////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2008 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.imports;
import com.google.common.collect.Sets;
import com.puppycrawl.tools.checkstyle.api.Check;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.FullIdent;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.api.Utils;
import java.util.Set;
/**
* <p>
* Checks for unused import statements.
* </p>
* <p>
* An example of how to configure the check is:
* </p>
* <pre>
* <module name="UnusedImports"/>
* </pre>
*
* Compatible with Java 1.5 source.
*
* @author Oliver Burn
* @version 1.1
*/
public class UnusedImportsCheck extends Check
{
/** flag to indicate when time to start collecting references */
private boolean mCollect;
/** set of the imports */
private final Set<FullIdent> mImports = Sets.newHashSet();
/** set of references - possibly to imports or other things */
private final Set<String> mReferenced = Sets.newHashSet();
/** Default constructor. */
public UnusedImportsCheck()
{
}
@Override
public void beginTree(DetailAST aRootAST)
{
mCollect = false;
mImports.clear();
mReferenced.clear();
}
@Override
public void finishTree(DetailAST aRootAST)
{
// loop over all the imports to see if referenced.
for (FullIdent imp : mImports) {
if (!mReferenced.contains(Utils.baseClassname(imp.getText()))) {
log(imp.getLineNo(),
imp.getColumnNo(),
"import.unused", imp.getText());
}
}
}
@Override
public int[] getDefaultTokens()
{
return new int[] {
TokenTypes.PACKAGE_DEF,
TokenTypes.ANNOTATION_DEF,
TokenTypes.CLASS_DEF,
TokenTypes.ENUM_DEF,
TokenTypes.IDENT,
TokenTypes.IMPORT,
TokenTypes.INTERFACE_DEF,
TokenTypes.STATIC_IMPORT,
};
}
@Override
public int[] getRequiredTokens()
{
return getDefaultTokens();
}
@Override
public void visitToken(DetailAST aAST)
{
if (aAST.getType() == TokenTypes.IDENT) {
if (mCollect) {
processIdent(aAST);
}
}
else if (aAST.getType() == TokenTypes.IMPORT) {
processImport(aAST);
}
else if (aAST.getType() == TokenTypes.STATIC_IMPORT) {
processStaticImport(aAST);
}
else if ((aAST.getType() == TokenTypes.CLASS_DEF)
|| (aAST.getType() == TokenTypes.INTERFACE_DEF)
|| (aAST.getType() == TokenTypes.ENUM_DEF)
|| (aAST.getType() == TokenTypes.ANNOTATION_DEF)
|| (aAST.getType() == TokenTypes.PACKAGE_DEF))
{
mCollect = true;
}
}
/**
* Collects references made by IDENT.
* @param aAST the IDENT node to process
*/
private void processIdent(DetailAST aAST)
{
final DetailAST parent = aAST.getParent();
final int parentType = parent.getType();
if (((parentType != TokenTypes.DOT)
&& (parentType != TokenTypes.METHOD_DEF))
|| ((parentType == TokenTypes.DOT)
&& (aAST.getNextSibling() != null)))
{
mReferenced.add(aAST.getText());
}
}
/**
* Collects the details of imports.
* @param aAST node containing the import details
*/
private void processImport(DetailAST aAST)
{
final FullIdent name = FullIdent.createFullIdentBelow(aAST);
if ((name != null) && !name.getText().endsWith(".*")) {
mImports.add(name);
}
}
/**
* Collects the details of static imports.
* @param aAST node containing the static import details
*/
private void processStaticImport(DetailAST aAST)
{
final FullIdent name =
FullIdent.createFullIdent(
(DetailAST) aAST.getFirstChild().getNextSibling());
if ((name != null) && !name.getText().endsWith(".*")) {
mImports.add(name);
}
}
}