Java URL Parameter Builder canonicalize(final SortedMap sortedParamMap)

Description

Canonicalize the query string.

License

Apache License

Parameter

Parameter	Description
sortedParamMap	Parameter name-value pairs in lexicographical order.

Return

Canonical form of query string.

Declaration

private static String canonicalize(final SortedMap<String, String> sortedParamMap) 

Method Source Code

//package com.java2s;
//License from project: Apache License 

import java.net.URLDecoder;
import java.net.URLEncoder;

import java.util.*;

public class Main {
    private static final Set<String> IRRELEVANT_PARAMETERS = new HashSet<String>(3);

    /**//from  www. j  av  a2s .  c  o m
     * Canonicalize the query string.
     *
     * @param sortedParamMap Parameter name-value pairs in lexicographical order.
     * @return Canonical form of query string.
     */
    private static String canonicalize(final SortedMap<String, String> sortedParamMap) {
        if (sortedParamMap == null || sortedParamMap.isEmpty()) {
            return "";
        }

        final StringBuilder sb = new StringBuilder(100);
        for (Map.Entry<String, String> pair : sortedParamMap.entrySet()) {
            final String key = pair.getKey().toLowerCase();
            // Ignore irrelevant parameters
            if (IRRELEVANT_PARAMETERS.contains(key) || key.startsWith("utm_")) {
                continue;
            }
            if (sb.length() > 0) {
                sb.append('&');
            }
            sb.append(percentEncodeRfc3986(pair.getKey()));
            if (!pair.getValue().isEmpty()) {
                sb.append('=');
                sb.append(percentEncodeRfc3986(pair.getValue()));
            }
        }
        return sb.toString();
    }

    /**
     * <p>
     * Checks if a CharSequence is empty ("") or null.
     * </p>
     * <p>
     * <pre>
     * StringUtils.isEmpty(null)      = true
     * StringUtils.isEmpty("")        = true
     * StringUtils.isEmpty(" ")       = false
     * StringUtils.isEmpty("bob")     = false
     * StringUtils.isEmpty("  bob  ") = false
     * </pre>
     * <p>
     * <p>
     * NOTE: This method changed in Lang version 2.0. It no longer trims the
     * CharSequence. That functionality is available in isBlank().
     * </p>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if the CharSequence is empty or null
     * @since 3.0 Changed signature from isEmpty(String) to
     * isEmpty(CharSequence)
     */
    public static boolean isEmpty(CharSequence cs) {
        return cs == null || cs.length() == 0;
    }

    /**
     * Percent-encode values according the RFC 3986. The built-in Java
     * URLEncoder does not encode according to the RFC, so we make the extra
     * replacements.
     *
     * @param string Decoded string.
     * @return Encoded string per RFC 3986.
     */
    private static String percentEncodeRfc3986(String string) {
        try {
            string = string.replace("+", "%2B");
            string = URLDecoder.decode(string, "UTF-8");
            string = URLEncoder.encode(string, "UTF-8");
            return string.replace("+", "%20").replace("*", "%2A").replace("%7E", "~");
        } catch (Exception e) {
            return string;
        }
    }
}

Related

1. addParameter(Map> map, String pair)
2. canonicalize(final SortedMap sortedParamMap)
3. constructParameterString(TreeMap pPostParms)
4. convertHttpParameters(Map parameters)
5. convertToDataString(Map data)
6. convertToParameterString(Map parameterMap)