java/11 : java.management/javax/management/remote/JMXServiceURL.java

JMXServiceURL
https://openjdk.java.net/
GPLv2 + Classpath Exception
/*
 * Copyright (c) 2002, 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
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 *
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package javax.management.remote;


import com.sun.jmx.remote.util.ClassLogger;
import com.sun.jmx.remote.util.EnvHelp;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;

import java.io.Serializable;
import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.MalformedURLException;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.BitSet;
import java.util.Enumeration;
import java.util.Locale;
import java.util.StringTokenizer;

The address of a JMX API connector server.  Instances of this class
are immutable.
The address is an Abstract Service URL for SLP, as
defined in RFC 2609 and amended by RFC 3111.  It must look like
this:

service:jmx:protocol:sap

Here, protocol is the transport
protocol to be used to connect to the connector server.  It is
a string of one or more ASCII characters, each of which is a
letter, a digit, or one of the characters + or
-.  The first character must be a letter.
Uppercase letters are converted into lowercase ones.
sap is the address at which the connector
server is found.  This address uses a subset of the syntax defined
by RFC 2609 for IP-based protocols.  It is a subset because the
user@host syntax is not supported.
The other syntaxes defined by RFC 2609 are not currently
supported by this class.
The supported syntax is:

//[host[:port]][url-path]

Square brackets [] indicate optional parts of
the address.  Not all protocols will recognize all optional
parts.
The host is a host name, an IPv4 numeric
host address, or an IPv6 numeric address enclosed in square
brackets.
The port is a decimal port number.  0
means a default or anonymous port, depending on the protocol.
The host and port
can be omitted.  The port cannot be supplied
without a host.
The url-path, if any, begins with a slash
(/) or a semicolon (;) and continues to
the end of the address.  It can contain attributes using the
semicolon syntax specified in RFC 2609.  Those attributes are not
parsed by this class and incorrect attribute syntax is not
detected.
Although it is legal according to RFC 2609 to have a
url-path that begins with a semicolon, not
all implementations of SLP allow it, so it is recommended to avoid
that syntax.
Case is not significant in the initial
service:jmx:protocol string or in the host
part of the address.  Depending on the protocol, case can be
significant in the url-path.
See Also: RFC 2609,
 * "Service Templates and Service: Schemes"
RFC 3111,
 * "Service Location Protocol Modifications for IPv6"
Since: 1.5/**
 * <p>The address of a JMX API connector server.  Instances of this class
 * are immutable.</p>
 *
 * <p>The address is an <em>Abstract Service URL</em> for SLP, as
 * defined in RFC 2609 and amended by RFC 3111.  It must look like
 * this:</p>
 *
 * <blockquote>
 *
 * <code>service:jmx:<em>protocol</em>:<em>sap</em></code>
 *
 * </blockquote>
 *
 * <p>Here, <code><em>protocol</em></code> is the transport
 * protocol to be used to connect to the connector server.  It is
 * a string of one or more ASCII characters, each of which is a
 * letter, a digit, or one of the characters <code>+</code> or
 * <code>-</code>.  The first character must be a letter.
 * Uppercase letters are converted into lowercase ones.</p>
 *
 * <p><code><em>sap</em></code> is the address at which the connector
 * server is found.  This address uses a subset of the syntax defined
 * by RFC 2609 for IP-based protocols.  It is a subset because the
 * <code>user@host</code> syntax is not supported.</p>
 *
 * <p>The other syntaxes defined by RFC 2609 are not currently
 * supported by this class.</p>
 *
 * <p>The supported syntax is:</p>
 *
 * <blockquote>
 *
 * <code>//<em>[host[</em>:<em>port]][url-path]</em></code>
 *
 * </blockquote>
 *
 * <p>Square brackets <code>[]</code> indicate optional parts of
 * the address.  Not all protocols will recognize all optional
 * parts.</p>
 *
 * <p>The <code><em>host</em></code> is a host name, an IPv4 numeric
 * host address, or an IPv6 numeric address enclosed in square
 * brackets.</p>
 *
 * <p>The <code><em>port</em></code> is a decimal port number.  0
 * means a default or anonymous port, depending on the protocol.</p>
 *
 * <p>The <code><em>host</em></code> and <code><em>port</em></code>
 * can be omitted.  The <code><em>port</em></code> cannot be supplied
 * without a <code><em>host</em></code>.</p>
 *
 * <p>The <code><em>url-path</em></code>, if any, begins with a slash
 * (<code>/</code>) or a semicolon (<code>;</code>) and continues to
 * the end of the address.  It can contain attributes using the
 * semicolon syntax specified in RFC 2609.  Those attributes are not
 * parsed by this class and incorrect attribute syntax is not
 * detected.</p>
 *
 * <p>Although it is legal according to RFC 2609 to have a
 * <code><em>url-path</em></code> that begins with a semicolon, not
 * all implementations of SLP allow it, so it is recommended to avoid
 * that syntax.</p>
 *
 * <p>Case is not significant in the initial
 * <code>service:jmx:<em>protocol</em></code> string or in the host
 * part of the address.  Depending on the protocol, case can be
 * significant in the <code><em>url-path</em></code>.</p>
 *
 * @see <a
 * href="http://www.ietf.org/rfc/rfc2609.txt">RFC 2609,
 * "Service Templates and <code>Service:</code> Schemes"</a>
 * @see <a
 * href="http://www.ietf.org/rfc/rfc3111.txt">RFC 3111,
 * "Service Location Protocol Modifications for IPv6"</a>
 *
 * @since 1.5
 */
public class JMXServiceURL implements Serializable {

    private static final long serialVersionUID = 8173364409860779292L;

    Constructs a JMXServiceURL by parsing a Service URL
string.
Params: serviceURL – the URL string to be parsed.
Throws: NullPointerException – if serviceURL is
null.
MalformedURLException – if serviceURL
does not conform to the syntax for an Abstract Service URL or
if it is not a valid name for a JMX Remote API service.  A
JMXServiceURL must begin with the string
"service:jmx:" (case-insensitive).  It must not
contain any characters that are not printable ASCII characters./**
     * <p>Constructs a <code>JMXServiceURL</code> by parsing a Service URL
     * string.</p>
     *
     * @param serviceURL the URL string to be parsed.
     *
     * @exception NullPointerException if <code>serviceURL</code> is
     * null.
     *
     * @exception MalformedURLException if <code>serviceURL</code>
     * does not conform to the syntax for an Abstract Service URL or
     * if it is not a valid name for a JMX Remote API service.  A
     * <code>JMXServiceURL</code> must begin with the string
     * <code>"service:jmx:"</code> (case-insensitive).  It must not
     * contain any characters that are not printable ASCII characters.
     */
    public JMXServiceURL(String serviceURL) throws MalformedURLException {
        final int serviceURLLength = serviceURL.length();

        /* Check that there are no non-ASCII characters in the URL,
           following RFC 2609.  */
        for (int i = 0; i < serviceURLLength; i++) {
            char c = serviceURL.charAt(i);
            if (c < 32 || c >= 127) {
                throw new MalformedURLException("Service URL contains " +
                                                "non-ASCII character 0x" +
                                                Integer.toHexString(c));
            }
        }

        // Parse the required prefix
        final String requiredPrefix = "service:jmx:";
        final int requiredPrefixLength = requiredPrefix.length();
        if (!serviceURL.regionMatches(true, // ignore case
                                      0,    // serviceURL offset
                                      requiredPrefix,
                                      0,    // requiredPrefix offset
                                      requiredPrefixLength)) {
            throw new MalformedURLException("Service URL must start with " +
                                            requiredPrefix);
        }

        // Parse the protocol name
        final int protoStart = requiredPrefixLength;
        final int protoEnd = indexOf(serviceURL, ':', protoStart);
        this.protocol =
            serviceURL.substring(protoStart, protoEnd).toLowerCase(Locale.ENGLISH);

        if (!serviceURL.regionMatches(protoEnd, "://", 0, 3)) {
            throw new MalformedURLException("Missing \"://\" after " +
                                            "protocol name");
        }

        // Parse the host name
        final int hostStart = protoEnd + 3;
        final int hostEnd;
        if (hostStart < serviceURLLength
            && serviceURL.charAt(hostStart) == '[') {
            hostEnd = serviceURL.indexOf(']', hostStart) + 1;
            if (hostEnd == 0)
                throw new MalformedURLException("Bad host name: [ without ]");
            this.host = serviceURL.substring(hostStart + 1, hostEnd - 1);
            if (!isNumericIPv6Address(this.host)) {
                throw new MalformedURLException("Address inside [...] must " +
                                                "be numeric IPv6 address");
            }
        } else {
            hostEnd =
                indexOfFirstNotInSet(serviceURL, hostNameBitSet, hostStart);
            this.host = serviceURL.substring(hostStart, hostEnd);
        }

        // Parse the port number
        final int portEnd;
        if (hostEnd < serviceURLLength && serviceURL.charAt(hostEnd) == ':') {
            if (this.host.length() == 0) {
                throw new MalformedURLException("Cannot give port number " +
                                                "without host name");
            }
            final int portStart = hostEnd + 1;
            portEnd =
                indexOfFirstNotInSet(serviceURL, numericBitSet, portStart);
            final String portString = serviceURL.substring(portStart, portEnd);
            try {
                this.port = Integer.parseInt(portString);
            } catch (NumberFormatException e) {
                throw new MalformedURLException("Bad port number: \"" +
                                                portString + "\": " + e);
            }
        } else {
            portEnd = hostEnd;
            this.port = 0;
        }

        // Parse the URL path
        final int urlPathStart = portEnd;
        if (urlPathStart < serviceURLLength)
            this.urlPath = serviceURL.substring(urlPathStart);
        else
            this.urlPath = "";

        validate();
    }

    Constructs a JMXServiceURL with the given protocol, host, and port. This constructor is equivalent to 
JMXServiceURL(protocol, host, port, null).
Params: protocol – the protocol part of the URL.  If null, defaults
to jmxmp.
host – the host part of the URL. If host is null and if
local host name can be resolved to an IP, then host defaults
to local host name as determined by
InetAddress.getLocalHost().getHostName(). If host is null
and if local host name cannot be resolved to an IP, then host
defaults to numeric IP address of one of the active network interfaces.
If host is a numeric IPv6 address, it can optionally be enclosed in
square brackets [].
port – the port part of the URL.
Throws: MalformedURLException – if one of the parts is
syntactically incorrect, or if host is null and it
is not possible to find the local host name, or if
port is negative./**
     * <p>Constructs a <code>JMXServiceURL</code> with the given protocol,
     * host, and port.  This constructor is equivalent to
     * {@link #JMXServiceURL(String, String, int, String)
     * JMXServiceURL(protocol, host, port, null)}.</p>
     *
     * @param protocol the protocol part of the URL.  If null, defaults
     * to <code>jmxmp</code>.
     *
     * @param host the host part of the URL. If host is null and if
     * local host name can be resolved to an IP, then host defaults
     * to local host name as determined by
     * <code>InetAddress.getLocalHost().getHostName()</code>. If host is null
     * and if local host name cannot be resolved to an IP, then host
     * defaults to numeric IP address of one of the active network interfaces.
     * If host is a numeric IPv6 address, it can optionally be enclosed in
     * square brackets <code>[]</code>.
     *
     * @param port the port part of the URL.
     *
     * @exception MalformedURLException if one of the parts is
     * syntactically incorrect, or if <code>host</code> is null and it
     * is not possible to find the local host name, or if
     * <code>port</code> is negative.
     */
    public JMXServiceURL(String protocol, String host, int port)
            throws MalformedURLException {
        this(protocol, host, port, null);
    }

    Constructs a JMXServiceURL with the given parts.
Params: protocol – the protocol part of the URL.  If null, defaults
to jmxmp.
host – the host part of the URL. If host is null and if
local host name can be resolved to an IP, then host defaults
to local host name as determined by
InetAddress.getLocalHost().getHostName(). If host is null
and if local host name cannot be resolved to an IP, then host
defaults to numeric IP address of one of the active network interfaces.
If host is a numeric IPv6 address, it can optionally be enclosed in
square brackets [].
port – the port part of the URL.
urlPath – the URL path part of the URL.  If null, defaults to
the empty string.
Throws: MalformedURLException – if one of the parts is
syntactically incorrect, or if host is null and it
is not possible to find the local host name, or if
port is negative./**
     * <p>Constructs a <code>JMXServiceURL</code> with the given parts.
     *
     * @param protocol the protocol part of the URL.  If null, defaults
     * to <code>jmxmp</code>.
     *
     * @param host the host part of the URL. If host is null and if
     * local host name can be resolved to an IP, then host defaults
     * to local host name as determined by
     * <code>InetAddress.getLocalHost().getHostName()</code>. If host is null
     * and if local host name cannot be resolved to an IP, then host
     * defaults to numeric IP address of one of the active network interfaces.
     * If host is a numeric IPv6 address, it can optionally be enclosed in
     * square brackets <code>[]</code>.
     *
     * @param port the port part of the URL.
     *
     * @param urlPath the URL path part of the URL.  If null, defaults to
     * the empty string.
     *
     * @exception MalformedURLException if one of the parts is
     * syntactically incorrect, or if <code>host</code> is null and it
     * is not possible to find the local host name, or if
     * <code>port</code> is negative.
     */
    public JMXServiceURL(String protocol, String host, int port,
                         String urlPath)
            throws MalformedURLException {
        if (protocol == null)
            protocol = "jmxmp";

        if (host == null) {
            InetAddress local;
            try {
                local = InetAddress.getLocalHost();
                host = local.getHostName();

                /* We might have a hostname that violates DNS naming
                rules, for example that contains an `_'.  While we
                could be strict and throw an exception, this is rather
                user-hostile.  Instead we use its numerical IP address.
                We can only reasonably do this for the host==null case.
                If we're given an explicit host name that is illegal we
                have to reject it.  (Bug 5057532.)  */
                try {
                    validateHost(host, port);
                } catch (MalformedURLException e) {
                   if (logger.fineOn()) {
                    logger.fine("JMXServiceURL",
                                "Replacing illegal local host name " +
                                host + " with numeric IP address " +
                                "(see RFC 1034)", e);
                }
                host = local.getHostAddress();
                }
            } catch (UnknownHostException e) {
                try {
                    /*
                    If hostname cannot be resolved, we will try and use numeric
                    IPv4/IPv6 address. If host=null while starting agent,
                    we know that it will be started on all interfaces - 0.0.0.0.
                    Hence we will use IP address of first active non-loopback
                    interface
                    */
                    host = getActiveNetworkInterfaceIP();
                    if (host == null) {
                        throw new MalformedURLException("Unable"
                                + " to resolve hostname or "
                                + "get valid IP address");
                    }
                } catch (SocketException ex) {
                    throw new MalformedURLException("Unable"
                            + " to resolve hostname or get valid IP address");
                }
            }
        }

        if (host.startsWith("[")) {
            if (!host.endsWith("]")) {
                throw new MalformedURLException("Host starts with [ but " +
                                                "does not end with ]");
            }
            host = host.substring(1, host.length() - 1);
            if (!isNumericIPv6Address(host)) {
                throw new MalformedURLException("Address inside [...] must " +
                                                "be numeric IPv6 address");
            }
            if (host.startsWith("["))
                throw new MalformedURLException("More than one [[...]]");
        }

        this.protocol = protocol.toLowerCase(Locale.ENGLISH);
        this.host = host;
        this.port = port;

        if (urlPath == null)
            urlPath = "";
        this.urlPath = urlPath;

        validate();
    }

    private String getActiveNetworkInterfaceIP() throws SocketException {
        Enumeration<NetworkInterface>
                networkInterface = NetworkInterface.getNetworkInterfaces();
        String ipv6AddrStr = null;
        while (networkInterface.hasMoreElements()) {
            NetworkInterface nic = networkInterface.nextElement();
            if (nic.isUp() && !nic.isLoopback()) {
                Enumeration<InetAddress> inet = nic.getInetAddresses();
                while (inet.hasMoreElements()) {
                    InetAddress addr = inet.nextElement();
                    if (addr instanceof Inet4Address
                            && !addr.isLinkLocalAddress()) {
                        return addr.getHostAddress();
                    }else if (addr instanceof Inet6Address
                            && !addr.isLinkLocalAddress()) {
                        /*
                        We save last seen IPv6 address which we will return
                        if we do not find any interface with IPv4 address.
                        */
                        ipv6AddrStr = addr.getHostAddress();
                    }
                }
            }
        }
        return ipv6AddrStr;
    }

    private static final String INVALID_INSTANCE_MSG =
            "Trying to deserialize an invalid instance of JMXServiceURL";
    private void readObject(ObjectInputStream  inputStream) throws IOException, ClassNotFoundException {
        ObjectInputStream.GetField gf = inputStream.readFields();
        String h = (String)gf.get("host", null);
        int p = gf.get("port", -1);
        String proto = (String)gf.get("protocol", null);
        String url = (String)gf.get("urlPath", null);

        if (proto == null || url == null || h == null) {
            StringBuilder sb = new StringBuilder(INVALID_INSTANCE_MSG).append('[');
            boolean empty = true;
            if (proto == null) {
                sb.append("protocol=null");
                empty = false;
            }
            if (h == null) {
                sb.append(empty ? "" : ",").append("host=null");
                empty = false;
            }
            if (url == null) {
                sb.append(empty ? "" : ",").append("urlPath=null");
            }
            sb.append(']');
            throw new InvalidObjectException(sb.toString());
        }

        if (h.contains("[") || h.contains("]")) {
            throw new InvalidObjectException("Invalid host name: " + h);
        }

        try {
            validate(proto, h, p, url);
            this.protocol = proto;
            this.host = h;
            this.port = p;
            this.urlPath = url;
        } catch (MalformedURLException e) {
            throw new InvalidObjectException(INVALID_INSTANCE_MSG + ": " +
                                             e.getMessage());
        }

    }

    private void validate(String proto, String h, int p, String url)
        throws MalformedURLException {
        // Check protocol
        final int protoEnd = indexOfFirstNotInSet(proto, protocolBitSet, 0);
        if (protoEnd == 0 || protoEnd < proto.length()
            || !alphaBitSet.get(proto.charAt(0))) {
            throw new MalformedURLException("Missing or invalid protocol " +
                                            "name: \"" + proto + "\"");
        }

        // Check host
        validateHost(h, p);

        // Check port
        if (p < 0)
            throw new MalformedURLException("Bad port: " + p);

        // Check URL path
        if (url.length() > 0) {
            if (!url.startsWith("/") && !url.startsWith(";"))
                throw new MalformedURLException("Bad URL path: " + url);
        }
    }

    private void validate() throws MalformedURLException {
        validate(this.protocol, this.host, this.port, this.urlPath);
    }

    private static void validateHost(String h, int port)
            throws MalformedURLException {

        if (h.length() == 0) {
            if (port != 0) {
                throw new MalformedURLException("Cannot give port number " +
                                                "without host name");
            }
            return;
        }

        if (isNumericIPv6Address(h)) {
            /* We assume J2SE >= 1.4 here.  Otherwise you can't
               use the address anyway.  We can't call
               InetAddress.getByName without checking for a
               numeric IPv6 address, because we mustn't try to do
               a DNS lookup in case the address is not actually
               numeric.  */
            try {
                InetAddress.getByName(h);
            } catch (Exception e) {
                /* We should really catch UnknownHostException
                   here, but a bug in JDK 1.4 causes it to throw
                   ArrayIndexOutOfBoundsException, e.g. if the
                   string is ":".  */
                MalformedURLException bad =
                    new MalformedURLException("Bad IPv6 address: " + h);
                EnvHelp.initCause(bad, e);
                throw bad;
            }
        } else {
            /* Tiny state machine to check valid host name.  This
               checks the hostname grammar from RFC 1034 (DNS),
               page 11.  A hostname is a dot-separated list of one
               or more labels, where each label consists of
               letters, numbers, or hyphens.  A label cannot begin
               or end with a hyphen.  Empty hostnames are not
               allowed.  Note that numeric IPv4 addresses are a
               special case of this grammar.

               The state is entirely captured by the last
               character seen, with a virtual `.' preceding the
               name.  We represent any alphanumeric character by
               `a'.

               We need a special hack to check, as required by the
               RFC 2609 (SLP) grammar, that the last component of
               the hostname begins with a letter.  Respecting the
               intent of the RFC, we only do this if there is more
               than one component.  If your local hostname begins
               with a digit, we don't reject it.  */
            final int hostLen = h.length();
            char lastc = '.';
            boolean sawDot = false;
            char componentStart = 0;

            loop:
            for (int i = 0; i < hostLen; i++) {
                char c = h.charAt(i);
                boolean isAlphaNumeric = alphaNumericBitSet.get(c);
                if (lastc == '.')
                    componentStart = c;
                if (isAlphaNumeric)
                    lastc = 'a';
                else if (c == '-') {
                    if (lastc == '.')
                        break; // will throw exception
                    lastc = '-';
                } else if (c == '.') {
                    sawDot = true;
                    if (lastc != 'a')
                        break; // will throw exception
                    lastc = '.';
                } else {
                    lastc = '.'; // will throw exception
                    break;
                }
            }

            try {
                if (lastc != 'a')
                    throw randomException;
                if (sawDot && !alphaBitSet.get(componentStart)) {
                    /* Must be a numeric IPv4 address.  In addition to
                       the explicitly-thrown exceptions, we can get
                       NoSuchElementException from the calls to
                       tok.nextToken and NumberFormatException from
                       the call to Integer.parseInt.  Using exceptions
                       for control flow this way is a bit evil but it
                       does simplify things enormously.  */
                    StringTokenizer tok = new StringTokenizer(h, ".", true);
                    for (int i = 0; i < 4; i++) {
                        String ns = tok.nextToken();
                        int n = Integer.parseInt(ns);
                        if (n < 0 || n > 255)
                            throw randomException;
                        if (i < 3 && !tok.nextToken().equals("."))
                            throw randomException;
                    }
                    if (tok.hasMoreTokens())
                        throw randomException;
                }
            } catch (Exception e) {
                throw new MalformedURLException("Bad host: \"" + h + "\"");
            }
        }
    }

    private static final Exception randomException = new Exception();


    The protocol part of the Service URL.
Returns: the protocol part of the Service URL.  This is never null./**
     * <p>The protocol part of the Service URL.
     *
     * @return the protocol part of the Service URL.  This is never null.
     */
    public String getProtocol() {
        return protocol;
    }

    The host part of the Service URL.  If the Service URL was
constructed with the constructor that takes a URL string
parameter, the result is the substring specifying the host in
that URL.  If the Service URL was constructed with a
constructor that takes a separate host parameter, the result is
the string that was specified.  If that string was null, the
result is
InetAddress.getLocalHost().getHostName() if local host name
can be resolved to an IP. Else numeric IP address of an active
network interface will be used.
In either case, if the host was specified using the
[...] syntax for numeric IPv6 addresses, the
square brackets are not included in the return value here.
Returns: the host part of the Service URL.  This is never null./**
     * <p>The host part of the Service URL.  If the Service URL was
     * constructed with the constructor that takes a URL string
     * parameter, the result is the substring specifying the host in
     * that URL.  If the Service URL was constructed with a
     * constructor that takes a separate host parameter, the result is
     * the string that was specified.  If that string was null, the
     * result is
     * <code>InetAddress.getLocalHost().getHostName()</code> if local host name
     * can be resolved to an IP. Else numeric IP address of an active
     * network interface will be used.</p>
     *
     * <p>In either case, if the host was specified using the
     * <code>[...]</code> syntax for numeric IPv6 addresses, the
     * square brackets are not included in the return value here.</p>
     *
     * @return the host part of the Service URL.  This is never null.
     */
    public String getHost() {
        return host;
    }

    The port of the Service URL.  If no port was
specified, the returned value is 0.
Returns: the port of the Service URL, or 0 if none./**
     * <p>The port of the Service URL.  If no port was
     * specified, the returned value is 0.</p>
     *
     * @return the port of the Service URL, or 0 if none.
     */
    public int getPort() {
        return port;
    }

    The URL Path part of the Service URL.  This is an empty
string, or a string beginning with a slash (/), or
a string beginning with a semicolon (;).
Returns: the URL Path part of the Service URL.  This is never
null./**
     * <p>The URL Path part of the Service URL.  This is an empty
     * string, or a string beginning with a slash (<code>/</code>), or
     * a string beginning with a semicolon (<code>;</code>).
     *
     * @return the URL Path part of the Service URL.  This is never
     * null.
     */
    public String getURLPath() {
        return urlPath;
    }

    The string representation of this Service URL.  If the value
returned by this method is supplied to the
JMXServiceURL constructor, the resultant object is
equal to this one.
The host part of the returned string is the value returned by getHost(). If that value specifies a numeric IPv6 address, it is surrounded by square brackets [].
The port part of the returned string is the value returned by getPort() in its shortest decimal form. If the value is zero, it is omitted.
Returns: the string representation of this Service URL./**
     * <p>The string representation of this Service URL.  If the value
     * returned by this method is supplied to the
     * <code>JMXServiceURL</code> constructor, the resultant object is
     * equal to this one.</p>
     *
     * <p>The <code><em>host</em></code> part of the returned string
     * is the value returned by {@link #getHost()}.  If that value
     * specifies a numeric IPv6 address, it is surrounded by square
     * brackets <code>[]</code>.</p>
     *
     * <p>The <code><em>port</em></code> part of the returned string
     * is the value returned by {@link #getPort()} in its shortest
     * decimal form.  If the value is zero, it is omitted.</p>
     *
     * @return the string representation of this Service URL.
     */
    public String toString() {
        /* We don't bother synchronizing the access to toString.  At worst,
           n threads will independently compute and store the same value.  */
        if (toString != null)
            return toString;
        StringBuilder buf = new StringBuilder("service:jmx:");
        buf.append(getProtocol()).append("://");
        final String getHost = getHost();
        if (isNumericIPv6Address(getHost))
            buf.append('[').append(getHost).append(']');
        else
            buf.append(getHost);
        final int getPort = getPort();
        if (getPort != 0)
            buf.append(':').append(getPort);
        buf.append(getURLPath());
        toString = buf.toString();
        return toString;
    }

    Indicates whether some other object is equal to this one.
This method returns true if and only if obj is an
instance of JMXServiceURL whose getProtocol(), getHost(), getPort(), and getURLPath() methods return the same values as for this object. The values for getProtocol() and getHost() can differ in case without affecting equality. 
Params: obj – the reference object with which to compare.
Returns: true if this object is the same as the
obj argument; false otherwise./**
     * <p>Indicates whether some other object is equal to this one.
     * This method returns true if and only if <code>obj</code> is an
     * instance of <code>JMXServiceURL</code> whose {@link
     * #getProtocol()}, {@link #getHost()}, {@link #getPort()}, and
     * {@link #getURLPath()} methods return the same values as for
     * this object.  The values for {@link #getProtocol()} and {@link
     * #getHost()} can differ in case without affecting equality.
     *
     * @param obj the reference object with which to compare.
     *
     * @return <code>true</code> if this object is the same as the
     * <code>obj</code> argument; <code>false</code> otherwise.
     */
    public boolean equals(Object obj) {
        if (!(obj instanceof JMXServiceURL))
            return false;
        JMXServiceURL u = (JMXServiceURL) obj;
        return
            (u.getProtocol().equalsIgnoreCase(getProtocol()) &&
             u.getHost().equalsIgnoreCase(getHost()) &&
             u.getPort() == getPort() &&
             u.getURLPath().equals(getURLPath()));
    }

    public int hashCode() {
        return toString().hashCode();
    }

    /* True if this string, assumed to be a valid argument to
     * InetAddress.getByName, is a numeric IPv6 address.
     */
    private static boolean isNumericIPv6Address(String s) {
        // address contains colon if and only if it's a numeric IPv6 address
        return (s.indexOf(':') >= 0);
    }

    // like String.indexOf but returns string length not -1 if not present
    private static int indexOf(String s, char c, int fromIndex) {
        int index = s.indexOf(c, fromIndex);
        if (index < 0)
            return s.length();
        else
            return index;
    }

    private static int indexOfFirstNotInSet(String s, BitSet set,
                                            int fromIndex) {
        final int slen = s.length();
        int i = fromIndex;
        while (true) {
            if (i >= slen)
                break;
            char c = s.charAt(i);
            if (c >= 128)
                break; // not ASCII
            if (!set.get(c))
                break;
            i++;
        }
        return i;
    }

    private final static BitSet alphaBitSet = new BitSet(128);
    private final static BitSet numericBitSet = new BitSet(128);
    private final static BitSet alphaNumericBitSet = new BitSet(128);
    private final static BitSet protocolBitSet = new BitSet(128);
    private final static BitSet hostNameBitSet = new BitSet(128);
    static {
        /* J2SE 1.4 adds lots of handy methods to BitSet that would
           allow us to simplify here, e.g. by not writing loops, but
           we want to work on J2SE 1.3 too.  */

        for (char c = '0'; c <= '9'; c++)
            numericBitSet.set(c);

        for (char c = 'A'; c <= 'Z'; c++)
            alphaBitSet.set(c);
        for (char c = 'a'; c <= 'z'; c++)
            alphaBitSet.set(c);

        alphaNumericBitSet.or(alphaBitSet);
        alphaNumericBitSet.or(numericBitSet);

        protocolBitSet.or(alphaNumericBitSet);
        protocolBitSet.set('+');
        protocolBitSet.set('-');

        hostNameBitSet.or(alphaNumericBitSet);
        hostNameBitSet.set('-');
        hostNameBitSet.set('.');
    }

    The value returned by getProtocol(). /**
     * The value returned by {@link #getProtocol()}.
     */
    private String protocol;

    The value returned by getHost(). /**
     * The value returned by {@link #getHost()}.
     */
    private String host;

    The value returned by getPort(). /**
     * The value returned by {@link #getPort()}.
     */
    private int port;

    The value returned by getURLPath(). /**
     * The value returned by {@link #getURLPath()}.
     */
    private String urlPath;

    Cached result of toString(). /**
     * Cached result of {@link #toString()}.
     */
    private transient String toString;

    private static final ClassLogger logger =
        new ClassLogger("javax.management.remote.misc", "JMXServiceURL");
}
See Also:	RFC 2609, * "Service Templates and `Service:` Schemes" RFC 3111, * "Service Location Protocol Modifications for IPv6"
Since:	1.5
Params:	serviceURL – the URL string to be parsed.
Throws:	NullPointerException – if `serviceURL` is null. MalformedURLException – if `serviceURL` does not conform to the syntax for an Abstract Service URL or if it is not a valid name for a JMX Remote API service. A `JMXServiceURL` must begin with the string `"service:jmx:"` (case-insensitive). It must not contain any characters that are not printable ASCII characters.
Params:	obj – the reference object with which to compare.
Returns:	`true` if this object is the same as the `obj` argument; `false` otherwise.
/

java/ 11/ java.management/javax/management/remote/JMXServiceURL.java
