JDK 11 jdk.jartool.jmod is the JMOD file for JDK 11 JAR tool, which can be invoked by the "jar" command.

JDK 11 JAR tool compiled class files are stored in \fyicenter\jdk-11.0.1\jmods\jdk.jartool.jmod.

JDK 11 JAR tool compiled class files are also linked and stored in the \fyicenter\jdk-11.0.1\lib\modules JImage file.

JDK 11 JAR tool source code files are stored in \fyicenter\jdk-11.0.1\lib\src.zip\jdk.jartool.

You can click and view the content of each source code file in the list below.

⏎ sun/tools/jar/CommandLine.java

/*
 * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package sun.tools.jar;

import java.io.IOException;
import java.io.Reader;
import java.io.FileReader;
import java.io.BufferedReader;
import java.io.StreamTokenizer;
import java.util.List;
import java.util.ArrayList;

/**
 * Various utility methods for processing Java tool command line arguments.
 *
 *  <p><b>This is NOT part of any API supported by Oracle.  If
 *  you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 */
public class CommandLine {
    /**
     * Process Win32-style command files for the specified command line
     * arguments and return the resulting arguments. A command file argument
     * is of the form '@file' where 'file' is the name of the file whose
     * contents are to be parsed for additional arguments. The contents of
     * the command file are parsed using StreamTokenizer and the original
     * '@file' argument replaced with the resulting tokens. Recursive command
     * files are not supported. The '@' character itself can be quoted with
     * the sequence '@@'.
     */
    public static String[] parse(String[] args)
        throws IOException
    {
        List<String> newArgs = new ArrayList<>(args.length);
        for (int i = 0; i < args.length; i++) {
            String arg = args[i];
            if (arg.length() > 1 && arg.charAt(0) == '@') {
                arg = arg.substring(1);
                if (arg.charAt(0) == '@') {
                    newArgs.add(arg);
                } else {
                    loadCmdFile(arg, newArgs);
                }
            } else {
                newArgs.add(arg);
            }
        }
        return newArgs.toArray(new String[newArgs.size()]);
    }

    private static void loadCmdFile(String name, List<String> args)
        throws IOException
    {
        Reader r = new BufferedReader(new FileReader(name));
        StreamTokenizer st = new StreamTokenizer(r);
        st.resetSyntax();
        st.wordChars(' ', 255);
        st.whitespaceChars(0, ' ');
        st.commentChar('#');
        st.quoteChar('"');
        st.quoteChar('\'');
        while (st.nextToken() != StreamTokenizer.TT_EOF) {
            args.add(st.sval);
        }
        r.close();
    }
}

⏎ sun/tools/jar/CommandLine.java

Or download all of them as a single archive file:

File name: jdk.jartool-11.0.1-src.zip
File size: 101994 bytes
Release date: 2018-11-04
Download 

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