author | erikj |
Tue, 12 Sep 2017 19:03:39 +0200 | |
changeset 47216 | 71c04702a3d5 |
parent 25859 | jdk/src/java.base/share/classes/java/io/DataOutputStream.java@3317bb8137f4 |
child 54309 | c4c225b49c5f |
permissions | -rw-r--r-- |
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/* |
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* Copyright (c) 1994, 2004, 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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* A data output stream lets an application write primitive Java data |
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* types to an output stream in a portable way. An application can |
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* then use a data input stream to read the data back in. |
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* |
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* @author unascribed |
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* @see java.io.DataInputStream |
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24865
09b1d992ca72
8044740: Convert all JDK versions used in @since tag to 1.n[.n] in jdk repo
henryjen
parents:
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diff
changeset
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* @since 1.0 |
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*/ |
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public |
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class DataOutputStream extends FilterOutputStream implements DataOutput { |
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/** |
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* The number of bytes written to the data output stream so far. |
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* If this counter overflows, it will be wrapped to Integer.MAX_VALUE. |
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*/ |
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protected int written; |
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||
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/** |
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* bytearr is initialized on demand by writeUTF |
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*/ |
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private byte[] bytearr = null; |
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/** |
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* Creates a new data output stream to write data to the specified |
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* underlying output stream. The counter <code>written</code> is |
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* set to zero. |
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* |
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* @param out the underlying output stream, to be saved for later |
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* use. |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public DataOutputStream(OutputStream out) { |
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super(out); |
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} |
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/** |
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* Increases the written counter by the specified value |
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* until it reaches Integer.MAX_VALUE. |
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*/ |
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private void incCount(int value) { |
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int temp = written + value; |
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if (temp < 0) { |
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temp = Integer.MAX_VALUE; |
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} |
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written = temp; |
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} |
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/** |
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* Writes the specified byte (the low eight bits of the argument |
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* <code>b</code>) to the underlying output stream. If no exception |
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* is thrown, the counter <code>written</code> is incremented by |
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* <code>1</code>. |
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* <p> |
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* Implements the <code>write</code> method of <code>OutputStream</code>. |
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* |
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* @param b the <code>byte</code> to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public synchronized void write(int b) throws IOException { |
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out.write(b); |
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incCount(1); |
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} |
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/** |
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* Writes <code>len</code> bytes from the specified byte array |
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* starting at offset <code>off</code> to the underlying output stream. |
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* If no exception is thrown, the counter <code>written</code> is |
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* incremented by <code>len</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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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public synchronized void write(byte b[], int off, int len) |
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throws IOException |
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{ |
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out.write(b, off, len); |
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incCount(len); |
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} |
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/** |
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* Flushes this data output stream. This forces any buffered output |
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* bytes to be written out to the stream. |
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* <p> |
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* The <code>flush</code> method of <code>DataOutputStream</code> |
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* calls the <code>flush</code> method of its underlying output stream. |
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* |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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* @see java.io.OutputStream#flush() |
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*/ |
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public void flush() throws IOException { |
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out.flush(); |
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} |
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/** |
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* Writes a <code>boolean</code> to the underlying output stream as |
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* a 1-byte value. The value <code>true</code> is written out as the |
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* value <code>(byte)1</code>; the value <code>false</code> is |
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* written out as the value <code>(byte)0</code>. If no exception is |
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* thrown, the counter <code>written</code> is incremented by |
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* <code>1</code>. |
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* |
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* @param v a <code>boolean</code> value to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public final void writeBoolean(boolean v) throws IOException { |
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out.write(v ? 1 : 0); |
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incCount(1); |
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} |
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/** |
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* Writes out a <code>byte</code> to the underlying output stream as |
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* a 1-byte value. If no exception is thrown, the counter |
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* <code>written</code> is incremented by <code>1</code>. |
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* |
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* @param v a <code>byte</code> value to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public final void writeByte(int v) throws IOException { |
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out.write(v); |
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incCount(1); |
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} |
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/** |
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* Writes a <code>short</code> to the underlying output stream as two |
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* bytes, high byte first. If no exception is thrown, the counter |
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* <code>written</code> is incremented by <code>2</code>. |
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* |
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* @param v a <code>short</code> to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public final void writeShort(int v) throws IOException { |
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out.write((v >>> 8) & 0xFF); |
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out.write((v >>> 0) & 0xFF); |
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incCount(2); |
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} |
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/** |
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* Writes a <code>char</code> to the underlying output stream as a |
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* 2-byte value, high byte first. If no exception is thrown, the |
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* counter <code>written</code> is incremented by <code>2</code>. |
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* |
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* @param v a <code>char</code> value to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public final void writeChar(int v) throws IOException { |
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out.write((v >>> 8) & 0xFF); |
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out.write((v >>> 0) & 0xFF); |
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incCount(2); |
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} |
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/** |
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* Writes an <code>int</code> to the underlying output stream as four |
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* bytes, high byte first. If no exception is thrown, the counter |
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* <code>written</code> is incremented by <code>4</code>. |
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* |
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* @param v an <code>int</code> to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public final void writeInt(int v) throws IOException { |
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out.write((v >>> 24) & 0xFF); |
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out.write((v >>> 16) & 0xFF); |
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out.write((v >>> 8) & 0xFF); |
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out.write((v >>> 0) & 0xFF); |
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incCount(4); |
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} |
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private byte writeBuffer[] = new byte[8]; |
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/** |
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* Writes a <code>long</code> to the underlying output stream as eight |
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* bytes, high byte first. In no exception is thrown, the counter |
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* <code>written</code> is incremented by <code>8</code>. |
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* |
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* @param v a <code>long</code> to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public final void writeLong(long v) throws IOException { |
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writeBuffer[0] = (byte)(v >>> 56); |
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writeBuffer[1] = (byte)(v >>> 48); |
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writeBuffer[2] = (byte)(v >>> 40); |
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writeBuffer[3] = (byte)(v >>> 32); |
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writeBuffer[4] = (byte)(v >>> 24); |
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writeBuffer[5] = (byte)(v >>> 16); |
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writeBuffer[6] = (byte)(v >>> 8); |
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writeBuffer[7] = (byte)(v >>> 0); |
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out.write(writeBuffer, 0, 8); |
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incCount(8); |
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} |
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/** |
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* Converts the float argument to an <code>int</code> using the |
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* <code>floatToIntBits</code> method in class <code>Float</code>, |
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* and then writes that <code>int</code> value to the underlying |
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* output stream as a 4-byte quantity, high byte first. If no |
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* exception is thrown, the counter <code>written</code> is |
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* incremented by <code>4</code>. |
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* |
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* @param v a <code>float</code> value to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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* @see java.lang.Float#floatToIntBits(float) |
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*/ |
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public final void writeFloat(float v) throws IOException { |
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writeInt(Float.floatToIntBits(v)); |
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} |
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/** |
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* Converts the double argument to a <code>long</code> using the |
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* <code>doubleToLongBits</code> method in class <code>Double</code>, |
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* and then writes that <code>long</code> value to the underlying |
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* output stream as an 8-byte quantity, high byte first. If no |
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* exception is thrown, the counter <code>written</code> is |
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* incremented by <code>8</code>. |
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* |
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* @param v a <code>double</code> value to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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* @see java.lang.Double#doubleToLongBits(double) |
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*/ |
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public final void writeDouble(double v) throws IOException { |
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writeLong(Double.doubleToLongBits(v)); |
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} |
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/** |
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* Writes out the string to the underlying output stream as a |
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* sequence of bytes. Each character in the string is written out, in |
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* sequence, by discarding its high eight bits. If no exception is |
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* thrown, the counter <code>written</code> is incremented by the |
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* length of <code>s</code>. |
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* |
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* @param s a string of bytes to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public final void writeBytes(String s) throws IOException { |
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int len = s.length(); |
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for (int i = 0 ; i < len ; i++) { |
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out.write((byte)s.charAt(i)); |
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} |
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incCount(len); |
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} |
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||
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/** |
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* Writes a string to the underlying output stream as a sequence of |
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* characters. Each character is written to the data output stream as |
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* if by the <code>writeChar</code> method. If no exception is |
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* thrown, the counter <code>written</code> is incremented by twice |
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* the length of <code>s</code>. |
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* |
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* @param s a <code>String</code> value to be written. |
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* @exception IOException if an I/O error occurs. |
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* @see java.io.DataOutputStream#writeChar(int) |
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* @see java.io.FilterOutputStream#out |
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*/ |
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public final void writeChars(String s) throws IOException { |
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int len = s.length(); |
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for (int i = 0 ; i < len ; i++) { |
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int v = s.charAt(i); |
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out.write((v >>> 8) & 0xFF); |
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out.write((v >>> 0) & 0xFF); |
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} |
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incCount(len * 2); |
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} |
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||
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/** |
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* Writes a string to the underlying output stream using |
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* <a href="DataInput.html#modified-utf-8">modified UTF-8</a> |
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* encoding in a machine-independent manner. |
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* <p> |
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* First, two bytes are written to the output stream as if by the |
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* <code>writeShort</code> method giving the number of bytes to |
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* follow. This value is the number of bytes actually written out, |
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* not the length of the string. Following the length, each character |
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* of the string is output, in sequence, using the modified UTF-8 encoding |
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* for the character. If no exception is thrown, the counter |
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* <code>written</code> is incremented by the total number of |
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* bytes written to the output stream. This will be at least two |
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* plus the length of <code>str</code>, and at most two plus |
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* thrice the length of <code>str</code>. |
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* |
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* @param str a string to be written. |
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* @exception IOException if an I/O error occurs. |
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*/ |
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322 |
public final void writeUTF(String str) throws IOException { |
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writeUTF(str, this); |
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324 |
} |
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325 |
||
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/** |
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* Writes a string to the specified DataOutput using |
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* <a href="DataInput.html#modified-utf-8">modified UTF-8</a> |
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* encoding in a machine-independent manner. |
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* <p> |
|
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* First, two bytes are written to out as if by the <code>writeShort</code> |
|
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* method giving the number of bytes to follow. This value is the number of |
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* bytes actually written out, not the length of the string. Following the |
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* length, each character of the string is output, in sequence, using the |
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* modified UTF-8 encoding for the character. If no exception is thrown, the |
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* counter <code>written</code> is incremented by the total number of |
|
337 |
* bytes written to the output stream. This will be at least two |
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338 |
* plus the length of <code>str</code>, and at most two plus |
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* thrice the length of <code>str</code>. |
|
340 |
* |
|
341 |
* @param str a string to be written. |
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342 |
* @param out destination to write to |
|
343 |
* @return The number of bytes written out. |
|
344 |
* @exception IOException if an I/O error occurs. |
|
345 |
*/ |
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346 |
static int writeUTF(String str, DataOutput out) throws IOException { |
|
347 |
int strlen = str.length(); |
|
348 |
int utflen = 0; |
|
349 |
int c, count = 0; |
|
350 |
||
351 |
/* use charAt instead of copying String to char array */ |
|
352 |
for (int i = 0; i < strlen; i++) { |
|
353 |
c = str.charAt(i); |
|
354 |
if ((c >= 0x0001) && (c <= 0x007F)) { |
|
355 |
utflen++; |
|
356 |
} else if (c > 0x07FF) { |
|
357 |
utflen += 3; |
|
358 |
} else { |
|
359 |
utflen += 2; |
|
360 |
} |
|
361 |
} |
|
362 |
||
363 |
if (utflen > 65535) |
|
364 |
throw new UTFDataFormatException( |
|
365 |
"encoded string too long: " + utflen + " bytes"); |
|
366 |
||
367 |
byte[] bytearr = null; |
|
368 |
if (out instanceof DataOutputStream) { |
|
369 |
DataOutputStream dos = (DataOutputStream)out; |
|
370 |
if(dos.bytearr == null || (dos.bytearr.length < (utflen+2))) |
|
371 |
dos.bytearr = new byte[(utflen*2) + 2]; |
|
372 |
bytearr = dos.bytearr; |
|
373 |
} else { |
|
374 |
bytearr = new byte[utflen+2]; |
|
375 |
} |
|
376 |
||
377 |
bytearr[count++] = (byte) ((utflen >>> 8) & 0xFF); |
|
378 |
bytearr[count++] = (byte) ((utflen >>> 0) & 0xFF); |
|
379 |
||
380 |
int i=0; |
|
381 |
for (i=0; i<strlen; i++) { |
|
382 |
c = str.charAt(i); |
|
383 |
if (!((c >= 0x0001) && (c <= 0x007F))) break; |
|
384 |
bytearr[count++] = (byte) c; |
|
385 |
} |
|
386 |
||
387 |
for (;i < strlen; i++){ |
|
388 |
c = str.charAt(i); |
|
389 |
if ((c >= 0x0001) && (c <= 0x007F)) { |
|
390 |
bytearr[count++] = (byte) c; |
|
391 |
||
392 |
} else if (c > 0x07FF) { |
|
393 |
bytearr[count++] = (byte) (0xE0 | ((c >> 12) & 0x0F)); |
|
394 |
bytearr[count++] = (byte) (0x80 | ((c >> 6) & 0x3F)); |
|
395 |
bytearr[count++] = (byte) (0x80 | ((c >> 0) & 0x3F)); |
|
396 |
} else { |
|
397 |
bytearr[count++] = (byte) (0xC0 | ((c >> 6) & 0x1F)); |
|
398 |
bytearr[count++] = (byte) (0x80 | ((c >> 0) & 0x3F)); |
|
399 |
} |
|
400 |
} |
|
401 |
out.write(bytearr, 0, utflen+2); |
|
402 |
return utflen + 2; |
|
403 |
} |
|
404 |
||
405 |
/** |
|
406 |
* Returns the current value of the counter <code>written</code>, |
|
407 |
* the number of bytes written to this data output stream so far. |
|
408 |
* If the counter overflows, it will be wrapped to Integer.MAX_VALUE. |
|
409 |
* |
|
410 |
* @return the value of the <code>written</code> field. |
|
411 |
* @see java.io.DataOutputStream#written |
|
412 |
*/ |
|
413 |
public final int size() { |
|
414 |
return written; |
|
415 |
} |
|
416 |
} |