| /* |
| * Copyright (c) 1999, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code 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 code 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 in the LICENSE file that |
| * accompanied this code). |
| * |
| * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* @test |
| @bug 4150737 |
| @summary Ensure that StreamTokenizer does not read any further ahead |
| than is absolutely necessary |
| */ |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| import java.io.Reader; |
| import java.io.StreamTokenizer; |
| import java.io.IOException; |
| |
| |
| public class ReadAhead { |
| |
| |
| /* An InputStream subclass that cannot read past a given limit */ |
| static private class LimitedInputStream extends InputStream { |
| |
| private String input; |
| private int limit; /* Do not allow input[limit] to be read */ |
| private int next = 0; |
| |
| public LimitedInputStream(String input, int limit) { |
| this.input = input; |
| this.limit = limit; |
| } |
| |
| public int read() throws IOException { |
| if (next >= limit) |
| throw new IOException("Attempted to read too far in stream"); |
| return input.charAt(next++); |
| } |
| |
| } |
| |
| |
| /* A Reader subclass that cannot read past a given limit */ |
| static private class LimitedReader extends Reader { |
| |
| private String input; |
| private int limit; /* Do not allow input[limit] to be read */ |
| private int next = 0; |
| |
| public LimitedReader(String input, int limit) { |
| this.input = input; |
| this.limit = limit; |
| } |
| |
| public int read() throws IOException { |
| if (next >= limit) |
| throw new IOException("Attempted to read too far in stream"); |
| return input.charAt(next++); |
| } |
| |
| public int read(char[] b, int off, int len) throws IOException { |
| int top = off + len; |
| int i; |
| for (i = off; i < top; i++) { |
| int c = read(); |
| if (c < 0) break; |
| b[i] = (char)c; |
| } |
| return i - off; |
| } |
| |
| public void close() { } |
| |
| } |
| |
| |
| /* Interface for objects that can create new StreamTokenizers |
| with a given limited input */ |
| static private interface StreamTokenizerMaker { |
| public StreamTokenizer create(String input, int limit); |
| } |
| |
| static private void fail(String why) throws Exception { |
| throw new Exception(why); |
| } |
| |
| private static void test(StreamTokenizer st) throws Exception { |
| st.eolIsSignificant(true); |
| int tt = st.nextToken(); |
| if (tt != StreamTokenizer.TT_WORD) fail("expected TT_WORD"); |
| if (!st.sval.equals("foo")) fail("expected word token \"foo\""); |
| tt = st.nextToken(); |
| if (tt != StreamTokenizer.TT_EOL) fail("expected TT_EOL"); |
| } |
| |
| private static void test(StreamTokenizerMaker stm) throws Exception { |
| test(stm.create("foo\nx", 4)); |
| test(stm.create("foo\r\nx", 4)); |
| } |
| |
| |
| public static void main(String[] args) throws Exception { |
| |
| /* InputStream case */ |
| test(new StreamTokenizerMaker() { |
| public StreamTokenizer create(String input, int limit) { |
| return new StreamTokenizer(new LimitedInputStream(input, limit)); |
| }}); |
| |
| /* Reader case */ |
| test(new StreamTokenizerMaker() { |
| public StreamTokenizer create(String input, int limit) { |
| return new StreamTokenizer(new LimitedReader(input, limit)); |
| }}); |
| |
| } |
| |
| } |