290 lines
8.2 KiB
Java
290 lines
8.2 KiB
Java
/* Copyright (C) 1998, 1999 Red Hat, Inc.
|
|
|
|
This file is part of libgcj.
|
|
|
|
This software is copyrighted work licensed under the terms of the
|
|
Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
|
|
details. */
|
|
|
|
package java.io;
|
|
|
|
/**
|
|
* @author Warren Levy <warrenl@cygnus.com>
|
|
* @date October 20, 1998.
|
|
*/
|
|
|
|
/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
|
|
* "The Java Language Specification", ISBN 0-201-63451-1
|
|
* plus online API docs for JDK 1.2 beta from http://www.javasoft.com.
|
|
* Status: Believed complete and correct.
|
|
*/
|
|
|
|
public class DataInputStream extends FilterInputStream implements DataInput
|
|
{
|
|
// readLine() hack to ensure that an '\r' not followed by an '\n' is
|
|
// handled correctly. If set, readLine() will ignore the first char it sees
|
|
// if that char is a '\n'
|
|
boolean ignoreInitialNewline = false;
|
|
|
|
public DataInputStream(InputStream in)
|
|
{
|
|
super(in);
|
|
}
|
|
|
|
public final int read(byte[] b) throws IOException
|
|
{
|
|
return super.read(b, 0, b.length);
|
|
}
|
|
|
|
public final int read(byte[] b, int off, int len) throws IOException
|
|
{
|
|
if (off < 0 || len < 0 || off + len > b.length)
|
|
throw new ArrayIndexOutOfBoundsException();
|
|
|
|
return super.read(b, off, len);
|
|
}
|
|
|
|
public final boolean readBoolean() throws IOException
|
|
{
|
|
return (readByte() != 0);
|
|
}
|
|
|
|
public final byte readByte() throws IOException
|
|
{
|
|
int i = read();
|
|
if (i < 0)
|
|
throw new EOFException();
|
|
|
|
return (byte) i;
|
|
}
|
|
|
|
public final char readChar() throws IOException
|
|
{
|
|
return (char) ((readByte() << 8) | readUnsignedByte());
|
|
}
|
|
|
|
public final double readDouble() throws IOException
|
|
{
|
|
return Double.longBitsToDouble(readLong());
|
|
}
|
|
|
|
public final float readFloat() throws IOException
|
|
{
|
|
return Float.intBitsToFloat(readInt());
|
|
}
|
|
|
|
public final void readFully(byte[] b) throws IOException
|
|
{
|
|
readFully(b, 0, b.length);
|
|
}
|
|
|
|
public final void readFully(byte[] b, int off, int len) throws IOException
|
|
{
|
|
if (off < 0 || len < 0 || off + len > b.length)
|
|
throw new ArrayIndexOutOfBoundsException();
|
|
|
|
while (len > 0)
|
|
{
|
|
// super.read will block until some data is available.
|
|
int numread = super.read(b, off, len);
|
|
if (numread < 0)
|
|
throw new EOFException();
|
|
len -= numread;
|
|
off += numread;
|
|
}
|
|
}
|
|
|
|
public final int readInt() throws IOException
|
|
{
|
|
int retval = 0;
|
|
for (int i = 0; i < 4; i++)
|
|
retval |= readUnsignedByte() << (24 - i * 8);
|
|
|
|
return retval;
|
|
}
|
|
|
|
// Deprecated as of JDK 1.1
|
|
public final String readLine() throws IOException
|
|
{
|
|
StringBuffer strb = new StringBuffer();
|
|
|
|
readloop: while (true)
|
|
{
|
|
int c = 0;
|
|
char ch = ' ';
|
|
boolean getnext = true;
|
|
while (getnext)
|
|
{
|
|
getnext = false;
|
|
c = read();
|
|
if (c < 0) // got an EOF
|
|
return strb.length() > 0 ? strb.toString() : null;
|
|
ch = (char) c;
|
|
if ((ch &= 0xFF) == '\n')
|
|
// hack to correctly handle '\r\n' sequences
|
|
if (ignoreInitialNewline)
|
|
{
|
|
ignoreInitialNewline = false;
|
|
getnext = true;
|
|
}
|
|
else
|
|
break readloop;
|
|
}
|
|
|
|
if (ch == '\r')
|
|
{
|
|
// FIXME: The following code tries to adjust the stream back one
|
|
// character if the next char read is '\n'. As a last resort,
|
|
// it tries to mark the position before reading but the bottom
|
|
// line is that it is possible that this method will not properly
|
|
// deal with a '\r' '\n' combination thus not fulfilling the
|
|
// DataInput contract for readLine. It's not a particularly
|
|
// safe approach threadwise since it is unsynchronized and
|
|
// since it might mark an input stream behind the users back.
|
|
// Along the same vein it could try the same thing for
|
|
// ByteArrayInputStream and PushbackInputStream, but that is
|
|
// probably overkill since this is deprecated & BufferedInputStream
|
|
// is the most likely type of input stream.
|
|
//
|
|
// The alternative is to somehow push back the next byte if it
|
|
// isn't a '\n' or to have the reading methods of this class
|
|
// keep track of whether the last byte read was '\r' by readLine
|
|
// and then skip the very next byte if it is '\n'. Either way,
|
|
// this would increase the complexity of the non-deprecated methods
|
|
// and since it is undesirable to make non-deprecated methods
|
|
// less efficient, the following seems like the most reasonable
|
|
// approach.
|
|
int next_c = 0;
|
|
char next_ch = ' ';
|
|
if (in instanceof BufferedInputStream)
|
|
{
|
|
next_c = read();
|
|
next_ch = (char) (next_c & 0xFF);
|
|
if ((next_ch != '\n') && (next_c >= 0))
|
|
{
|
|
BufferedInputStream bin = (BufferedInputStream) in;
|
|
if (bin.pos > 0)
|
|
bin.pos--;
|
|
}
|
|
}
|
|
else if (markSupported())
|
|
{
|
|
next_c = read();
|
|
next_ch = (char) (next_c & 0xFF);
|
|
if ((next_ch != '\n') && (next_c >= 0))
|
|
{
|
|
mark(1);
|
|
if ((read() & 0xFF) != '\n')
|
|
reset();
|
|
}
|
|
}
|
|
// In order to catch cases where 'in' isn't a BufferedInputStream
|
|
// and doesn't support mark() (such as reading from a Socket), set
|
|
// a flag that instructs readLine() to ignore the first character
|
|
// it sees _if_ that character is a '\n'.
|
|
else ignoreInitialNewline = true;
|
|
break;
|
|
}
|
|
strb.append(ch);
|
|
}
|
|
|
|
return strb.length() > 0 ? strb.toString() : "";
|
|
}
|
|
|
|
public final long readLong() throws IOException
|
|
{
|
|
long retval = 0L;
|
|
for (int i = 0; i < 8; i++)
|
|
retval |= (long) readUnsignedByte() << (56 - i * 8);
|
|
|
|
return retval;
|
|
}
|
|
|
|
public final short readShort() throws IOException
|
|
{
|
|
return (short) ((readByte() << 8) | readUnsignedByte());
|
|
}
|
|
|
|
public final int readUnsignedByte() throws IOException
|
|
{
|
|
int i = read();
|
|
if (i < 0)
|
|
throw new EOFException();
|
|
|
|
return (i & 0xFF);
|
|
}
|
|
|
|
public final int readUnsignedShort() throws IOException
|
|
{
|
|
return (readUnsignedByte() << 8) | readUnsignedByte();
|
|
}
|
|
|
|
public final String readUTF() throws IOException
|
|
{
|
|
return readUTF(this);
|
|
}
|
|
|
|
public final static String readUTF(DataInput in) throws IOException
|
|
{
|
|
final int UTFlen = in.readUnsignedShort();
|
|
byte[] buf = new byte[UTFlen];
|
|
StringBuffer strbuf = new StringBuffer();
|
|
|
|
// This blocks until the entire string is available rather than
|
|
// doing partial processing on the bytes that are available and then
|
|
// blocking. An advantage of the latter is that Exceptions
|
|
// could be thrown earlier. The former is a bit cleaner.
|
|
in.readFully(buf, 0, UTFlen);
|
|
for (int i = 0; i < UTFlen; )
|
|
{
|
|
if ((buf[i] & 0x80) == 0) // bit pattern 0xxxxxxx
|
|
strbuf.append((char) (buf[i++] & 0xFF));
|
|
else if ((buf[i] & 0xE0) == 0xC0) // bit pattern 110xxxxx
|
|
{
|
|
if (i + 1 >= UTFlen || (buf[i+1] & 0xC0) != 0x80)
|
|
throw new UTFDataFormatException();
|
|
|
|
strbuf.append((char) (((buf[i++] & 0x1F) << 6) |
|
|
(buf[i++] & 0x3F)));
|
|
}
|
|
else if ((buf[i] & 0xF0) == 0xE0) // bit pattern 1110xxxx
|
|
{
|
|
if (i + 2 >= UTFlen ||
|
|
(buf[i+1] & 0xC0) != 0x80 || (buf[i+2] & 0xC0) != 0x80)
|
|
throw new UTFDataFormatException();
|
|
|
|
strbuf.append((char) (((buf[i++] & 0x0F) << 12) |
|
|
((buf[i++] & 0x3F) << 6) |
|
|
(buf[i++] & 0x3F)));
|
|
}
|
|
else // must be ((buf[i] & 0xF0) == 0xF0 || (buf[i] & 0xC0) == 0x80)
|
|
throw new UTFDataFormatException(); // bit patterns 1111xxxx or
|
|
// 10xxxxxx
|
|
}
|
|
|
|
return strbuf.toString();
|
|
}
|
|
|
|
public final int skipBytes(int n) throws IOException
|
|
{
|
|
// The contract in the Java Lang. Spec. says that this never
|
|
// throws an EOFException and infers that it doesn't block (since
|
|
// it may skip less than the requested number of bytes).
|
|
// BUT, the JCL book specifically says that this method blocks
|
|
// and can throw an EOFException. Finally, the Java 1.2 online
|
|
// doc simply refers to the general contract. As such, we will
|
|
// stick to the contract and assume for now that the JCL book
|
|
// is incorrect.
|
|
|
|
// Since we're only skipping at most an int number of bytes, the cast
|
|
// of return value to an int is fine.
|
|
if (n > 0)
|
|
{
|
|
n = Math.min(n, available());
|
|
return (int) super.skip((long) n);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
}
|