1 /* 2 * Copyright (c) 1995, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.net; 27 28 import java.io.FileDescriptor; 29 import java.io.FileOutputStream; 30 import java.io.IOException; 31 import java.nio.channels.FileChannel; 32 33 /** 34 * This stream extends FileOutputStream to implement a 35 * SocketOutputStream. Note that this class should <b>NOT</b> be 36 * public. 37 * 38 * @author Jonathan Payne 39 * @author Arthur van Hoff 40 */ 41 class SocketOutputStream extends FileOutputStream { 42 static { 43 init(); 44 } 45 46 private AbstractPlainSocketImpl impl = null; 47 private byte temp[] = new byte[1]; 48 private Socket socket = null; 49 50 /** 51 * Creates a new SocketOutputStream. Can only be called 52 * by a Socket. This method needs to hang on to the owner Socket so 53 * that the fd will not be closed. 54 * @param impl the socket output stream implemented 55 */ 56 SocketOutputStream(AbstractPlainSocketImpl impl) throws IOException { 57 super(impl.getFileDescriptor()); 58 this.impl = impl; 59 socket = impl.getSocket(); 60 } 61 62 /** 63 * Returns the unique {@link java.nio.channels.FileChannel FileChannel} 64 * object associated with this file output stream. </p> 65 * 66 * The {@code getChannel} method of {@code SocketOutputStream} 67 * returns {@code null} since it is a socket based stream.</p> 68 * 69 * @return the file channel associated with this file output stream 70 * 71 * @since 1.4 72 * @spec JSR-51 73 */ 74 public final FileChannel getChannel() { 75 return null; 76 } 77 78 /** 79 * Writes to the socket. 80 * @param fd the FileDescriptor 81 * @param b the data to be written 82 * @param off the start offset in the data 83 * @param len the number of bytes that are written 84 * @exception IOException If an I/O error has occurred. 85 */ 86 private native void socketWrite0(FileDescriptor fd, byte[] b, int off, 87 int len) throws IOException; 88 89 /** 90 * Writes to the socket with appropriate locking of the 91 * FileDescriptor. 92 * @param b the data to be written 93 * @param off the start offset in the data 94 * @param len the number of bytes that are written 95 * @exception IOException If an I/O error has occurred. 96 */ 97 private void socketWrite(byte b[], int off, int len) throws IOException { 98 99 100 if (len <= 0 || off < 0 || len > b.length - off) { 101 if (len == 0) { 102 return; 103 } 104 throw new ArrayIndexOutOfBoundsException("len == " + len 105 + " off == " + off + " buffer length == " + b.length); 106 } 107 108 FileDescriptor fd = impl.acquireFD(); 109 try { 110 socketWrite0(fd, b, off, len); 111 } catch (SocketException se) { 112 if (impl.isClosedOrPending()) { 113 throw new SocketException("Socket closed"); 114 } else { 115 throw se; 116 } 117 } finally { 118 impl.releaseFD(); 119 } 120 } 121 122 /** 123 * Writes a byte to the socket. 124 * @param b the data to be written 125 * @exception IOException If an I/O error has occurred. 126 */ 127 public void write(int b) throws IOException { 128 temp[0] = (byte)b; 129 socketWrite(temp, 0, 1); 130 } 131 132 /** 133 * Writes the contents of the buffer <i>b</i> to the socket. 134 * @param b the data to be written 135 * @exception SocketException If an I/O error has occurred. 136 */ 137 public void write(byte b[]) throws IOException { 138 socketWrite(b, 0, b.length); 139 } 140 141 /** 142 * Writes <i>length</i> bytes from buffer <i>b</i> starting at 143 * offset <i>len</i>. 144 * @param b the data to be written 145 * @param off the start offset in the data 146 * @param len the number of bytes that are written 147 * @exception SocketException If an I/O error has occurred. 148 */ 149 public void write(byte b[], int off, int len) throws IOException { 150 socketWrite(b, off, len); 151 } 152 153 /** 154 * Closes the stream. 155 */ 156 private boolean closing = false; 157 public void close() throws IOException { 158 // Prevent recursion. See BugId 4484411 159 if (closing) 160 return; 161 closing = true; 162 if (socket != null) { 163 if (!socket.isClosed()) 164 socket.close(); 165 } else 166 impl.close(); 167 closing = false; 168 } 169 170 /** 171 * Overrides finalize, the fd is closed by the Socket. 172 */ 173 @SuppressWarnings({"deprecation", "removal"}) 174 protected void finalize() {} 175 176 /** 177 * Perform class load-time initializations. 178 */ 179 private static native void init(); 180 181 }