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     charset = Native2AsciiCharset.nativeToBaseCharset(charset);
  70
  71     int errorCount = 0;
  72     int start = -1;
  73     List<ProblemDescriptor> descriptors = new SmartList<ProblemDescriptor>();
  74     for (int i = 0; i < text.length(); i++) {
  75       char c = text.charAt(i);
  76       if (isRepresentable(c, charset)) {
  77         if (start != -1) {
  78           ProblemDescriptor descriptor = manager.createProblemDescriptor(file, new TextRange(start, i), InspectionsBundle.message(
  79             "unsupported.character.for.the.charset", charset), ProblemHighlightType.GENERIC_ERROR_OR_WARNING);
  80           descriptors.add(descriptor);
  81           start = -1;
  82
  83           //do not report too many errors
  84           if (errorCount++ > 200) break;
  85         }
  86       }
  87       else {
  88         if (start == -1) {
  89           start = i;
  90         }
  91       }
  92     }
  93     if (start != -1) {
  94       ProblemDescriptor descriptor = manager.createProblemDescriptor(file, new TextRange(start, text.length()), InspectionsBundle.message(
  95         "unsupported.character.for.the.charset", charset), ProblemHighlightType.GENERIC_ERROR_OR_WARNING);
  96       descriptors.add(descriptor);
  97     }
  98
  99     return descriptors.toArray(new ProblemDescriptor[descriptors.size()]);
 100   }
 101
 102   private static boolean isRepresentable(final char c, final Charset charset) {
 103     String str = Character.toString(c);
 104     ByteBuffer out = charset.encode(str);
 105     CharBuffer buffer = charset.decode(out);
 106     return str.equals(buffer.toString());
 107   }
 108 }