src/share/classes/java/io/DataInput.java
Print this page
@@ -1,7 +1,7 @@
/*
- * Copyright (c) 1995, 2006, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1995, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
@@ -24,29 +24,29 @@
*/
package java.io;
/**
- * The <code>DataInput</code> interface provides
+ * The {@code DataInput} interface provides
* for reading bytes from a binary stream and
* reconstructing from them data in any of
* the Java primitive types. There is also
* a
- * facility for reconstructing a <code>String</code>
+ * facility for reconstructing a {@code String}
* from data in
* <a href="#modified-utf-8">modified UTF-8</a>
* format.
* <p>
* It is generally true of all the reading
* routines in this interface that if end of
* file is reached before the desired number
- * of bytes has been read, an <code>EOFException</code>
- * (which is a kind of <code>IOException</code>)
+ * of bytes has been read, an {@code EOFException}
+ * (which is a kind of {@code IOException})
* is thrown. If any byte cannot be read for
- * any reason other than end of file, an <code>IOException</code>
- * other than <code>EOFException</code> is
- * thrown. In particular, an <code>IOException</code>
+ * any reason other than end of file, an {@code IOException}
+ * other than {@code EOFException} is
+ * thrown. In particular, an {@code IOException}
* may be thrown if the input stream has been
* closed.
*
* <h4><a name="modified-utf-8">Modified UTF-8</a></h4>
* <p>
@@ -56,12 +56,12 @@
* <i>3.9 Unicode Encoding Forms</i> of <i>The Unicode Standard, Version
* 4.0</i>).
* Note that in the following tables, the most significant bit appears in the
* far left-hand column.
* <p>
- * All characters in the range <code>'\u0001'</code> to
- * <code>'\u007F'</code> are represented by a single byte:
+ * All characters in the range {@code '\u005Cu0001'} to
+ * {@code '\u005Cu007F'} are represented by a single byte:
*
* <blockquote>
* <table border="1" cellspacing="0" cellpadding="8" width="50%"
* summary="Bit values and bytes">
* <tr>
@@ -81,12 +81,12 @@
* </tr>
* </table>
* </blockquote>
*
* <p>
- * The null character <code>'\u0000'</code> and characters in the
- * range <code>'\u0080'</code> to <code>'\u07FF'</code> are
+ * The null character {@code '\u005Cu0000'} and characters in the
+ * range {@code '\u005Cu0080'} to {@code '\u005Cu07FF'} are
* represented by a pair of bytes:
*
* <blockquote>
* <table border="1" cellspacing="0" cellpadding="8" width="50%"
* summary="Bit values and bytes">
@@ -121,12 +121,12 @@
* </tr>
* </table>
* </blockquote>
*
* <br>
- * <code>char</code> values in the range <code>'\u0800'</code> to
- * <code>'\uFFFF'</code> are represented by three bytes:
+ * {@code char} values in the range {@code '\u005Cu0800'} to
+ * {@code '\u005CuFFFF'} are represented by three bytes:
*
* <blockquote>
* <table border="1" cellspacing="0" cellpadding="8" width="50%"
* summary="Bit values and bytes">
* <tr>
@@ -176,11 +176,11 @@
*
* <p>
* The differences between this format and the
* standard UTF-8 format are the following:
* <ul>
- * <li>The null byte <code>'\u0000'</code> is encoded in 2-byte format
+ * <li>The null byte {@code '\u005Cu0000'} is encoded in 2-byte format
* rather than 1-byte, so that the encoded strings never have
* embedded nulls.
* <li>Only the 1-byte, 2-byte, and 3-byte formats are used.
* <li><a href="../lang/Character.html#unicode">Supplementary characters</a>
* are represented in the form of surrogate pairs.
@@ -193,40 +193,40 @@
public
interface DataInput {
/**
* Reads some bytes from an input
* stream and stores them into the buffer
- * array <code>b</code>. The number of bytes
+ * array {@code b}. The number of bytes
* read is equal
- * to the length of <code>b</code>.
+ * to the length of {@code b}.
* <p>
* This method blocks until one of the
* following conditions occurs:<p>
* <ul>
- * <li><code>b.length</code>
+ * <li>{@code b.length}
* bytes of input data are available, in which
* case a normal return is made.
*
* <li>End of
- * file is detected, in which case an <code>EOFException</code>
+ * file is detected, in which case an {@code EOFException}
* is thrown.
*
* <li>An I/O error occurs, in
- * which case an <code>IOException</code> other
- * than <code>EOFException</code> is thrown.
+ * which case an {@code IOException} other
+ * than {@code EOFException} is thrown.
* </ul>
* <p>
- * If <code>b</code> is <code>null</code>,
- * a <code>NullPointerException</code> is thrown.
- * If <code>b.length</code> is zero, then
+ * If {@code b} is {@code null},
+ * a {@code NullPointerException} is thrown.
+ * If {@code b.length} is zero, then
* no bytes are read. Otherwise, the first
- * byte read is stored into element <code>b[0]</code>,
- * the next one into <code>b[1]</code>, and
+ * byte read is stored into element {@code b[0]},
+ * the next one into {@code b[1]}, and
* so on.
* If an exception is thrown from
* this method, then it may be that some but
- * not all bytes of <code>b</code> have been
+ * not all bytes of {@code b} have been
* updated with data from the input stream.
*
* @param b the buffer into which the data is read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
@@ -234,44 +234,44 @@
*/
void readFully(byte b[]) throws IOException;
/**
*
- * Reads <code>len</code>
+ * Reads {@code len}
* bytes from
* an input stream.
* <p>
* This method
* blocks until one of the following conditions
* occurs:<p>
* <ul>
- * <li><code>len</code> bytes
+ * <li>{@code len} bytes
* of input data are available, in which case
* a normal return is made.
*
* <li>End of file
- * is detected, in which case an <code>EOFException</code>
+ * is detected, in which case an {@code EOFException}
* is thrown.
*
* <li>An I/O error occurs, in
- * which case an <code>IOException</code> other
- * than <code>EOFException</code> is thrown.
+ * which case an {@code IOException} other
+ * than {@code EOFException} is thrown.
* </ul>
* <p>
- * If <code>b</code> is <code>null</code>,
- * a <code>NullPointerException</code> is thrown.
- * If <code>off</code> is negative, or <code>len</code>
- * is negative, or <code>off+len</code> is
- * greater than the length of the array <code>b</code>,
- * then an <code>IndexOutOfBoundsException</code>
+ * If {@code b} is {@code null},
+ * a {@code NullPointerException} is thrown.
+ * If {@code off} is negative, or {@code len}
+ * is negative, or {@code off+len} is
+ * greater than the length of the array {@code b},
+ * then an {@code IndexOutOfBoundsException}
* is thrown.
- * If <code>len</code> is zero,
+ * If {@code len} is zero,
* then no bytes are read. Otherwise, the first
- * byte read is stored into element <code>b[off]</code>,
- * the next one into <code>b[off+1]</code>,
+ * byte read is stored into element {@code b[off]},
+ * the next one into {@code b[off+1]},
* and so on. The number of bytes read is,
- * at most, equal to <code>len</code>.
+ * at most, equal to {@code len}.
*
* @param b the buffer into which the data is read.
* @param off an int specifying the offset into the data.
* @param len an int specifying the number of bytes to read.
* @exception EOFException if this stream reaches the end before reading
@@ -280,22 +280,22 @@
*/
void readFully(byte b[], int off, int len) throws IOException;
/**
* Makes an attempt to skip over
- * <code>n</code> bytes
+ * {@code n} bytes
* of data from the input
* stream, discarding the skipped bytes. However,
* it may skip
* over some smaller number of
* bytes, possibly zero. This may result from
* any of a
* number of conditions; reaching
- * end of file before <code>n</code> bytes
+ * end of file before {@code n} bytes
* have been skipped is
* only one possibility.
- * This method never throws an <code>EOFException</code>.
+ * This method never throws an {@code EOFException}.
* The actual
* number of bytes skipped is returned.
*
* @param n the number of bytes to be skipped.
* @return the number of bytes actually skipped.
@@ -303,149 +303,148 @@
*/
int skipBytes(int n) throws IOException;
/**
* Reads one input byte and returns
- * <code>true</code> if that byte is nonzero,
- * <code>false</code> if that byte is zero.
+ * {@code true} if that byte is nonzero,
+ * {@code false} if that byte is zero.
* This method is suitable for reading
- * the byte written by the <code>writeBoolean</code>
- * method of interface <code>DataOutput</code>.
+ * the byte written by the {@code writeBoolean}
+ * method of interface {@code DataOutput}.
*
- * @return the <code>boolean</code> value read.
+ * @return the {@code boolean} value read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
* @exception IOException if an I/O error occurs.
*/
boolean readBoolean() throws IOException;
/**
* Reads and returns one input byte.
* The byte is treated as a signed value in
- * the range <code>-128</code> through <code>127</code>,
+ * the range {@code -128} through {@code 127},
* inclusive.
* This method is suitable for
- * reading the byte written by the <code>writeByte</code>
- * method of interface <code>DataOutput</code>.
+ * reading the byte written by the {@code writeByte}
+ * method of interface {@code DataOutput}.
*
* @return the 8-bit value read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
* @exception IOException if an I/O error occurs.
*/
byte readByte() throws IOException;
/**
* Reads one input byte, zero-extends
- * it to type <code>int</code>, and returns
+ * it to type {@code int}, and returns
* the result, which is therefore in the range
- * <code>0</code>
- * through <code>255</code>.
+ * {@code 0}
+ * through {@code 255}.
* This method is suitable for reading
- * the byte written by the <code>writeByte</code>
- * method of interface <code>DataOutput</code>
- * if the argument to <code>writeByte</code>
+ * the byte written by the {@code writeByte}
+ * method of interface {@code DataOutput}
+ * if the argument to {@code writeByte}
* was intended to be a value in the range
- * <code>0</code> through <code>255</code>.
+ * {@code 0} through {@code 255}.
*
* @return the unsigned 8-bit value read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
* @exception IOException if an I/O error occurs.
*/
int readUnsignedByte() throws IOException;
/**
* Reads two input bytes and returns
- * a <code>short</code> value. Let <code>a</code>
- * be the first byte read and <code>b</code>
+ * a {@code short} value. Let {@code a}
+ * be the first byte read and {@code b}
* be the second byte. The value
* returned
* is:
* <p><pre><code>(short)((a << 8) | (b & 0xff))
* </code></pre>
* This method
* is suitable for reading the bytes written
- * by the <code>writeShort</code> method of
- * interface <code>DataOutput</code>.
+ * by the {@code writeShort} method of
+ * interface {@code DataOutput}.
*
* @return the 16-bit value read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
* @exception IOException if an I/O error occurs.
*/
short readShort() throws IOException;
/**
* Reads two input bytes and returns
- * an <code>int</code> value in the range <code>0</code>
- * through <code>65535</code>. Let <code>a</code>
+ * an {@code int} value in the range {@code 0}
+ * through {@code 65535}. Let {@code a}
* be the first byte read and
- * <code>b</code>
+ * {@code b}
* be the second byte. The value returned is:
* <p><pre><code>(((a & 0xff) << 8) | (b & 0xff))
* </code></pre>
* This method is suitable for reading the bytes
- * written by the <code>writeShort</code> method
- * of interface <code>DataOutput</code> if
- * the argument to <code>writeShort</code>
+ * written by the {@code writeShort} method
+ * of interface {@code DataOutput} if
+ * the argument to {@code writeShort}
* was intended to be a value in the range
- * <code>0</code> through <code>65535</code>.
+ * {@code 0} through {@code 65535}.
*
* @return the unsigned 16-bit value read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
* @exception IOException if an I/O error occurs.
*/
int readUnsignedShort() throws IOException;
/**
- * Reads two input bytes and returns a <code>char</code> value.
- * Let <code>a</code>
- * be the first byte read and <code>b</code>
+ * Reads two input bytes and returns a {@code char} value.
+ * Let {@code a}
+ * be the first byte read and {@code b}
* be the second byte. The value
* returned is:
* <p><pre><code>(char)((a << 8) | (b & 0xff))
* </code></pre>
* This method
* is suitable for reading bytes written by
- * the <code>writeChar</code> method of interface
- * <code>DataOutput</code>.
+ * the {@code writeChar} method of interface
+ * {@code DataOutput}.
*
- * @return the <code>char</code> value read.
+ * @return the {@code char} value read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
* @exception IOException if an I/O error occurs.
*/
char readChar() throws IOException;
/**
* Reads four input bytes and returns an
- * <code>int</code> value. Let <code>a-d</code>
+ * {@code int} value. Let {@code a-d}
* be the first through fourth bytes read. The value returned is:
- * <p><pre>
- * <code>
+ * <p><pre><code>
* (((a & 0xff) << 24) | ((b & 0xff) << 16) |
*  ((c & 0xff) << 8) | (d & 0xff))
* </code></pre>
* This method is suitable
- * for reading bytes written by the <code>writeInt</code>
- * method of interface <code>DataOutput</code>.
+ * for reading bytes written by the {@code writeInt}
+ * method of interface {@code DataOutput}.
*
- * @return the <code>int</code> value read.
+ * @return the {@code int} value read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
* @exception IOException if an I/O error occurs.
*/
int readInt() throws IOException;
/**
* Reads eight input bytes and returns
- * a <code>long</code> value. Let <code>a-h</code>
+ * a {@code long} value. Let {@code a-h}
* be the first through eighth bytes read.
* The value returned is:
- * <p><pre> <code>
+ * <p><pre><code>
* (((long)(a & 0xff) << 56) |
* ((long)(b & 0xff) << 48) |
* ((long)(c & 0xff) << 40) |
* ((long)(d & 0xff) << 32) |
* ((long)(e & 0xff) << 24) |
@@ -453,54 +452,54 @@
* ((long)(g & 0xff) << 8) |
* ((long)(h & 0xff)))
* </code></pre>
* <p>
* This method is suitable
- * for reading bytes written by the <code>writeLong</code>
- * method of interface <code>DataOutput</code>.
+ * for reading bytes written by the {@code writeLong}
+ * method of interface {@code DataOutput}.
*
- * @return the <code>long</code> value read.
+ * @return the {@code long} value read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
* @exception IOException if an I/O error occurs.
*/
long readLong() throws IOException;
/**
* Reads four input bytes and returns
- * a <code>float</code> value. It does this
- * by first constructing an <code>int</code>
+ * a {@code float} value. It does this
+ * by first constructing an {@code int}
* value in exactly the manner
- * of the <code>readInt</code>
- * method, then converting this <code>int</code>
- * value to a <code>float</code> in
- * exactly the manner of the method <code>Float.intBitsToFloat</code>.
+ * of the {@code readInt}
+ * method, then converting this {@code int}
+ * value to a {@code float} in
+ * exactly the manner of the method {@code Float.intBitsToFloat}.
* This method is suitable for reading
- * bytes written by the <code>writeFloat</code>
- * method of interface <code>DataOutput</code>.
+ * bytes written by the {@code writeFloat}
+ * method of interface {@code DataOutput}.
*
- * @return the <code>float</code> value read.
+ * @return the {@code float} value read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
* @exception IOException if an I/O error occurs.
*/
float readFloat() throws IOException;
/**
* Reads eight input bytes and returns
- * a <code>double</code> value. It does this
- * by first constructing a <code>long</code>
+ * a {@code double} value. It does this
+ * by first constructing a {@code long}
* value in exactly the manner
- * of the <code>readlong</code>
- * method, then converting this <code>long</code>
- * value to a <code>double</code> in exactly
- * the manner of the method <code>Double.longBitsToDouble</code>.
+ * of the {@code readlong}
+ * method, then converting this {@code long}
+ * value to a {@code double} in exactly
+ * the manner of the method {@code Double.longBitsToDouble}.
* This method is suitable for reading
- * bytes written by the <code>writeDouble</code>
- * method of interface <code>DataOutput</code>.
+ * bytes written by the {@code writeDouble}
+ * method of interface {@code DataOutput}.
*
- * @return the <code>double</code> value read.
+ * @return the {@code double} value read.
* @exception EOFException if this stream reaches the end before reading
* all the bytes.
* @exception IOException if an I/O error occurs.
*/
double readDouble() throws IOException;
@@ -510,57 +509,57 @@
* It reads successive bytes, converting
* each byte separately into a character,
* until it encounters a line terminator or
* end of
* file; the characters read are then
- * returned as a <code>String</code>. Note
+ * returned as a {@code String}. Note
* that because this
* method processes bytes,
* it does not support input of the full Unicode
* character set.
* <p>
* If end of file is encountered
- * before even one byte can be read, then <code>null</code>
+ * before even one byte can be read, then {@code null}
* is returned. Otherwise, each byte that is
- * read is converted to type <code>char</code>
- * by zero-extension. If the character <code>'\n'</code>
+ * read is converted to type {@code char}
+ * by zero-extension. If the character {@code '\n'}
* is encountered, it is discarded and reading
- * ceases. If the character <code>'\r'</code>
+ * ceases. If the character {@code '\r'}
* is encountered, it is discarded and, if
* the following byte converts  to the
- * character <code>'\n'</code>, then that is
+ * character {@code '\n'}, then that is
* discarded also; reading then ceases. If
* end of file is encountered before either
- * of the characters <code>'\n'</code> and
- * <code>'\r'</code> is encountered, reading
- * ceases. Once reading has ceased, a <code>String</code>
+ * of the characters {@code '\n'} and
+ * {@code '\r'} is encountered, reading
+ * ceases. Once reading has ceased, a {@code String}
* is returned that contains all the characters
* read and not discarded, taken in order.
* Note that every character in this string
- * will have a value less than <code>\u0100</code>,
- * that is, <code>(char)256</code>.
+ * will have a value less than {@code \u005Cu0100},
+ * that is, {@code (char)256}.
*
* @return the next line of text from the input stream,
- * or <CODE>null</CODE> if the end of file is
+ * or {@code null} if the end of file is
* encountered before a byte can be read.
* @exception IOException if an I/O error occurs.
*/
String readLine() throws IOException;
/**
* Reads in a string that has been encoded using a
* <a href="#modified-utf-8">modified UTF-8</a>
* format.
- * The general contract of <code>readUTF</code>
+ * The general contract of {@code readUTF}
* is that it reads a representation of a Unicode
* character string encoded in modified
* UTF-8 format; this string of characters
- * is then returned as a <code>String</code>.
+ * is then returned as a {@code String}.
* <p>
* First, two bytes are read and used to
* construct an unsigned 16-bit integer in
- * exactly the manner of the <code>readUnsignedShort</code>
+ * exactly the manner of the {@code readUnsignedShort}
* method . This integer value is called the
* <i>UTF length</i> and specifies the number
* of additional bytes to be read. These bytes
* are then converted to characters by considering
* them in groups. The length of each group
@@ -568,62 +567,62 @@
* byte of the group. The byte following a
* group, if any, is the first byte of the
* next group.
* <p>
* If the first byte of a group
- * matches the bit pattern <code>0xxxxxxx</code>
- * (where <code>x</code> means "may be <code>0</code>
- * or <code>1</code>"), then the group consists
+ * matches the bit pattern {@code 0xxxxxxx}
+ * (where {@code x} means "may be {@code 0}
+ * or {@code 1}"), then the group consists
* of just that byte. The byte is zero-extended
* to form a character.
* <p>
* If the first byte
- * of a group matches the bit pattern <code>110xxxxx</code>,
- * then the group consists of that byte <code>a</code>
- * and a second byte <code>b</code>. If there
- * is no byte <code>b</code> (because byte
- * <code>a</code> was the last of the bytes
- * to be read), or if byte <code>b</code> does
- * not match the bit pattern <code>10xxxxxx</code>,
- * then a <code>UTFDataFormatException</code>
+ * of a group matches the bit pattern {@code 110xxxxx},
+ * then the group consists of that byte {@code a}
+ * and a second byte {@code b}. If there
+ * is no byte {@code b} (because byte
+ * {@code a} was the last of the bytes
+ * to be read), or if byte {@code b} does
+ * not match the bit pattern {@code 10xxxxxx},
+ * then a {@code UTFDataFormatException}
* is thrown. Otherwise, the group is converted
* to the character:<p>
* <pre><code>(char)(((a& 0x1F) << 6) | (b & 0x3F))
* </code></pre>
* If the first byte of a group
- * matches the bit pattern <code>1110xxxx</code>,
- * then the group consists of that byte <code>a</code>
- * and two more bytes <code>b</code> and <code>c</code>.
- * If there is no byte <code>c</code> (because
- * byte <code>a</code> was one of the last
+ * matches the bit pattern {@code 1110xxxx},
+ * then the group consists of that byte {@code a}
+ * and two more bytes {@code b} and {@code c}.
+ * If there is no byte {@code c} (because
+ * byte {@code a} was one of the last
* two of the bytes to be read), or either
- * byte <code>b</code> or byte <code>c</code>
- * does not match the bit pattern <code>10xxxxxx</code>,
- * then a <code>UTFDataFormatException</code>
+ * byte {@code b} or byte {@code c}
+ * does not match the bit pattern {@code 10xxxxxx},
+ * then a {@code UTFDataFormatException}
* is thrown. Otherwise, the group is converted
* to the character:<p>
* <pre><code>
* (char)(((a & 0x0F) << 12) | ((b & 0x3F) << 6) | (c & 0x3F))
* </code></pre>
* If the first byte of a group matches the
- * pattern <code>1111xxxx</code> or the pattern
- * <code>10xxxxxx</code>, then a <code>UTFDataFormatException</code>
+ * pattern {@code 1111xxxx} or the pattern
+ * {@code 10xxxxxx}, then a {@code UTFDataFormatException}
* is thrown.
* <p>
* If end of file is encountered
* at any time during this entire process,
- * then an <code>EOFException</code> is thrown.
+ * then an {@code EOFException} is thrown.
* <p>
* After every group has been converted to
* a character by this process, the characters
* are gathered, in the same order in which
* their corresponding groups were read from
- * the input stream, to form a <code>String</code>,
+ * the input stream, to form a {@code String},
* which is returned.
* <p>
- * The <code>writeUTF</code>
- * method of interface <code>DataOutput</code>
+ * The {@code writeUTF}
+ * method of interface {@code DataOutput}
* may be used to write data that is suitable
* for reading by this method.
* @return a Unicode string.
* @exception EOFException if this stream reaches the end
* before reading all the bytes.