com.davidjohnburrowes.format.encode.Bin2Hex Maven / Gradle / Ivy

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A java library to take apart and assemble jpeg files
There is a newer version: 1.0.1

/*
 *  Copyright 2014,2017 柏大衛
 *
 * 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.
 */

package com.davidjohnburrowes.format.encode;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;

/**
 * Given an input stream of binary data, write out a textual version of the same
 * data in a hexadecimal format.  Thus, an input of "ABC" might be written out
 * as 40 41 42.
 *
 * Instances of this class have a variety of configuration properties that control
 * how the output is formatted, exactly.
 */
public class Bin2Hex {
	/**
	 * The number of bytes to write out per line (byte is two hex characters)
	 */
	private int bytesPerLine;

	/**
	 *
	 */
	public Bin2Hex() {
		this.bytesPerLine = 0;
	}

	/**
	 * Sets the number of bytes to write out on each line.
	 * A value of 0 means no limit.
	 * @param bytesPerLine The number of bytes to write out on each line
	 */
	public void setBytesPerLine(int bytesPerLine) {
		if (bytesPerLine < 0) {
			throw new IllegalArgumentException("bytes per line must be positive");
		}
		this.bytesPerLine = bytesPerLine;
	}

	/**
	 * @return The number of bytes per line.
	 */
	public int getBytesPerLine() {
		return bytesPerLine;
	}

	/**
	 * Using any configuration properties set on the instance, convert the contents of
	 * the input stream to the output stream.
	 *
	 * @param input The stream to read bytes from (not null)
	 * @param outputStream The stream to write the textual representation to (not null)
	 * @throws IOException If something goes wonky on io.
	 * @throws IllegalArgumentException If either argument is null
	 */
	public void convert(InputStream input, OutputStream outputStream) throws IOException {
		if (input == null) {
			throw new IllegalArgumentException("Input may not be null");
		}

		if (outputStream == null) {
			throw new IllegalArgumentException("Output may not be null");
		}

		PrintWriter output = new PrintWriter(outputStream);
		int aByte = input.read();
		int count = 0;

		while (aByte != -1) {
			if ((count >= bytesPerLine) && (bytesPerLine != 0)) {
				output.printf("\n");
				count = 0;
			} else if (count > 0) {
				output.printf(" ");
			}
			output.printf("%02x", aByte);

			count++;

			aByte = input.read();
		}
		output.flush();
	}
}