Java example source code file (BadValue.java)

This example Java source code file (BadValue.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

badvalue, bytearrayinputstream, dervalue, eofexception, exception, first, fourth, ioexception, override, second, superslowstream, third

The BadValue.java Java example source code

/*
 * Copyright (c) 2009, 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 6864911
 * @summary ASN.1/DER input stream parser needs more work
 */

import java.io.*;
import sun.security.util.*;
import sun.misc.IOUtils;

public class BadValue {

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

        // Test IOUtils.readFully

        // We have 4 bytes
        InputStream in = new ByteArrayInputStream(new byte[10]);
        byte[] bs = IOUtils.readFully(in, 4, true);
        if (bs.length != 4 || in.available() != 6) {
            throw new Exception("First read error");
        }
        // But only 6 left
        bs = IOUtils.readFully(in, 10, false);
        if (bs.length != 6 || in.available() != 0) {
            throw new Exception("Second read error");
        }
        // MAX read as much as it can
        in = new ByteArrayInputStream(new byte[10]);
        bs = IOUtils.readFully(in, Integer.MAX_VALUE, true);
        if (bs.length != 10 || in.available() != 0) {
            throw new Exception("Second read error");
        }
        // MAX ignore readAll
        in = new ByteArrayInputStream(new byte[10]);
        bs = IOUtils.readFully(in, Integer.MAX_VALUE, false);
        if (bs.length != 10 || in.available() != 0) {
            throw new Exception("Second read error");
        }
        // 20>10, readAll means failure
        in = new ByteArrayInputStream(new byte[10]);
        try {
            bs = IOUtils.readFully(in, 20, true);
            throw new Exception("Third read error");
        } catch (EOFException e) {
            // OK
        }
        int bignum = 10 * 1024 * 1024;
        bs = IOUtils.readFully(new SuperSlowStream(bignum), -1, true);
        if (bs.length != bignum) {
            throw new Exception("Fourth read error");
        }

        // Test DerValue
        byte[] input = {0x04, (byte)0x84, 0x40, 0x00, 0x42, 0x46, 0x4b};
        try {
            new DerValue(new ByteArrayInputStream(input));
        } catch (IOException ioe) {
            // This is OK
        }
    }
}

/**
 * An InputStream contains a given number of bytes, but only returns one byte
 * per read.
 */
class SuperSlowStream extends InputStream {
    private int p;
    /**
     * @param Initial capacity
     */
    public SuperSlowStream(int capacity) {
        p = capacity;
    }
    @Override
    public int read() throws IOException {
        if (p > 0) {
            p--;
            return 0;
        } else {
            return -1;
        }
    }
    @Override
    public int read(byte b[], int off, int len) throws IOException {
        if (len == 0) return 0;
        if (p > 0) {
            p--;
            b[off] = 0;
            return 1;
        } else {
            return -1;
        }
    }
}