/*

 * Copyright (c) 2001, 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 4401798

   @summary Check that single-character reads work properly

 */

import java.io.*;

public class One {

        InputStreamReader isr;

        StringBuffer sb;

        String expect;

        Test(byte[] in, String expect) throws Exception {

            isr = new InputStreamReader(new ByteArrayInputStream(in), "UTF-8");

            sb = new StringBuffer(expect.length());

            this.expect = expect;

            go();

        }

        void go() throws Exception {

            read();

            if (!expect.equals(sb.toString()))

                throw new Exception("Expected " + expect

                                    + ", got " + sb.toString());

        }

        abstract void read() throws IOException;

    }

    private static void test(String expect) throws Exception {

        byte[] in = expect.getBytes("UTF-8");

        new Test(in, expect) {

                public void read() throws IOException {

                    for (;;) {

                        int c;

                        if ((c = isr.read()) == -1)

                            break;

                        sb.append((char)c);

                    }

                }};

        new Test(in, expect) {

                public void read() throws IOException {

                    for (;;) {

                        char[] cb = new char[1];

                        if (isr.read(cb) == -1)

                            break;

                        sb.append(cb[0]);

                    }

                }};

        new Test(in, expect) {

                public void read() throws IOException {

                    for (;;) {

                        char[] cb = new char[2];

                        int n;

                        if ((n = isr.read(cb)) == -1)

                            break;

                        sb.append(cb[0]);

                        if (n == 2)

                            sb.append(cb[1]);

                    }

                }};

    }

    public static void main(String[] args) throws Exception {

        test("x");

        test("xy");

        test("xyz");

        test("\ud800\udc00");

        test("x\ud800\udc00");

    }

}