Apache Log4j IOStreams is a Log4j API extension that provides numerous classes from java.io that can either write to a Logger while writing to another OutputStream or Writer, or the contents read by an InputStream or Reader can be wiretapped by a Logger.

Bytecode (Java 8) for Apache Log4j IOStreams is provided in a separate JAR file like log4j-iostreams-2.14.1.jar.

Source Code files for Apache Log4j IOStreams are provided in both binary packge like apache-log4j-2.14.1-bin.zip and source package like apache-log4j-2.14.1-src.zip. You can download them at Apache Log4j Website.

You can also browse Source Code files for Apache Log4j IOStreams 2.14.1 below.

⏎ org/apache/logging/log4j/io/internal/InternalFilterOutputStream.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.logging.log4j.io.internal;

import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.Charset;

import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.Marker;
import org.apache.logging.log4j.io.ByteStreamLogger;
import org.apache.logging.log4j.spi.ExtendedLogger;

/**
 * Internal class that exists primarly to allow location calculations to work.
 *
 * @since 2.12
 */
public class InternalFilterOutputStream extends FilterOutputStream {

    private final ByteStreamLogger logger;
    private final String fqcn;

    public InternalFilterOutputStream(final OutputStream out, final Charset charset, final ExtendedLogger logger,
                                       final String fqcn, final Level level, final Marker marker) {
        super(out);
        this.logger = new ByteStreamLogger(logger, level, marker, charset);
        this.fqcn = fqcn;
    }

    @Override
    public void close() throws IOException {
        this.out.close();
        this.logger.close(this.fqcn);
    }

    @Override
    public void flush() throws IOException {
        this.out.flush();
    }

    @Override
    public String toString() {
        return "{stream=" + this.out + '}';
    }

    @Override
    public void write(final byte[] b) throws IOException {
        this.out.write(b);
        this.logger.put(this.fqcn, b, 0, b.length);
    }

    @Override
    public void write(final byte[] b, final int off, final int len) throws IOException {
        this.out.write(b, off, len);
        this.logger.put(this.fqcn, b, off, len);
    }

    @Override
    public void write(final int b) throws IOException {
        this.out.write(b);
        this.logger.put(this.fqcn, (byte) (b & 0xFF));
    }
}

⏎ org/apache/logging/log4j/io/internal/InternalFilterOutputStream.java

Or download all of them as a single archive file:

File name: log4j-iostreams-2.14.1-sources.jar
File size: 43404 bytes
Release date: 2021-03-06
Download 

⇒ Source Code for Apache Log4j Web Servlet Containers

⇐ Source Code for Apache Log4j to SLF4J Adapter

⇑ Downloading and Reviewing Apache Log4j Packages

⇑⇑ FAQ for Apache Log4j