commons-net.jar is the bytecode of Apache Commons Net library, which implements the client side of many basic Internet protocols.

Apache Commons Net Source Code files are provided in the binary packge (commons-net-3.8.0-bin.zip). You can download it at Apache Commons Net Website.

The source code of commons-net-3.8.0.jar is provided below:

⏎ org/apache/commons/net/nntp/SimpleNNTPHeader.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.commons.net.nntp;

/**
 * This class is used to construct the bare minimum
 * acceptable header for most news readers.  To construct more
 * complicated headers you should refer to RFC 822.  When the
 * Java Mail API is finalized, you will be
 * able to use it to compose fully compliant Internet text messages.
 * <p>
 * The main purpose of the class is to faciliatate the article posting
 * process, by relieving the programmer from having to explicitly format
 * an article header.  For example:
 * <pre>
 * writer = client.postArticle();
 * if(writer == null) // failure
 *   return false;
 * header = new SimpleNNTPHeader("foobar@foo.com", "Just testing");
 * header.addNewsgroup("alt.test");
 * header.addHeaderField("Organization", "Foobar, Inc.");
 * writer.write(header.toString());
 * writer.write("This is just a test");
 * writer.close();
 * if(!client.completePendingCommand()) // failure
 *   return false;
 * </pre>
 *
 * @see NNTPClient
 */

public class SimpleNNTPHeader
{
    private final String subject, from;
    private final StringBuilder newsgroups;
    private final StringBuilder headerFields;
    private int newsgroupCount;

    /**
     * Creates a new SimpleNNTPHeader instance initialized with the given
     * from and subject header field values.
     * <p>
     * @param from  The value of the <code>From:</code> header field.  This
     *              should be the article poster's email address.
     * @param subject  The value of the <code>Subject:</code> header field.
     *              This should be the subject of the article.
     */
    public SimpleNNTPHeader(final String from, final String subject)
    {
        this.from = from;
        this.subject = subject;
        this.newsgroups = new StringBuilder();
        this.headerFields = new StringBuilder();
        this.newsgroupCount = 0;
    }

    /**
     * Adds a newsgroup to the article <code>Newsgroups:</code> field.
     * <p>
     * @param newsgroup  The newsgroup to add to the article's newsgroup
     *                   distribution list.
     */
    public void addNewsgroup(final String newsgroup)
    {
        if (newsgroupCount++ > 0) {
            newsgroups.append(',');
        }
        newsgroups.append(newsgroup);
    }

    /**
     * Adds an arbitrary header field with the given value to the article
     * header.  These headers will be written after the From, Newsgroups,
     * and Subject fields when the SimpleNNTPHeader is convertered to a string.
     * An example use would be:
     * <pre>
     * header.addHeaderField("Organization", "Foobar, Inc.");
     * </pre>
     * <p>
     * @param headerField  The header field to add, not including the colon.
     * @param value  The value of the added header field.
     */
    public void addHeaderField(final String headerField, final String value)
    {
        headerFields.append(headerField);
        headerFields.append(": ");
        headerFields.append(value);
        headerFields.append('\n');
    }


    /**
     * Returns the address used in the <code> From: </code> header field.
     * <p>
     * @return The from address.
     */
    public String getFromAddress()
    {
        return from;
    }

    /**
     * Returns the subject used in the <code> Subject: </code> header field.
     * <p>
     * @return The subject.
     */
    public String getSubject()
    {
        return subject;
    }

    /**
     * Returns the contents of the <code> Newsgroups: </code> header field.
     * <p>
     * @return The comma-separated list of newsgroups to which the article
     *         is being posted.
     */
    public String getNewsgroups()
    {
        return newsgroups.toString();
    }

    /**
     * Converts the SimpleNNTPHeader to a properly formatted header in
     * the form of a String, including the blank line used to separate
     * the header from the article body.
     * <p>
     * @return The article header in the form of a String.
     */
    @Override
    public String toString()
    {
        final StringBuilder header = new StringBuilder();

        header.append("From: ");
        header.append(from);
        header.append("\nNewsgroups: ");
        header.append(newsgroups.toString());
        header.append("\nSubject: ");
        header.append(subject);
        header.append('\n');
        if (headerFields.length() > 0) {
            header.append(headerFields.toString());
        }
        header.append('\n');

        return header.toString();
    }
}

⏎ org/apache/commons/net/nntp/SimpleNNTPHeader.java

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File name: commons-net-3.8.0-sources.jar
File size: 437325 bytes
Release date: 2020-01-22
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