test/java/io/DataInputStream/ReadLinePushback.java

/*
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 * 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.
 *
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 */

/* @test
   @bug 4093646
   @summary Make sure readLine would not push back -1.
   */

import java.io.*;

public class ReadLinePushback {

    public static void main(String args[]) throws Exception {
        PushbackInputStream pis = new PushbackInputStream
            ((new StringBufferInputStream("\r")));
        DataInputStream dis = new DataInputStream(pis);

        String line = dis.readLine();
        if (line == null) {
            throw new Exception ("Got null, should return empty line");
        }

        int count = pis.available();

        if (count != 0) {
            throw new Exception ("Test failed: available() returns "
                                 + count + "when the file is empty");
        }
    }
}