lib/jetty/org/eclipse/jetty/util/ReadLineInputStream.java

   1 //
   2 //  ========================================================================
   3 //  Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
   4 //  ------------------------------------------------------------------------
   5 //  All rights reserved. This program and the accompanying materials
   6 //  are made available under the terms of the Eclipse Public License v1.0
   7 //  and Apache License v2.0 which accompanies this distribution.
   8 //
   9 //      The Eclipse Public License is available at
  10 //      http://www.eclipse.org/legal/epl-v10.html
  11 //
  12 //      The Apache License v2.0 is available at
  13 //      http://www.opensource.org/licenses/apache2.0.php
  14 //
  15 //  You may elect to redistribute this code under either of these licenses.
  16 //  ========================================================================
  17 //
  18
  19 package org.eclipse.jetty.util;
  20
  21 import java.io.BufferedInputStream;
  22 import java.io.IOException;
  23 import java.io.InputStream;
  24 import java.nio.charset.StandardCharsets;
  25
  26 /**
  27  * ReadLineInputStream
  28  *
  29  * Read from an input stream, accepting CR/LF, LF or just CR.
  30  */
  31 public class ReadLineInputStream extends BufferedInputStream
  32 {
  33     boolean _seenCRLF;
  34     boolean _skipLF;
  35
  36     public ReadLineInputStream(InputStream in)
  37     {
  38         super(in);
  39     }
  40
  41     public ReadLineInputStream(InputStream in, int size)
  42     {
  43         super(in,size);
  44     }
  45
  46     public String readLine() throws IOException
  47     {
  48         mark(buf.length);
  49
  50         while (true)
  51         {
  52             int b=super.read();
  53
  54             if (markpos < 0)
  55                 throw new IOException("Buffer size exceeded: no line terminator");
  56
  57             if (b==-1)
  58             {
  59                 int m=markpos;
  60                 markpos=-1;
  61                 if (pos>m)
  62                     return new String(buf,m,pos-m, StandardCharsets.UTF_8);
  63
  64                 return null;
  65             }
  66
  67             if (b=='\r')
  68             {
  69                 int p=pos;
  70
  71                 // if we have seen CRLF before, hungrily consume LF
  72                 if (_seenCRLF && pos<count)
  73                 {
  74                     if (buf[pos]=='\n')
  75                         pos+=1;
  76                 }
  77                 else
  78                     _skipLF=true;
  79                 int m=markpos;
  80                 markpos=-1;
  81                 return new String(buf,m,p-m-1,StandardCharsets.UTF_8);
  82             }
  83
  84             if (b=='\n')
  85             {
  86                 if (_skipLF)
  87                 {
  88                     _skipLF=false;
  89                     _seenCRLF=true;
  90                     markpos++;
  91                     continue;
  92                 }
  93                 int m=markpos;
  94                 markpos=-1;
  95                 return new String(buf,m,pos-m-1,StandardCharsets.UTF_8);
  96             }
  97         }
  98     }
  99
 100     @Override
 101     public synchronized int read() throws IOException
 102     {
 103         int b = super.read();
 104         if (_skipLF)
 105         {
 106             _skipLF=false;
 107             if (_seenCRLF && b=='\n')
 108                 b=super.read();
 109         }
 110         return b;
 111     }
 112
 113     @Override
 114     public synchronized int read(byte[] buf, int off, int len) throws IOException
 115     {
 116         if (_skipLF && len>0)
 117         {
 118             _skipLF=false;
 119             if (_seenCRLF)
 120             {
 121                 int b = super.read();
 122                 if (b==-1)
 123                     return -1;
 124
 125                 if (b!='\n')
 126                 {
 127                     buf[off]=(byte)(0xff&b);
 128                     return 1+super.read(buf,off+1,len-1);
 129                 }
 130             }
 131         }
 132
 133         return super.read(buf,off,len);
 134     }
 135
 136
 137 }