at.ac.univie.isc.asio.io.Payload.java Source code

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Here is the source code for at.ac.univie.isc.asio.io.Payload.java

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/*
 * #%L
 * asio test
 * %%
 * Copyright (C) 2013 - 2015 Research Group Scientific Computing, University of Vienna
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
package at.ac.univie.isc.asio.io;

import at.ac.univie.isc.asio.Unchecked;
import com.google.common.io.ByteSource;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Random;

/**
 * Aid in generating and using binary data.
 */
public final class Payload {
    private static final Random RNG = new Random();

    private Payload() {
        /* no instances */ }

    /**
     * Generate a fixed size {@code byte[]} with random contents.
     *
     * @param size of generated array
     * @return randomly filled byte array
     */
    public static byte[] randomWithLength(final int size) {
        assert size >= 0 : "payload cannot have negative size";
        final byte[] payload = new byte[size];
        RNG.nextBytes(payload);
        return payload;
    }

    private static final char[] ALPHA_NUM = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890".toCharArray();

    /**
     * Generate a fixed size {@code String} with random, alpha-numeric content.
     *
     * @param length length of generated text
     * @return random, alpha-numeric string
     */
    public static String randomText(final int length) {
        assert length >= 0 : "payload cannot have negative size";
        final char[] content = new char[length];
        for (int i = 0; i < content.length; i++) {
            content[i] = ALPHA_NUM[RNG.nextInt(ALPHA_NUM.length)];
        }
        return String.copyValueOf(content);
    }

    /**
     * Convert raw utf-8 encoded data back to {@code String}. It is not checked whether the data is actually
     * utf-8 encoded.
     *
     * @param data raw binary data of an utf-8 encoded string
     * @return decoded data as String
     */
    public static String decodeUtf8(final byte[] data) {
        return new String(data, StandardCharsets.UTF_8);
    }

    /**
     * Convert a {@code String} to utf-8 encoded data.
     *
     * @param text to be converted
     * @return utf-8 encoded binary data
     */
    public static byte[] encodeUtf8(final String text) {
        return text.getBytes(StandardCharsets.UTF_8);
    }

    /**
     * Copy the content from given {@code ByteSource} to an array.
     *
     * @param source source of binary data
     * @return byte array containing the contents of the {@code source}
     * @throw UncheckedIOException if reading the source fails
     */
    public static byte[] asArray(final ByteSource source) {
        try {
            return source.read();
        } catch (IOException e) {
            throw new Unchecked.UncheckedIOException(e);
        }
    }
}