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Wrappers for PrintStream with copy, redirect, filter and passthrough implementations.
There is a newer version: 0.4.0
/**
 * The MIT License (MIT)
 *
 * Copyright (c) 2017 Paul Campbell
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
 * and associated documentation files (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies
 * or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package net.kemitix.wrapper.printstream;

import lombok.NonNull;
import lombok.val;
import net.kemitix.wrapper.Wrapper;
import net.kemitix.wrapper.WrapperState;

import java.io.PrintStream;
import java.util.Objects;
import java.util.function.Consumer;

/**
 * Basic wrapper for {@link PrintStream} that simply passes all writes to the intercepted PrintStream, or to another
 * wrapper.
 *
 * @author Paul Campbell ([email protected])
 */
public class PassthroughPrintStreamWrapper extends PrintStream implements Wrapper {

    private final WrapperState wrapperState;

    /**
     * Constructor to wrap a PrintStream.
     *
     * @param original the PrintStream to intercept
     */
    public PassthroughPrintStreamWrapper(final PrintStream original) {
        super(original);
        this.wrapperState = new WrapperState<>(original);
    }

    /**
     * Constructor to wrap an existing {@code Wrapper}.
     *
     * @param object the wrapper to wrap
     */
    public PassthroughPrintStreamWrapper(final Wrapper object) {
        super(Objects.requireNonNull(object, "wrapper")
                     .getWrapperCore());
        this.wrapperState = new WrapperState<>(object);
    }

    /**
     * Writes the specified byte to this stream.
     *
     * If the byte is a newline and automatic flushing is enabled then the flush method will be invoked.
     *
     * Note that the byte is written as given; to write a character that will be translated according to the
     * platform's default character encoding, use the print(char) or println(char) methods.
     *
     * This implementation passes the byte, unmodified, to the intercepted {@link PrintStream} or {@code
     * Wrapper}.
     *
     * @param b The byte to be written
     *
     * @see #print(char)
     * @see #println(char)
     */
    @Override
    public void write(final int b) {
        val delegate = getWrapperDelegate();
        delegate.write(b);
    }

    /**
     * Writes len bytes from the specified byte array starting at offset off to this stream.
     *
     * If automatic flushing is enabled then the flush method will be invoked.
     *
     * Note that the bytes will be written as given; to write characters that will be translated according to the
     * platform's default character encoding, use the print(char) or println(char) methods.
     *
     * This implementation passes the bytes, unmodified, to the intercepted {@link PrintStream} or {@code
     * Wrapper}.
     *
     * @param buf A byte array
     * @param off Offset from which to start taking bytes
     * @param len Number of bytes to write
     */
    @Override
    public void write(@NonNull final byte[] buf, final int off, final int len) {
        val delegate = getWrapperDelegate();
        delegate.write(buf, off, len);
    }

    @Override
    public final WrapperState getWrapperState() {
        return wrapperState;
    }

    /**
     * Scan the buffer, from off to len, and give it to the byteConsumer.
     *
     * @param buf          the buffer to process
     * @param off          the offset within the buffer to begin
     * @param len          the number of bytes to process
     * @param byteConsumer the consumer to process each byte
     */
    protected final void forEachByteInBuffer(
            final byte[] buf, final int off, final int len, final Consumer byteConsumer
                                            ) {
        if (len < 0) {
            throw new IndexOutOfBoundsException(
                    String.format("buf.length: %d, off: %d, len: %d", buf.length, off, len));
        }
        for (int i = 0; i < len; i++) {
            byteConsumer.accept(buf[off + i]);
        }
    }
}