https://projects.eclipse.org/projects/ee4j.jersey/jersey-common: Jersey core common packages (Eclipse Foundation) 
/*
 * Copyright (c) 2012, 2019 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.jersey.uri.internal;

import org.glassfish.jersey.internal.LocalizationMessages;


Parser for string URI with template parameters which produces URIs from Strings. Example of parsed uri: "http://user@{host}:{port}/a/{path}?query=1#fragment". The parser is not thread safe. 
Author:Paul Sandoz, Marek Potociar
/**
 * Parser for string URI with template parameters which produces {@link java.net.URI URIs} from Strings.
 * Example of parsed uri: {@code "http://user@{host}:{port}/a/{path}?query=1#fragment"}.
 * The parser is not thread safe.
 *
 * @author Paul Sandoz
 * @author Marek Potociar
 */
class UriParser {
    private static final String ERROR_STATE = LocalizationMessages.URI_PARSER_NOT_EXECUTED();
    private final String input;
    private CharacterIterator ci;
    private String scheme;
    private String userInfo;
    private String host;
    private String port;
    private String query;
    private String path;
    private String fragment;
    private String ssp;
    private String authority;
    private boolean opaque;
    private boolean parserExecuted;


    
Creates new parser initialized with uri. 
Params:
  • uri – String with URI to be parsed. May contain template parameters.
/**
     * Creates new parser initialized with {@code uri}.
     *
     * @param uri String with URI to be parsed. May contain template parameters.
     */
    UriParser(String uri) {
        this.input = uri;
    }

    private String parseComponentWithIP(String delimiters, boolean mayEnd) {
        return parseComponent(delimiters, mayEnd, true);
    }


    private String parseComponent(String delimiters, boolean mayEnd) {
        return parseComponent(delimiters, mayEnd, false);
    }

    
Parses the URI component. Parsing starts at position of the first character of component and ends with position of one of the delimiters. The string and current position is taken from the CharacterIterator. 
Params:
  • delimiters – String with delimiters which terminates the component.
  • mayEnd –     True if component might be the last part of the URI.
  • isIp –       True if the component might contain IPv6 address.
Returns:Extracted component.
/**
     * Parses the URI component. Parsing starts at position of the first character of
     * component and ends with position of one of the delimiters. The string and current
     * position is taken from the {@link org.glassfish.jersey.uri.internal.CharacterIterator}.
     *
     * @param delimiters String with delimiters which terminates the component.
     * @param mayEnd     True if component might be the last part of the URI.
     * @param isIp       True if the component might contain IPv6 address.
     * @return Extracted component.
     */
    private String parseComponent(String delimiters, boolean mayEnd, boolean isIp) {

        int curlyBracketsCount = 0;
        int squareBracketsCount = 0;

        StringBuilder sb = new StringBuilder();

        boolean endOfInput = false;
        char c = ci.current();
        while (!endOfInput) {
            if (c == '{') {
                curlyBracketsCount++;
                sb.append(c);
            } else if (c == '}') {
                curlyBracketsCount--;
                sb.append(c);
            } else if (isIp && c == '[') {
                squareBracketsCount++;
                sb.append(c);
            } else if (isIp && c == ']') {
                squareBracketsCount--;
                sb.append(c);

                // test IPv6 or regular expressions in the template params
            } else if ((!isIp || squareBracketsCount == 0) && (curlyBracketsCount == 0)
                       && (delimiters != null && delimiters.indexOf(c) >= 0)) {
                return sb.length() == 0 ? null : sb.toString();
            } else {
                sb.append(c);
            }
            endOfInput = !ci.hasNext();
            if (!endOfInput) {
                c = ci.next();
            }
        }
        if (mayEnd) {
            return sb.length() == 0 ? null : sb.toString();
        }
        throw new IllegalArgumentException(LocalizationMessages.URI_PARSER_COMPONENT_DELIMITER(delimiters, ci.pos()));
    }

    
Parses the input string URI. After calling this method The result components can be retrieved by calling appropriate getter methods like getHost(), getPort(), etc. 
/**
     * Parses the input string URI. After calling this method The result components can be retrieved by calling appropriate
     * getter methods like {@link #getHost()}, {@link #getPort()}, etc.
     */
    public void parse() {
        this.parserExecuted = true;
        this.ci = new CharacterIterator(input);
        if (!ci.hasNext()) {
            // empty string on input -> set both SSP and path to ""
            this.path = "";
            this.ssp = "";
            return;
        }
        ci.next();
        String comp = parseComponent(":/?#", true);

        if (ci.hasNext()) {
            this.ssp = ci.getInput().substring(ci.pos() + 1);
        }

        this.opaque = false;
        if (ci.current() == ':') {
            // absolute
            if (comp == null) {
                throw new IllegalArgumentException(LocalizationMessages.URI_PARSER_SCHEME_EXPECTED(ci.pos(), input));
            }
            scheme = comp;
            if (!ci.hasNext()) {
                // empty SSP/path -> set both SSP and path to ""
                this.path = "";
                this.ssp = "";
                return;
            }
            char c = ci.next();
            if (c == '/') {
                // hierarchical
                parseHierarchicalUri();

            } else {
                // opaque
                this.opaque = true;
            }
        } else {
            ci.setPosition(0);
            // relative
            if (ci.current() == '/') {
                parseHierarchicalUri();
            } else {
                parsePath();
            }
        }
    }

    private void parseHierarchicalUri() {
        if (ci.hasNext() && ci.peek() == '/') {
            // authority
            ci.next();
            ci.next();
            parseAuthority();

        }
        if (!ci.hasNext()) {
            if (ci.current() == '/') {
                path = "/";
            }
            return;
        }
        parsePath();
    }

    private void parseAuthority() {
        int start = ci.pos();
        String comp = parseComponentWithIP("@/?#", true);
        if (ci.current() == '@') {
            this.userInfo = comp;
            if (!ci.hasNext()) {
                return;
            }
            ci.next();
            comp = parseComponentWithIP(":/?#", true);
        } else {
            ci.setPosition(start);
            comp = parseComponentWithIP("@:/?#", true);
        }

        this.host = comp;

        if (ci.current() == ':') {
            if (!ci.hasNext()) {
                return;
            }
            ci.next();
            this.port = parseComponent("/?#", true);
        }
        this.authority = ci.getInput().substring(start, ci.pos());
        if (this.authority.length() == 0) {
            this.authority = null;
        }


    }


    private void parsePath() {
        this.path = parseComponent("?#", true);


        if (ci.current() == '?') {
            if (!ci.hasNext()) {
                return;
            }
            ci.next(); // skip ?

            this.query = parseComponent("#", true);
        }

        if (ci.current() == '#') {
            if (!ci.hasNext()) {
                return;
            }
            ci.next(); // skip #

            this.fragment = parseComponent(null, true);
        }
    }

    
Returns parsed scheme specific part. The method must be called before executing this method. 
Returns:Scheme specific part.
/**
     * Returns parsed scheme specific part. The {@link #parse() method} must be called before executing this method.
     *
     * @return Scheme specific part.
     */
    public String getSsp() {
        if (!parserExecuted) {
            throw new IllegalStateException(ERROR_STATE);
        }
        return ssp;
    }

    
Returns parsed scheme component. The method must be called before executing this method. 
Returns:Scheme.
/**
     * Returns parsed scheme component. The {@link #parse() method} must be called before executing this method.
     *
     * @return Scheme.
     */
    public String getScheme() {
        if (!parserExecuted) {
            throw new IllegalStateException(ERROR_STATE);
        }
        return scheme;
    }

    
Returns parsed user info component. The method must be called before executing this method. 
Returns:User info.
/**
     * Returns parsed user info component. The {@link #parse() method} must be called before executing this method.
     *
     * @return User info.
     */
    public String getUserInfo() {
        if (!parserExecuted) {
            throw new IllegalStateException(ERROR_STATE);
        }
        return userInfo;
    }

    
Returns parsed host component. The method must be called before executing this method. 
Returns:Host.
/**
     * Returns parsed host component. The {@link #parse() method} must be called before executing this method.
     *
     * @return Host.
     */
    public String getHost() {
        if (!parserExecuted) {
            throw new IllegalStateException(ERROR_STATE);
        }
        return host;
    }

    
Returns parsed port component. The method must be called before executing this method. 
Returns:Port.
/**
     * Returns parsed port component. The {@link #parse() method} must be called before executing this method.
     *
     * @return Port.
     */
    public String getPort() {
        if (!parserExecuted) {
            throw new IllegalStateException(ERROR_STATE);
        }
        return port;
    }

    
Returns parsed query component. The method must be called before executing this method. 
Returns:Query.
/**
     * Returns parsed query component. The {@link #parse() method} must be called before executing this method.
     *
     * @return Query.
     */
    public String getQuery() {
        if (!parserExecuted) {
            throw new IllegalStateException(ERROR_STATE);
        }
        return query;
    }

    
Returns parsed path component. The method must be called before executing this method. 
Returns:Path.
/**
     * Returns parsed path component. The {@link #parse() method} must be called before executing this method.
     *
     * @return Path.
     */
    public String getPath() {
        if (!parserExecuted) {
            throw new IllegalStateException(ERROR_STATE);
        }
        return path;
    }

    
Returns parsed fragment component. The method must be called before executing this method. 
Returns:Fragment.
/**
     * Returns parsed fragment component. The {@link #parse() method} must be called before executing this method.
     *
     * @return Fragment.
     */
    public String getFragment() {
        if (!parserExecuted) {
            throw new IllegalStateException(ERROR_STATE);
        }
        return fragment;
    }

    
Returns parsed authority component. The method must be called before executing this method. 
Returns:Authority.
/**
     * Returns parsed authority component. The {@link #parse() method} must be called before executing this method.
     *
     * @return Authority.
     */
    public String getAuthority() {
        if (!parserExecuted) {
            throw new IllegalStateException(ERROR_STATE);
        }
        return authority;
    }

    
Returns whether the input string URI is opaque. The method must be called before executing this method. 
Returns:True if the uri is opaque.
/**
     * Returns whether the input string URI is opaque. The {@link #parse() method} must be called before executing this method.
     *
     * @return True if the uri is opaque.
     */
    public boolean isOpaque() {
        if (!parserExecuted) {
            throw new IllegalStateException(ERROR_STATE);
        }
        return opaque;
    }
}