@Override
public int[] getAcceptableTokens() {
return new int[] {TokenTypes.METHOD_DEF, TokenTypes.CTOR_DEF};
}
@Override
public int[] getRequiredTokens() {
return CommonUtils.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.getLineNo(), name.getColumnNo(), MSG_KEY, max, count);
}
}
/** Determine whether to ignore number of parameters for the method.
*
* @param ast the token to process
* @return true if this is overridden method and number of parameters should be ignored
* false otherwise
*/
private boolean shouldIgnoreNumberOfParameters(DetailAST ast) {
//if you override a method, you have no power over the number of parameters
return ignoreOverriddenMethods
&& (AnnotationUtility.containsAnnotation(ast, OVERRIDE)
|| AnnotationUtility.containsAnnotation(ast, CANONICAL_OVERRIDE));
}
}