MutableExceptionCheck.java
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com.puppycrawl.tools.checkstyle.checks.design |
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Checkstyle |
View: Reasons, Metrics, Source Code
These are the metrics that contribute to the Enerjy Score for this file, ranked by impact. So the metrics listed at the top influence the score to a greater extent that the metrics listed at the bottom.
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////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2007 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.design;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.checks.AbstractFormatCheck;
import java.util.Stack;
/**
* <p> Ensures that exceptions (defined as any class name conforming
* to some regular expression) are immutable. That is, have only final
* fields.</p>
* <p> Rationale: Exception instances should represent an error
* condition. Having non final fields not only allows the state to be
* modified by accident and therefore mask the original condition but
* also allows developers to accidentally forget to initialise state
* thereby leading to code catching the exception to draw incorrect
* conclusions based on the state.</p>
*
* @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a>
*/
public final class MutableExceptionCheck extends AbstractFormatCheck
{
/** Default value for format property. */
private static final String DEFAULT_FORMAT = "^.*Exception$|^.*Error$";
/** Stack of checking information for classes. */
private final Stack mCheckingStack = new Stack();
/** Should we check current class or not. */
private boolean mChecking;
/** Creates new instance of the check. */
public MutableExceptionCheck()
{
super(DEFAULT_FORMAT);
}
/** {@inheritDoc} */
public int[] getDefaultTokens()
{
return new int[] {TokenTypes.CLASS_DEF, TokenTypes.VARIABLE_DEF};
}
/** {@inheritDoc} */
public int[] getRequiredTokens()
{
return getDefaultTokens();
}
/** {@inheritDoc} */
public void visitToken(DetailAST aAST)
{
switch (aAST.getType()) {
case TokenTypes.CLASS_DEF:
visitClassDef(aAST);
break;
case TokenTypes.VARIABLE_DEF:
visitVariableDef(aAST);
break;
default:
throw new IllegalStateException(aAST.toString());
}
}
/** {@inheritDoc} */
public void leaveToken(DetailAST aAST)
{
switch (aAST.getType()) {
case TokenTypes.CLASS_DEF:
leaveClassDef();
break;
default:
// Do nothing
}
}
/**
* Called when we start processing class definition.
* @param aAST class definition node
*/
private void visitClassDef(DetailAST aAST)
{
mCheckingStack.push(mChecking ? Boolean.TRUE : Boolean.FALSE);
mChecking =
isExceptionClass(aAST.findFirstToken(TokenTypes.IDENT).getText());
}
/** Called when we leave class definition. */
private void leaveClassDef()
{
mChecking = ((Boolean) mCheckingStack.pop()).booleanValue();
}
/**
* Checks variable definition.
* @param aAST variable def node for check.
*/
private void visitVariableDef(DetailAST aAST)
{
if (mChecking && (aAST.getParent().getType() == TokenTypes.OBJBLOCK)) {
final DetailAST modifiersAST =
aAST.findFirstToken(TokenTypes.MODIFIERS);
if (!(modifiersAST.findFirstToken(TokenTypes.FINAL) != null)) {
log(aAST.getLineNo(), aAST.getColumnNo(), "mutable.exception",
aAST.findFirstToken(TokenTypes.IDENT).getText());
}
}
}
/**
* @param aClassName class name to check
* @return true if a given class name confirms specified format
*/
private boolean isExceptionClass(String aClassName)
{
return getRegexp().matcher(aClassName).find();
}
}
The table below shows all metrics for MutableExceptionCheck.java.
| Metric | Value | Description | |
|---|---|---|---|