bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/internal/parsing/utils/LaxUTF8Reader.java

   1 package org.simantics.scl.compiler.internal.parsing.utils;
   2
   3 import java.io.BufferedInputStream;
   4 import java.io.FileInputStream;
   5 import java.io.IOException;
   6 import java.io.InputStreamReader;
   7 import java.nio.charset.Charset;
   8 import java.nio.charset.CharsetDecoder;
   9 import java.nio.charset.CodingErrorAction;
  10
  11 public class LaxUTF8Reader extends InputStreamReader {
  12     private static final Charset UTF8 = Charset.forName("UTF-8");
  13     private static final CharsetDecoder UTF8_DECODER = UTF8.newDecoder();
  14
  15     static {
  16         UTF8_DECODER.onMalformedInput(CodingErrorAction.REPLACE);
  17         UTF8_DECODER.onUnmappableCharacter(CodingErrorAction.REPLACE);
  18         UTF8_DECODER.replaceWith("\ufffd");
  19     }
  20
  21     /**
  22      * Skips possible BOM (ef bb bf) in the beginning of the stream.
  23      */
  24     private static BufferedInputStream skipBOM(BufferedInputStream stream) throws IOException {
  25         stream.mark(4);
  26         if(stream.read() == 0xef)
  27             if(stream.read() == 0xbb)
  28                 if(stream.read() == 0xbf)
  29                     return stream;
  30         stream.reset();
  31         return stream;
  32     }
  33
  34     public LaxUTF8Reader(BufferedInputStream stream) throws IOException {
  35         super(skipBOM(stream), UTF8_DECODER);
  36     }
  37
  38     public LaxUTF8Reader(String fileName) throws IOException {
  39         this(new BufferedInputStream(new FileInputStream(fileName)));
  40     }
  41 }