1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/rt/emul/compact/src/main/java/java/io/StringReader.java Tue Jan 17 07:04:06 2017 +0100
1.3 @@ -0,0 +1,201 @@
1.4 +/*
1.5 + * Copyright (c) 1996, 2005, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package java.io;
1.30 +
1.31 +
1.32 +/**
1.33 + * A character stream whose source is a string.
1.34 + *
1.35 + * @author Mark Reinhold
1.36 + * @since JDK1.1
1.37 + */
1.38 +
1.39 +public class StringReader extends Reader {
1.40 +
1.41 + private String str;
1.42 + private int length;
1.43 + private int next = 0;
1.44 + private int mark = 0;
1.45 +
1.46 + /**
1.47 + * Creates a new string reader.
1.48 + *
1.49 + * @param s String providing the character stream.
1.50 + */
1.51 + public StringReader(String s) {
1.52 + this.str = s;
1.53 + this.length = s.length();
1.54 + }
1.55 +
1.56 + /** Check to make sure that the stream has not been closed */
1.57 + private void ensureOpen() throws IOException {
1.58 + if (str == null)
1.59 + throw new IOException("Stream closed");
1.60 + }
1.61 +
1.62 + /**
1.63 + * Reads a single character.
1.64 + *
1.65 + * @return The character read, or -1 if the end of the stream has been
1.66 + * reached
1.67 + *
1.68 + * @exception IOException If an I/O error occurs
1.69 + */
1.70 + public int read() throws IOException {
1.71 + synchronized (lock) {
1.72 + ensureOpen();
1.73 + if (next >= length)
1.74 + return -1;
1.75 + return str.charAt(next++);
1.76 + }
1.77 + }
1.78 +
1.79 + /**
1.80 + * Reads characters into a portion of an array.
1.81 + *
1.82 + * @param cbuf Destination buffer
1.83 + * @param off Offset at which to start writing characters
1.84 + * @param len Maximum number of characters to read
1.85 + *
1.86 + * @return The number of characters read, or -1 if the end of the
1.87 + * stream has been reached
1.88 + *
1.89 + * @exception IOException If an I/O error occurs
1.90 + */
1.91 + public int read(char cbuf[], int off, int len) throws IOException {
1.92 + synchronized (lock) {
1.93 + ensureOpen();
1.94 + if ((off < 0) || (off > cbuf.length) || (len < 0) ||
1.95 + ((off + len) > cbuf.length) || ((off + len) < 0)) {
1.96 + throw new IndexOutOfBoundsException();
1.97 + } else if (len == 0) {
1.98 + return 0;
1.99 + }
1.100 + if (next >= length)
1.101 + return -1;
1.102 + int n = Math.min(length - next, len);
1.103 + str.getChars(next, next + n, cbuf, off);
1.104 + next += n;
1.105 + return n;
1.106 + }
1.107 + }
1.108 +
1.109 + /**
1.110 + * Skips the specified number of characters in the stream. Returns
1.111 + * the number of characters that were skipped.
1.112 + *
1.113 + * <p>The <code>ns</code> parameter may be negative, even though the
1.114 + * <code>skip</code> method of the {@link Reader} superclass throws
1.115 + * an exception in this case. Negative values of <code>ns</code> cause the
1.116 + * stream to skip backwards. Negative return values indicate a skip
1.117 + * backwards. It is not possible to skip backwards past the beginning of
1.118 + * the string.
1.119 + *
1.120 + * <p>If the entire string has been read or skipped, then this method has
1.121 + * no effect and always returns 0.
1.122 + *
1.123 + * @exception IOException If an I/O error occurs
1.124 + */
1.125 + public long skip(long ns) throws IOException {
1.126 + synchronized (lock) {
1.127 + ensureOpen();
1.128 + if (next >= length)
1.129 + return 0;
1.130 + // Bound skip by beginning and end of the source
1.131 + long n = Math.min(length - next, ns);
1.132 + n = Math.max(-next, n);
1.133 + next += n;
1.134 + return n;
1.135 + }
1.136 + }
1.137 +
1.138 + /**
1.139 + * Tells whether this stream is ready to be read.
1.140 + *
1.141 + * @return True if the next read() is guaranteed not to block for input
1.142 + *
1.143 + * @exception IOException If the stream is closed
1.144 + */
1.145 + public boolean ready() throws IOException {
1.146 + synchronized (lock) {
1.147 + ensureOpen();
1.148 + return true;
1.149 + }
1.150 + }
1.151 +
1.152 + /**
1.153 + * Tells whether this stream supports the mark() operation, which it does.
1.154 + */
1.155 + public boolean markSupported() {
1.156 + return true;
1.157 + }
1.158 +
1.159 + /**
1.160 + * Marks the present position in the stream. Subsequent calls to reset()
1.161 + * will reposition the stream to this point.
1.162 + *
1.163 + * @param readAheadLimit Limit on the number of characters that may be
1.164 + * read while still preserving the mark. Because
1.165 + * the stream's input comes from a string, there
1.166 + * is no actual limit, so this argument must not
1.167 + * be negative, but is otherwise ignored.
1.168 + *
1.169 + * @exception IllegalArgumentException If readAheadLimit is < 0
1.170 + * @exception IOException If an I/O error occurs
1.171 + */
1.172 + public void mark(int readAheadLimit) throws IOException {
1.173 + if (readAheadLimit < 0){
1.174 + throw new IllegalArgumentException("Read-ahead limit < 0");
1.175 + }
1.176 + synchronized (lock) {
1.177 + ensureOpen();
1.178 + mark = next;
1.179 + }
1.180 + }
1.181 +
1.182 + /**
1.183 + * Resets the stream to the most recent mark, or to the beginning of the
1.184 + * string if it has never been marked.
1.185 + *
1.186 + * @exception IOException If an I/O error occurs
1.187 + */
1.188 + public void reset() throws IOException {
1.189 + synchronized (lock) {
1.190 + ensureOpen();
1.191 + next = mark;
1.192 + }
1.193 + }
1.194 +
1.195 + /**
1.196 + * Closes the stream and releases any system resources associated with
1.197 + * it. Once the stream has been closed, further read(),
1.198 + * ready(), mark(), or reset() invocations will throw an IOException.
1.199 + * Closing a previously closed stream has no effect.
1.200 + */
1.201 + public void close() {
1.202 + str = null;
1.203 + }
1.204 +}