plugins/InspectionGadgets/src/com/siyeh/ig/bugs/IteratorNextDoesNotThrowNoSuchElementExceptionInspection.java

   1 /*
   2  * Copyright 2003-2007 Dave Griffith, Bas Leijdekkers
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package com.siyeh.ig.bugs;
  17
  18 import com.intellij.psi.*;
  19 import com.siyeh.HardcodedMethodConstants;
  20 import com.siyeh.InspectionGadgetsBundle;
  21 import com.siyeh.ig.BaseInspection;
  22 import com.siyeh.ig.BaseInspectionVisitor;
  23 import com.siyeh.ig.psiutils.ExceptionUtils;
  24 import com.siyeh.ig.psiutils.IteratorUtils;
  25 import com.siyeh.ig.psiutils.MethodUtils;
  26 import org.jetbrains.annotations.NotNull;
  27
  28 import java.util.Set;
  29
  30 public class IteratorNextDoesNotThrowNoSuchElementExceptionInspection
  31         extends BaseInspection {
  32
  33     @NotNull
  34     public String getID(){
  35         return "IteratorNextCanNotThrowNoSuchElementException";
  36     }
  37
  38     @NotNull
  39     public String getDisplayName(){
  40         return InspectionGadgetsBundle.message(
  41                 "iterator.next.does.not.throw.nosuchelementexception.display.name");
  42     }
  43
  44     @NotNull
  45     public String buildErrorString(Object... infos){
  46         return InspectionGadgetsBundle.message(
  47                 "iterator.next.does.not.throw.nosuchelementexception.problem.descriptor");
  48     }
  49
  50     public BaseInspectionVisitor buildVisitor(){
  51         return new IteratorNextDoesNotThrowNoSuchElementExceptionVisitor();
  52     }
  53
  54     private static class IteratorNextDoesNotThrowNoSuchElementExceptionVisitor
  55             extends BaseInspectionVisitor{
  56
  57         @Override public void visitMethod(@NotNull PsiMethod method){
  58             // note: no call to super
  59             if (!MethodUtils.methodMatches(method, "java.util.Iterator", null,
  60                     HardcodedMethodConstants.NEXT)) {
  61                 return;
  62             }
  63             final Set<PsiType> exceptions =
  64                     ExceptionUtils.calculateExceptionsThrown(method);
  65             for (final PsiType exception : exceptions) {
  66                 if (exception.equalsToText(
  67                         "java.util.NoSuchElementException")) {
  68                     return;
  69                 }
  70             }
  71             if(IteratorUtils.containsCallToIteratorNext(method, null, false)){
  72                 return;
  73             }
  74             final CalledMethodsVisitor visitor = new CalledMethodsVisitor();
  75             method.accept(visitor);
  76             if (visitor.isNoSuchElementExceptionThrown()) {
  77                 return;
  78             }
  79             registerMethodError(method);
  80         }
  81     }
  82
  83     private static class CalledMethodsVisitor
  84             extends JavaRecursiveElementVisitor {
  85
  86         private boolean noSuchElementExceptionThrown = false;
  87
  88         @Override public void visitMethodCallExpression(
  89                 PsiMethodCallExpression expression) {
  90             if (noSuchElementExceptionThrown) {
  91                 return;
  92             }
  93             super.visitMethodCallExpression(expression);
  94             final PsiReferenceExpression methodExpression =
  95                     expression.getMethodExpression();
  96             final PsiElement method = methodExpression.resolve();
  97             if (method == null) {
  98                 return;
  99             }
 100             final Set<PsiType> exceptions =
 101                     ExceptionUtils.calculateExceptionsThrown(method);
 102             for (final PsiType exception : exceptions) {
 103                 if (exception.equalsToText(
 104                         "java.util.NoSuchElementException")) {
 105                     noSuchElementExceptionThrown = true;
 106                 }
 107             }
 108         }
 109
 110         public boolean isNoSuchElementExceptionThrown() {
 111             return noSuchElementExceptionThrown;
 112         }
 113     }
 114 }