/* * * * Copyright 1990-2009 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER * * This program 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. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License version 2 for more details (a copy is * included at /legal/license.txt). * * You should have received a copy of the GNU General Public License * version 2 along with this work; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa * Clara, CA 95054 or visit www.sun.com if you need additional * information or have any questions. */ package java.io; /** * A data output stream lets an application write primitive Java data * types to an output stream in a portable way. An application can * then use a data input stream to read the data back in. * * @version 12/17/01 (CLDC 1.1) * @see java.io.DataInputStream * @since JDK1.0, CLDC 1.0 */ public class DataOutputStream extends OutputStream implements DataOutput { /** * The output stream. */ protected OutputStream out; /** * Creates a new data output stream to write data to the specified * underlying output stream. * * @param out the underlying output stream, to be saved for later * use. */ public DataOutputStream(OutputStream out) { this.out = out; } /** * Writes the specified byte (the low eight bits of the argument * <code>b</code>) to the underlying output stream. * <p> * Implements the <code>write</code> method of <code>OutputStream</code>. * * @param b the <code>byte</code> to be written. * @exception IOException if an I/O error occurs. */ public void write(int b) throws IOException { out.write(b); } /** * Writes <code>len</code> bytes from the specified byte array * starting at offset <code>off</code> to the underlying output stream. * * @param b the data. * @param off the start offset in the data. * @param len the number of bytes to write. * @exception IOException if an I/O error occurs. */ public void write(byte b[], int off, int len) throws IOException { out.write(b, off, len); } /** * Flushes this data output stream. This forces any buffered output * bytes to be written out to the stream. * <p> * The <code>flush</code> method of <code>DataOutputStream</code> * calls the <code>flush</code> method of its underlying output stream. * * @exception IOException if an I/O error occurs. */ public void flush() throws IOException { out.flush(); } /** * Closes this output stream and releases any system resources * associated with the stream. * <p> * The <code>close</code> method * calls its <code>flush</code> method, and then calls the * <code>close</code> method of its underlying output stream. * * @exception IOException if an I/O error occurs. */ public void close() throws IOException { try { flush(); } catch (IOException e) { } out.close(); } /** * Writes a <code>boolean</code> to the underlying output stream as * a 1-byte value. The value <code>true</code> is written out as the * value <code>(byte)1</code>; the value <code>false</code> is * written out as the value <code>(byte)0</code>. * * @param v a <code>boolean</code> value to be written. * @exception IOException if an I/O error occurs. */ public final void writeBoolean(boolean v) throws IOException { write(v ? 1 : 0); } /** * Writes out a <code>byte</code> to the underlying output stream as * a 1-byte value. * * @param v a <code>byte</code> value to be written. * @exception IOException if an I/O error occurs. */ public final void writeByte(int v) throws IOException { write(v); } /** * Writes a <code>short</code> to the underlying output stream as two * bytes, high byte first. * * @param v a <code>short</code> to be written. * @exception IOException if an I/O error occurs. */ public final void writeShort(int v) throws IOException { write((v >>> 8) & 0xFF); write((v >>> 0) & 0xFF); } /** * Writes a <code>char</code> to the underlying output stream as a * 2-byte value, high byte first. * * @param v a <code>char</code> value to be written. * @exception IOException if an I/O error occurs. */ public final void writeChar(int v) throws IOException { write((v >>> 8) & 0xFF); write((v >>> 0) & 0xFF); } /** * Writes an <code>int</code> to the underlying output stream as four * bytes, high byte first. * * @param v an <code>int</code> to be written. * @exception IOException if an I/O error occurs. */ public final void writeInt(int v) throws IOException { write((v >>> 24) & 0xFF); write((v >>> 16) & 0xFF); write((v >>> 8) & 0xFF); write((v >>> 0) & 0xFF); } /** * Writes a <code>long</code> to the underlying output stream as eight * bytes, high byte first. * * @param v a <code>long</code> to be written. * @exception IOException if an I/O error occurs. */ public final void writeLong(long v) throws IOException { write((int)(v >>> 56) & 0xFF); write((int)(v >>> 48) & 0xFF); write((int)(v >>> 40) & 0xFF); write((int)(v >>> 32) & 0xFF); write((int)(v >>> 24) & 0xFF); write((int)(v >>> 16) & 0xFF); write((int)(v >>> 8) & 0xFF); write((int)(v >>> 0) & 0xFF); } /** * Converts the float argument to an <code>int</code> using the * <code>floatToIntBits</code> method in class <code>Float</code>, * and then writes that <code>int</code> value to the underlying * output stream as a 4-byte quantity, high byte first. * * @param v a <code>float</code> value to be written. * @exception IOException if an I/O error occurs. * @see java.lang.Float#floatToIntBits(float) * @since CLDC 1.1 */ public final void writeFloat(float v) throws IOException { writeInt(Float.floatToIntBits(v)); } /** * Converts the double argument to a <code>long</code> using the * <code>doubleToLongBits</code> method in class <code>Double</code>, * and then writes that <code>long</code> value to the underlying * output stream as an 8-byte quantity, high byte first. * * @param v a <code>double</code> value to be written. * @exception IOException if an I/O error occurs. * @see java.lang.Double#doubleToLongBits(double) * @since CLDC 1.1 */ public final void writeDouble(double v) throws IOException { writeLong(Double.doubleToLongBits(v)); } /** * Writes a string to the underlying output stream as a sequence of * characters. Each character is written to the data output stream as * if by the <code>writeChar</code> method. * * @param s a <code>String</code> value to be written. * @exception IOException if an I/O error occurs. * @see java.io.DataOutputStream#writeChar(int) */ public final void writeChars(String s) throws IOException { int len = s.length(); for (int i = 0 ; i < len ; i++) { int v = s.charAt(i); write((v >>> 8) & 0xFF); write((v >>> 0) & 0xFF); } } /** * Writes a string to the underlying output stream using UTF-8 * encoding in a machine-independent manner. * <p> * First, two bytes are written to the output stream as if by the * <code>writeShort</code> method giving the number of bytes to * follow. This value is the number of bytes actually written out, * not the length of the string. Following the length, each character * of the string is output, in sequence, using the UTF-8 encoding * for the character. * * @param str a string to be written. * @exception IOException if an I/O error occurs. */ public final void writeUTF(String str) throws IOException { writeUTF(str, this); } /** * Writes a string to the specified DataOutput using UTF-8 encoding in a * machine-independent manner. * <p> * First, two bytes are written to out as if by the <code>writeShort</code> * method giving the number of bytes to follow. This value is the number of * bytes actually written out, not the length of the string. Following the * length, each character of the string is output, in sequence, using the * UTF-8 encoding for the character. * * @param str a string to be written. * @param out destination to write to * @return The number of bytes written out. * @exception IOException if an I/O error occurs. */ static final int writeUTF(String str, DataOutput out) throws IOException { int strlen = str.length(); int utflen = 0; char[] charr = new char[strlen]; int c, count = 0; str.getChars(0, strlen, charr, 0); for (int i = 0; i < strlen; i++) { c = charr[i]; if ((c >= 0x0001) && (c <= 0x007F)) { utflen++; } else if (c > 0x07FF) { utflen += 3; } else { utflen += 2; } } if (utflen > 65535) { throw new UTFDataFormatException(); } byte[] bytearr = new byte[utflen+2]; bytearr[count++] = (byte) ((utflen >>> 8) & 0xFF); bytearr[count++] = (byte) ((utflen >>> 0) & 0xFF); for (int i = 0; i < strlen; i++) { c = charr[i]; if ((c >= 0x0001) && (c <= 0x007F)) { bytearr[count++] = (byte) c; } else if (c > 0x07FF) { bytearr[count++] = (byte) (0xE0 | ((c >> 12) & 0x0F)); bytearr[count++] = (byte) (0x80 | ((c >> 6) & 0x3F)); bytearr[count++] = (byte) (0x80 | ((c >> 0) & 0x3F)); } else { bytearr[count++] = (byte) (0xC0 | ((c >> 6) & 0x1F)); bytearr[count++] = (byte) (0x80 | ((c >> 0) & 0x3F)); } } out.write(bytearr); return utflen + 2; } }