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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * 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).
 *
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IOUtils: A collection of IO-related public static methods.

/**
 * IOUtils: A collection of IO-related public static methods.
 */

package sun.security.util;

import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;

public class IOUtils {

    
Read exactly length of bytes from in. 
 Note that this method is safe to be called with unknown large length argument. The memory used is proportional to the actual bytes available. An exception is thrown if there are not enough bytes in the stream. 
Params:
  • is – input stream, must not be null
  • length – number of bytes to read
Throws:
Returns:bytes read
/**
     * Read exactly {@code length} of bytes from {@code in}.
     *
     * <p> Note that this method is safe to be called with unknown large
     * {@code length} argument. The memory used is proportional to the
     * actual bytes available. An exception is thrown if there are not
     * enough bytes in the stream.
     *
     * @param is input stream, must not be null
     * @param length number of bytes to read
     * @return bytes read
     * @throws EOFException if there are not enough bytes in the stream
     * @throws IOException if an I/O error occurs or {@code length} is negative
     * @throws OutOfMemoryError if an array of the required size cannot be
     *         allocated.
     */
    public static byte[] readExactlyNBytes(InputStream is, int length)
            throws IOException {
        if (length < 0) {
            throw new IOException("length cannot be negative: " + length);
        }
        byte[] data = is.readNBytes(length);
        if (data.length < length) {
            throw new EOFException();
        }
        return data;
    }
}