////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2005 Oliver Burn
//
// 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.usage;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.Scope;
import com.puppycrawl.tools.checkstyle.api.ScopeUtils;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.checks.usage.transmogrify.Definition;
import com.puppycrawl.tools.checkstyle.checks.usage.transmogrify.Reference;
import com.puppycrawl.tools.checkstyle.checks.usage.transmogrify.SymTabAST;
/**
* <p>Checks that a private field is used in more than one method,
* constructor, or initializer.
* </p>
* <p>
* Rationale: a private field used in only one method, constructor, or
* initializer should be replaced by a local variable.
* </p>
* <p>
* An example of how to configure the check is:
* </p>
* <pre>
* <module name="usage.OneMethodPrivateField"/>
* </pre>
*
* @author Rick Giles
*/
public class OneMethodPrivateFieldCheck
extends AbstractUsageCheck
{
/** @see com.puppycrawl.tools.checkstyle.api.Check */
public int[] getDefaultTokens()
{
return new int[] {
TokenTypes.VARIABLE_DEF,
};
}
/** @see com.puppycrawl.tools.checkstyle.checks.usage.AbstractUsageCheck */
public String getErrorKey()
{
return "one.method.private.field";
}
/** @see com.puppycrawl.tools.checkstyle.checks.usage.AbstractUsageCheck */
public boolean mustCheckReferenceCount(DetailAST aAST)
{
final DetailAST mods = aAST.findFirstToken(TokenTypes.MODIFIERS);
return ((mods != null)
&& (ScopeUtils.getScopeFromMods(mods) == Scope.PRIVATE));
}
/** @see com.puppycrawl.tools.checkstyle.checks.usage.AbstractUsageCheck */
public void applyTo(Set aNodes)
{
// apply the check to each private field
final Set methods = new HashSet();
final Iterator it = aNodes.iterator();
while (it.hasNext()) {
methods.clear();
final DetailAST nameAST = (DetailAST) it.next();
// find methods using the field
final Iterator refIt = getReferences(nameAST);
while (refIt.hasNext()) {
final Reference ref = (Reference) refIt.next();
final SymTabAST refNode = ref.getTreeNode();
final DetailAST refDetail = refNode.getDetailNode();
// don't need to check a self-reference
if (refDetail == nameAST) {
continue;
}
DetailAST parent = refDetail.getParent();
while (parent != null) {
final int type = parent.getType();
if ((type == TokenTypes.METHOD_DEF)
|| (type == TokenTypes.CTOR_DEF)
|| (type == TokenTypes.INSTANCE_INIT)
|| (type == TokenTypes.STATIC_INIT))
{
methods.add(parent);
break;
}
// initializer for inner class?
else if (type == TokenTypes.CLASS_DEF) {
break;
}
parent = parent.getParent();
}
}
if (methods.size() == 1) {
log(
nameAST.getLineNo(),
nameAST.getColumnNo(),
getErrorKey(),
nameAST.getText());
}
}
}
/**
* Returns the references to an AST.
* @param aAST the AST for the references.
* @return an iterator for the references to aAST.
*/
private Iterator getReferences(DetailAST aAST)
{
final SymTabAST ident = getASTManager().get(aAST);
final Definition definition =
(Definition) ident.getDefinition();
if (definition != null) {
return definition.getReferences();
}
final Set dummy = new HashSet();
return dummy.iterator();
}
}