java/java-impl/src/com/intellij/codeInspection/LossyEncodingInspection.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   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
  17 /*
  18  * Created by IntelliJ IDEA.
  19  * User: cdr
  20  * Date: Aug 6, 2007
  21  * Time: 3:09:55 PM
  22  */
  23 package com.intellij.codeInspection;
  24
  25 import com.intellij.codeInsight.daemon.GroupNames;
  26 import com.intellij.lang.properties.charset.Native2AsciiCharset;
  27 import com.intellij.openapi.fileEditor.impl.LoadTextUtil;
  28 import com.intellij.openapi.util.TextRange;
  29 import com.intellij.openapi.vfs.VirtualFile;
  30 import com.intellij.psi.PsiFile;
  31 import com.intellij.util.ArrayUtil;
  32 import com.intellij.util.SmartList;
  33 import org.jetbrains.annotations.Nls;
  34 import org.jetbrains.annotations.NonNls;
  35 import org.jetbrains.annotations.NotNull;
  36 import org.jetbrains.annotations.Nullable;
  37
  38 import java.nio.ByteBuffer;
  39 import java.nio.CharBuffer;
  40 import java.nio.charset.Charset;
  41 import java.util.List;
  42
  43 public class LossyEncodingInspection extends BaseJavaLocalInspectionTool {
  44   @Nls
  45   @NotNull
  46   public String getGroupDisplayName() {
  47     return GroupNames.INTERNATIONALIZATION_GROUP_NAME;
  48   }
  49
  50   @Nls
  51   @NotNull
  52   public String getDisplayName() {
  53     return InspectionsBundle.message("lossy.encoding");
  54   }
  55
  56   @NonNls
  57   @NotNull
  58   public String getShortName() {
  59     return "LossyEncoding";
  60   }
  61
  62   @Nullable
  63   public ProblemDescriptor[] checkFile(@NotNull PsiFile file, @NotNull InspectionManager manager, boolean isOnTheFly) {
  64     if (ArrayUtil.find(file.getPsiRoots(), file) != 0) return null;
  65     VirtualFile virtualFile = file.getVirtualFile();
  66     if (virtualFile == null) return null;
  67     String text = file.getText();
  68     Charset charset = LoadTextUtil.extractCharsetFromFileContent(file.getProject(), virtualFile, text);
  69
  70     // no sense in checking transparently decoded file: all characters there are already safely encoded
  71     if (charset instanceof Native2AsciiCharset) return null;
  72
  73     int errorCount = 0;
  74     int start = -1;
  75     List<ProblemDescriptor> descriptors = new SmartList<ProblemDescriptor>();
  76     for (int i = 0; i <= text.length(); i++) {
  77       char c = i == text.length() ? 0 : text.charAt(i);
  78       if (i == text.length() || isRepresentable(c, charset)) {
  79         if (start != -1) {
  80           ProblemDescriptor descriptor = manager.createProblemDescriptor(file, new TextRange(start, i), InspectionsBundle.message(
  81             "unsupported.character.for.the.charset", charset), ProblemHighlightType.GENERIC_ERROR_OR_WARNING, isOnTheFly);
  82           descriptors.add(descriptor);
  83           start = -1;
  84
  85           //do not report too many errors
  86           if (errorCount++ > 200) break;
  87         }
  88       }
  89       else {
  90         if (start == -1) {
  91           start = i;
  92         }
  93       }
  94     }
  95
  96     return descriptors.toArray(new ProblemDescriptor[descriptors.size()]);
  97   }
  98
  99   private static boolean isRepresentable(final char c, final Charset charset) {
 100     String str = Character.toString(c);
 101     ByteBuffer out = charset.encode(str);
 102     CharBuffer buffer = charset.decode(out);
 103     return str.equals(buffer.toString());
 104   }
 105 }