////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2014 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 java.util.List;
import com.google.common.collect.Lists;
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;
/**
* <p>
* Check that finds import statements that use the * notation.
* </p>
* <p>
* Rationale: Importing all classes from a package or static
* members from a class leads to tight coupling between packages
* or classes and might lead to problems when a new version of a
* library introduces name clashes.
* </p>
* <p>
* An example of how to configure the check is:
* </p>
* <pre>
* <module name="AvoidStarImport">
* <property name="excludes" value="java.io,java.net,java.lang.Math"/>
* <property name="allowClassImports" value="false"/>
* <property name="allowStaticMemberImports" value="false"/>
* </module>
* </pre>
*
* The optional "excludes" property allows for certain packages like
* java.io or java.net to be exempted from the rule. It also is used to
* allow certain classes like java.lang.Math or java.io.File to be
* excluded in order to support static member imports.
*
* The optional "allowClassImports" when set to true, will allow starred
* class imports but will not affect static member imports.
*
* The optional "allowStaticMemberImports" when set to true will allow
* starred static member imports but will not affect class imports.
*
* @author Oliver Burn
* @author <a href="bschneider@vecna.com">Bill Schneider</a>
* @author Travis Schneeberger
* @version 2.0
*/
public class AvoidStarImportCheck
extends Check
{
/** the packages/classes to exempt from this check. */
private final List<String> mExcludes = Lists.newArrayList();
/** whether to allow all class imports */
private boolean mAllowClassImports;
/** whether to allow all static member imports */
private boolean mAllowStaticMemberImports;
@Override
public int[] getDefaultTokens()
{
return new int[] {TokenTypes.IMPORT, TokenTypes.STATIC_IMPORT};
}
/**
* Sets the list of packages or classes to be exempt from the check.
* The excludes can contain a .* or not.
* @param aExcludes a list of package names/fully-qualifies class names
* where star imports are ok
*/
public void setExcludes(String[] aExcludes)
{
mExcludes.clear();
for (final String exclude : aExcludes) {
mExcludes.add(exclude.endsWith(".*") ? exclude : exclude + ".*");
}
}
/**
* Sets whether or not to allow all non-static class imports.
* @param aAllow true to allow false to disallow
*/
public void setAllowClassImports(boolean aAllow)
{
mAllowClassImports = aAllow;
}
/**
* Sets whether or not to allow all static member imports.
* @param aAllow true to allow false to disallow
*/
public void setAllowStaticMemberImports(boolean aAllow)
{
mAllowStaticMemberImports = aAllow;
}
@Override
public void visitToken(final DetailAST aAST)
{
if (!mAllowClassImports && (TokenTypes.IMPORT == aAST.getType())) {
final DetailAST startingDot = aAST.getFirstChild();
logsStarredImportViolation(startingDot);
}
else if (!mAllowStaticMemberImports
&& (TokenTypes.STATIC_IMPORT == aAST.getType()))
{
// must navigate past the static keyword
final DetailAST startingDot = aAST.getFirstChild().getNextSibling();
logsStarredImportViolation(startingDot);
}
}
/**
* Gets the full import identifier. If the import is a starred import and
* it's not excluded then a violation is logged.
* @param aStartingDot the starting dot for the import statement
*/
private void logsStarredImportViolation(DetailAST aStartingDot)
{
final FullIdent name = FullIdent.createFullIdent(aStartingDot);
if (isStaredImport(name) && !mExcludes.contains(name.getText())) {
log(aStartingDot.getLineNo(), "import.avoidStar", name.getText());
}
}
/**
* Checks is an import is a stared import.
* @param aImportIdent the full import identifier
* @return true if a start import false if not
*/
private boolean isStaredImport(FullIdent aImportIdent)
{
return (null != aImportIdent) && aImportIdent.getText().endsWith(".*");
}
}