/* |
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* Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package java.io; |
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/** |
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* The <code>DataOutput</code> interface provides |
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* for converting data from any of the Java |
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* primitive types to a series of bytes and |
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* writing these bytes to a binary stream. |
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* There is also a facility for converting |
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* a <code>String</code> into |
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* <a href="DataInput.html#modified-utf-8">modified UTF-8</a> |
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* format and writing the resulting series |
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* of bytes. |
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* <p> |
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* For all the methods in this interface that |
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* write bytes, it is generally true that if |
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* a byte cannot be written for any reason, |
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* an <code>IOException</code> is thrown. |
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* |
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* @author Frank Yellin |
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* @see java.io.DataInput |
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* @see java.io.DataOutputStream |
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* @since JDK1.0 |
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*/ |
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public |
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interface DataOutput { |
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/** |
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* Writes to the output stream the eight |
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* low-order bits of the argument <code>b</code>. |
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* The 24 high-order bits of <code>b</code> |
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* are ignored. |
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* |
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* @param b the byte to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void write(int b) throws IOException; |
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/** |
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* Writes to the output stream all the bytes in array <code>b</code>. |
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* If <code>b</code> is <code>null</code>, |
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* a <code>NullPointerException</code> is thrown. |
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* If <code>b.length</code> is zero, then |
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* no bytes are written. Otherwise, the byte |
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* <code>b[0]</code> is written first, then |
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* <code>b[1]</code>, and so on; the last byte |
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* written is <code>b[b.length-1]</code>. |
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* |
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* @param b the data. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void write(byte b[]) throws IOException; |
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/** |
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* Writes <code>len</code> bytes from array |
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* <code>b</code>, in order, to |
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* the output stream. If <code>b</code> |
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* is <code>null</code>, a <code>NullPointerException</code> |
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* is thrown. If <code>off</code> is negative, |
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* or <code>len</code> is negative, or <code>off+len</code> |
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* is greater than the length of the array |
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* <code>b</code>, then an <code>IndexOutOfBoundsException</code> |
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* is thrown. If <code>len</code> is zero, |
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* then no bytes are written. Otherwise, the |
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* byte <code>b[off]</code> is written first, |
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* then <code>b[off+1]</code>, and so on; the |
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* last byte written is <code>b[off+len-1]</code>. |
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* |
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* @param b the data. |
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* @param off the start offset in the data. |
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* @param len the number of bytes to write. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void write(byte b[], int off, int len) throws IOException; |
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/** |
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* Writes a <code>boolean</code> value to this output stream. |
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* If the argument <code>v</code> |
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* is <code>true</code>, the value <code>(byte)1</code> |
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* is written; if <code>v</code> is <code>false</code>, |
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* the value <code>(byte)0</code> is written. |
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* The byte written by this method may |
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* be read by the <code>readBoolean</code> |
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* method of interface <code>DataInput</code>, |
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* which will then return a <code>boolean</code> |
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* equal to <code>v</code>. |
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* |
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* @param v the boolean to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeBoolean(boolean v) throws IOException; |
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/** |
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* Writes to the output stream the eight low- |
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* order bits of the argument <code>v</code>. |
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* The 24 high-order bits of <code>v</code> |
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* are ignored. (This means that <code>writeByte</code> |
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* does exactly the same thing as <code>write</code> |
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* for an integer argument.) The byte written |
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* by this method may be read by the <code>readByte</code> |
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* method of interface <code>DataInput</code>, |
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* which will then return a <code>byte</code> |
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* equal to <code>(byte)v</code>. |
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* |
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* @param v the byte value to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeByte(int v) throws IOException; |
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/** |
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* Writes two bytes to the output |
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* stream to represent the value of the argument. |
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* The byte values to be written, in the order |
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* shown, are: |
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* <pre>{@code |
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* (byte)(0xff & (v >> 8)) |
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* (byte)(0xff & v) |
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* }</pre> <p> |
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* The bytes written by this method may be |
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* read by the <code>readShort</code> method |
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* of interface <code>DataInput</code> , which |
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* will then return a <code>short</code> equal |
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* to <code>(short)v</code>. |
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* |
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* @param v the <code>short</code> value to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeShort(int v) throws IOException; |
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/** |
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* Writes a <code>char</code> value, which |
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* is comprised of two bytes, to the |
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* output stream. |
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* The byte values to be written, in the order |
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* shown, are: |
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* <pre>{@code |
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* (byte)(0xff & (v >> 8)) |
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* (byte)(0xff & v) |
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* }</pre><p> |
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* The bytes written by this method may be |
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* read by the <code>readChar</code> method |
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* of interface <code>DataInput</code> , which |
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* will then return a <code>char</code> equal |
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* to <code>(char)v</code>. |
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* |
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* @param v the <code>char</code> value to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeChar(int v) throws IOException; |
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/** |
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* Writes an <code>int</code> value, which is |
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* comprised of four bytes, to the output stream. |
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* The byte values to be written, in the order |
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* shown, are: |
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* <pre>{@code |
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* (byte)(0xff & (v >> 24)) |
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* (byte)(0xff & (v >> 16)) |
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* (byte)(0xff & (v >> 8)) |
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* (byte)(0xff & v) |
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* }</pre><p> |
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* The bytes written by this method may be read |
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* by the <code>readInt</code> method of interface |
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* <code>DataInput</code> , which will then |
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* return an <code>int</code> equal to <code>v</code>. |
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* |
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* @param v the <code>int</code> value to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeInt(int v) throws IOException; |
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/** |
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* Writes a <code>long</code> value, which is |
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* comprised of eight bytes, to the output stream. |
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* The byte values to be written, in the order |
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* shown, are: |
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* <pre>{@code |
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* (byte)(0xff & (v >> 56)) |
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* (byte)(0xff & (v >> 48)) |
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* (byte)(0xff & (v >> 40)) |
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* (byte)(0xff & (v >> 32)) |
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* (byte)(0xff & (v >> 24)) |
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* (byte)(0xff & (v >> 16)) |
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* (byte)(0xff & (v >> 8)) |
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* (byte)(0xff & v) |
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* }</pre><p> |
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* The bytes written by this method may be |
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* read by the <code>readLong</code> method |
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* of interface <code>DataInput</code> , which |
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* will then return a <code>long</code> equal |
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* to <code>v</code>. |
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* |
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* @param v the <code>long</code> value to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeLong(long v) throws IOException; |
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/** |
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* Writes a <code>float</code> value, |
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* which is comprised of four bytes, to the output stream. |
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* It does this as if it first converts this |
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* <code>float</code> value to an <code>int</code> |
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* in exactly the manner of the <code>Float.floatToIntBits</code> |
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* method and then writes the <code>int</code> |
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* value in exactly the manner of the <code>writeInt</code> |
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* method. The bytes written by this method |
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* may be read by the <code>readFloat</code> |
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* method of interface <code>DataInput</code>, |
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* which will then return a <code>float</code> |
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* equal to <code>v</code>. |
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* |
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* @param v the <code>float</code> value to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeFloat(float v) throws IOException; |
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/** |
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* Writes a <code>double</code> value, |
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* which is comprised of eight bytes, to the output stream. |
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* It does this as if it first converts this |
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* <code>double</code> value to a <code>long</code> |
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* in exactly the manner of the <code>Double.doubleToLongBits</code> |
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* method and then writes the <code>long</code> |
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* value in exactly the manner of the <code>writeLong</code> |
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* method. The bytes written by this method |
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* may be read by the <code>readDouble</code> |
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* method of interface <code>DataInput</code>, |
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* which will then return a <code>double</code> |
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* equal to <code>v</code>. |
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* |
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* @param v the <code>double</code> value to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeDouble(double v) throws IOException; |
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/** |
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* Writes a string to the output stream. |
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* For every character in the string |
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* <code>s</code>, taken in order, one byte |
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* is written to the output stream. If |
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* <code>s</code> is <code>null</code>, a <code>NullPointerException</code> |
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* is thrown.<p> If <code>s.length</code> |
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* is zero, then no bytes are written. Otherwise, |
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* the character <code>s[0]</code> is written |
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* first, then <code>s[1]</code>, and so on; |
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* the last character written is <code>s[s.length-1]</code>. |
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* For each character, one byte is written, |
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* the low-order byte, in exactly the manner |
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* of the <code>writeByte</code> method . The |
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* high-order eight bits of each character |
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* in the string are ignored. |
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* |
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* @param s the string of bytes to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeBytes(String s) throws IOException; |
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/** |
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* Writes every character in the string <code>s</code>, |
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* to the output stream, in order, |
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* two bytes per character. If <code>s</code> |
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* is <code>null</code>, a <code>NullPointerException</code> |
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* is thrown. If <code>s.length</code> |
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* is zero, then no characters are written. |
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* Otherwise, the character <code>s[0]</code> |
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* is written first, then <code>s[1]</code>, |
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* and so on; the last character written is |
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* <code>s[s.length-1]</code>. For each character, |
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* two bytes are actually written, high-order |
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* byte first, in exactly the manner of the |
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* <code>writeChar</code> method. |
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* |
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* @param s the string value to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeChars(String s) throws IOException; |
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/** |
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* Writes two bytes of length information |
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* to the output stream, followed |
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* by the |
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* <a href="DataInput.html#modified-utf-8">modified UTF-8</a> |
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* representation |
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* of every character in the string <code>s</code>. |
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* If <code>s</code> is <code>null</code>, |
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* a <code>NullPointerException</code> is thrown. |
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* Each character in the string <code>s</code> |
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* is converted to a group of one, two, or |
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* three bytes, depending on the value of the |
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* character.<p> |
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* If a character <code>c</code> |
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* is in the range <code>\u0001</code> through |
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* <code>\u007f</code>, it is represented |
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* by one byte: |
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* <pre>(byte)c </pre> <p> |
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* If a character <code>c</code> is <code>\u0000</code> |
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* or is in the range <code>\u0080</code> |
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* through <code>\u07ff</code>, then it is |
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* represented by two bytes, to be written |
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* in the order shown: <pre>{@code |
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* (byte)(0xc0 | (0x1f & (c >> 6))) |
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* (byte)(0x80 | (0x3f & c)) |
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* }</pre> <p> If a character |
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* <code>c</code> is in the range <code>\u0800</code> |
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* through <code>uffff</code>, then it is |
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* represented by three bytes, to be written |
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* in the order shown: <pre>{@code |
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* (byte)(0xe0 | (0x0f & (c >> 12))) |
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* (byte)(0x80 | (0x3f & (c >> 6))) |
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* (byte)(0x80 | (0x3f & c)) |
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* }</pre> <p> First, |
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* the total number of bytes needed to represent |
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* all the characters of <code>s</code> is |
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* calculated. If this number is larger than |
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* <code>65535</code>, then a <code>UTFDataFormatException</code> |
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* is thrown. Otherwise, this length is written |
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* to the output stream in exactly the manner |
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* of the <code>writeShort</code> method; |
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* after this, the one-, two-, or three-byte |
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* representation of each character in the |
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* string <code>s</code> is written.<p> The |
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* bytes written by this method may be read |
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* by the <code>readUTF</code> method of interface |
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* <code>DataInput</code> , which will then |
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* return a <code>String</code> equal to <code>s</code>. |
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* |
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* @param s the string value to be written. |
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* @throws IOException if an I/O error occurs. |
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*/ |
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void writeUTF(String s) throws IOException; |
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} |