// Copyright (c) 2009, Richard Kennard
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of Richard Kennard nor the
// names of its contributors may be used to endorse or promote products
// derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY RICHARD KENNARD ''AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL RICHARD KENNARD BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package ste.web.http;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import org.apache.commons.lang3.StringUtils;
/**
* Represents a www-form-urlencoded query string containing an (ordered) list of
* parameters.
* <p>
* An instance of this class represents a query string encoded using the
* <code>www-form-urlencoded</code> encoding scheme, as defined by <a
* href="http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1">HTML
* 4.01 Specification: application/x-www-form-urlencoded</a>, and <a
* href="http://www.w3.org/TR/1999/REC-html401-19991224/appendix/notes.html#h-B.2.2">HTML
* 4.01 Specification: Ampersands in URI attribute values</a>. This is a common
* encoding scheme of the query component of a URI, though the
* <a href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396 URI specification</a>
* itself does not define a specific format for the query component.
* <p>
* This class provides static methods for <a href="#create()">creating</a>
* QueryString instances by <a href="#parse(java.lang.CharSequence)">parsing</a>
* URI and string forms. It can then be used to create, retrieve, update and
* delete parameters, and to re-apply the query string back to an existing URI.
* <p>
* <h4>Encoding and decoding</h4> QueryString automatically encodes and decodes
* parameter names and values to and from <code>www-form-urlencoded</code>
* encoding by using <code>java.net.URLEncoder</code> and
* <code>java.net.URLDecoder</code>, which follow the <a
* href="http://www.w3.org/TR/html40/appendix/notes.html#non-ascii-chars"> HTML
* 4.01 Specification: Non-ASCII characters in URI attribute values</a>
* recommendation.
* <h4>Multivalued parameters</h4> Often, parameter names are unique across the
* name/value pairs of a <code>www-form-urlencoded</code> query string. However,
* it is permitted for the same parameter name to appear in multiple name/value
* pairs, denoting that a single parameter has multiple values. This less common
* use case can lead to ambiguity when adding parameters - is the 'add' a
* 'replace' (of an existing parameter, if one with the same name already
* exists) or an 'append' (potentially creating a multivalued parameter, if one
* with the same name already exists)?
* <p>
* This requirement significantly shapes the <code>QueryString</code> API. In
* particular there are:
* <ul>
* <li><code>set</code> methods for setting a parameter, potentially replacing
* an existing value
* <li><code>append</code> methods for adding a parameter, potentially creating
* a multivalued parameter
* <li><code>get</code> methods for returning a single value, even if the
* parameter has multiple values
* <li><code>getValues</code> methods for returning multiple values
* </ul>
* <h4>Retrieving parameters</h4> QueryString can be used to parse and retrieve
* parameters from a query string by passing either a URI or a query string:
* <p>
* <code>
* URI uri = new URI("http://java.sun.com?forum=2");<br/>
* QueryString queryString = QueryString.parse(uri);<br/>
* System.out.println(queryString.get("forum"));<br/>
* </code>
* <h4>Modifying parameters</h4> QueryString can be used to set, append or
* remove parameters from a query string:
* <p>
* <code>
* URI uri = new URI("/forum/article.jsp?id=2¶=4");<br/>
* QueryString queryString = QueryString.parse(uri);<br/>
* queryString.set("id", 3);<br/>
* queryString.remove("para");<br/>
* System.out.println(queryString);<br/>
* </code>
* <p>
* When modifying parameters, the ordering of existing parameters is maintained.
* Parameters are <code>set</code> and <code>removed</code> in-place, while
* <code>appended</code> parameters are added to the end of the query string.
* <h4>Applying the Query</h4> QueryString can be used to apply a modified query
* string back to a URI, creating a new URI:
* <p>
* <code>
* URI uri = new URI("/forum/article.jsp?id=2");<br/>
* QueryString queryString = QueryString.parse(uri);<br/>
* queryString.set("id", 3);<br/>
* uri = queryString.apply(uri);<br/>
* </code>
* <p>
* When reconstructing query strings, there are two valid separator parameters
* defined by the W3C (ampersand "&" and semicolon ";"), with ampersand
* being the most common. The <code>apply</code> and <code>toString</code>
* methods both default to using an ampersand, with overloaded forms for using a
* semicolon.
* <h4>Thread Safety</h4> This implementation is not synchronized. If multiple
* threads access a query string concurrently, and at least one of the threads
* modifies the query string, it must be synchronized externally. This is
* typically accomplished by synchronizing on some object that naturally
* encapsulates the query string.
*
* @author Richard Kennard
* @version 1.2
*/
public class QueryString {
//
// Public statics
//
/**
* Enumeration of recommended www-form-urlencoded separators.
* <p>
* Recommended separators are defined by <a
* href="http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1">HTML
* 4.01 Specification: application/x-www-form-urlencoded</a> and <a
* href="http://www.w3.org/TR/html401/appendix/notes.html#h-B.2.2">HTML 4.01
* Specification: Ampersands in URI attribute values</a>.
* <p>
* <em>All</em> separators are recognised when parsing query strings.
* <em>One</em> separator may be passed to <code>toString</code> and
* <code>apply</code> when outputting query strings.
*/
public static enum Separator {
/**
* An ampersand <code>&</code> - the separator recommended by <a
* href="http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1">HTML
* 4.01 Specification: application/x-www-form-urlencoded</a>.
*/
AMPERSAND {
/**
* Returns a String representation of this Separator.
* <p>
* The String representation matches that defined by the <a
* href="http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1">HTML
* 4.01 Specification:
* application/x-www-form-urlencoded</a>.
*/
@Override
public String toString() {
return "&";
}
},
/**
* A semicolon <code>;</code> - the separator recommended by <a
* href="http://www.w3.org/TR/html401/appendix/notes.html#h-B.2.2">HTML
* 4.01 Specification: Ampersands in URI attribute values</a>.
*/
SEMICOLON {
/**
* Returns a String representation of this Separator.
* <p>
* The String representation matches that defined by the <a
* href="http://www.w3.org/TR/html401/appendix/notes.html#h-B.2.2">HTML
* 4.01 Specification: Ampersands in URI attribute
* values</a>.
*/
@Override
public String toString() {
return ";";
}
};
}
/**
* Creates an empty QueryString.
* <p>
* Calling <code>toString()</code> on the created instance will return an
* empty String.
*/
public static QueryString create() {
return new QueryString();
}
/**
* Creates a QueryString from the given Map.
* <p>
* The order the parameters are created in corresponds to the iteration
* order of the Map.
*
* @param parameterMap <code>Map</code> containing parameter names and
* values.
*/
public static QueryString create(Map<String, List<String>> parameterMap) {
QueryString queryString = new QueryString();
// Defensively copy the List<String>'s
for (Map.Entry<String, List<String>> entry : parameterMap.entrySet()) {
queryString.queryMap.put(entry.getKey(), new ArrayList<String>(entry.getValue()));
}
return queryString;
}
/**
* Creates a QueryString by parsing the given query string.
* <p>
* This method assumes the given string is the
* <code>www-form-urlencoded</code> query component of a URI. When parsing,
* all <a href="UrlEncodedQueryString.Separator.html">Separators</a> are
* recognised.
* <p>
* The result of calling this method with a string that is not
* <code>www-form-urlencoded</code> (eg. passing an entire URI, not just its
* query string) will likely be mismatched parameter names.
*
* @param query query string to be parsed
*/
public static QueryString parse(final CharSequence query) {
QueryString queryString = new QueryString();
// Note: import to call appendOrSet with 'true', in
// case the given query contains multi-valued parameters
queryString.appendOrSet(query, true);
return queryString;
}
/**
* Creates a QueryString by extracting and parsing the query component from
* the given URI.
* <p>
* This method assumes the query component is
* <code>www-form-urlencoded</code>. When parsing, all separators from the
* Separators enum are recognised.
* <p>
* The result of calling this method with a query component that is not
* <code>www-form-urlencoded</code> will likely be mismatched parameter
* names.
*
* @param uri URI to be parsed
*/
public static QueryString parse(final URI uri) {
// Note: use uri.getRawQuery, not uri.getQuery, in case the
// query parameters contain encoded ampersands (%26)
return parse(uri.getRawQuery());
}
//
// Private statics
//
/**
* Separators to honour when parsing query strings.
* <p>
* <em>All</em> Separators are recognized when parsing parameters,
* regardless of what the user later nominates as their
* <code>toString</code> output parameter.
*/
private static final String PARSE_PARAMETER_SEPARATORS = String.valueOf(Separator.AMPERSAND) + Separator.SEMICOLON;
//
// Private members
//
/**
* Map of query parameters.
*/
// Note: we initialize this Map upon object creation because, realistically, it
// is always going to be needed (eg. there is little point lazy-initializing it)
private final Map<String, List<String>> queryMap = new LinkedHashMap<String, List<String>>();
//
// Public methods
//
/**
* Returns the value of the named parameter as a String. Returns
* <code>null</code> if the parameter does not exist, or exists but has a
* <code>null</code> value (see {@link #contains
* contains}).
* <p>
* You should only use this method when you are sure the parameter has only
* one value. If the parameter might have more than one value, use <a
* href="#getValues(java.lang.String)">getValues</a>.
* <p>
* If you use this method with a multivalued parameter, the value returned
* is equal to the first value in the List returned by
* <a href="#getValues(java.lang.String)">getValues</a>.
*
* @param name <code>String</code> specifying the name of the parameter
* @return <code>String</code> representing the single value of the
* parameter, or <code>null</code> if the parameter does not exist or exists
* but with a null value (see {@link #contains contains}).
*/
public String get(final String name) {
List<String> parameters = getValues(name);
if (parameters == null || parameters.isEmpty()) {
return null;
}
return parameters.get(0);
}
/**
* Returns whether the named parameter exists.
* <p>
* This can be useful to distinguish between a parameter not existing, and a
* parameter existing but with a <code>null</code> value (eg.
* <code>foo=1&bar</code>). This is distinct from a parameter existing with
* a value of the empty String (eg. <code>foo=1&bar=</code>).
*/
public boolean contains(final String name) {
return this.queryMap.containsKey(name);
}
/**
* Returns a <code>Set</code> of <code>String</code> objects containing the
* names of the parameters. If there are no parameters, the method returns
* an empty Set. For names with multiple values, only one copy of the name
* is returned.
*
* @return a <code>Set</code> of <code>String</code> objects, each String
* containing the name of a parameter; or an empty Set if there are no
* parameters
*/
public Set<String> getNames() {
return this.queryMap.keySet();
}
/**
* Returns a List of <code>String</code> objects containing all of the
* values the named parameter has, or <code>null</code> if the parameter
* does not exist.
* <p>
* If the parameter has a single value, the List has a size of 1.
*
* @param name name of the parameter to retrieve
* @return a List of String objects containing the parameter's values, or
* <code>null</code> if the paramater does not exist
*/
public List<String> getValues(final String name) {
return this.queryMap.get(name);
}
/**
* Returns a mutable <code>Map</code> of the query parameters.
*
* @return <code>Map</code> containing parameter names as keys and parameter
* values as map values. The keys in the parameter map are of type
* <code>String</code>. The values in the parameter map are Lists of type
* <code>String</code>, and their ordering is consistent with their ordering
* in the query string. Will never return <code>null</code>.
*/
public Map<String, List<String>> getMap() {
LinkedHashMap<String, List<String>> map = new LinkedHashMap<String, List<String>>();
// Defensively copy the List<String>'s
for (Map.Entry<String, List<String>> entry : this.queryMap.entrySet()) {
List<String> listValues = entry.getValue();
map.put(entry.getKey(), new ArrayList<String>(listValues));
}
return map;
}
/**
* Sets a query parameter.
* <p>
* If one or more parameters with this name already exist, they will be
* replaced with a single parameter with the given value. If no such
* parameters exist, one will be added.
*
* @param name name of the query parameter
* @param value value of the query parameter. If <code>null</code>, the
* parameter is removed
* @return a reference to this object
*/
public QueryString set(final String name, final String value) {
appendOrSet(name, value, false);
return this;
}
/**
* Sets a query parameter.
* <p>
* If one or more parameters with this name already exist, they will be
* replaced with a single parameter with the given value. If no such
* parameters exist, one will be added.
* <p>
* This version of <code>set</code> accepts a <code>Number</code> suitable
* for auto-boxing. For example:
* <p>
* <code>
* queryString.set( "id", 3 );<br/>
* </code>
*
* @param name name of the query parameter
* @param value value of the query parameter. If <code>null</code>, the
* parameter is removed
* @return a reference to this object
*/
public QueryString set(final String name, final Number value) {
if (value == null) {
remove(name);
return this;
}
appendOrSet(name, value.toString(), false);
return this;
}
/**
* Sets query parameters from a <code>www-form-urlencoded</code> string.
* <p>
* The given string is assumed to be in <code>www-form-urlencoded</code>
* format. The result of passing a string not in
* <code>www-form-urlencoded</code> format (eg. passing an entire URI, not
* just its query string) will likely be mismatched parameter names.
* <p>
* The given string is parsed into named parameters, and each is added to
* the existing parameters. If a parameter with the same name already
* exists, it is replaced with a single parameter with the given value. If
* the same parameter name appears more than once in the given string, it is
* stored as a multivalued parameter. When parsing, all <a
* href="UrlEncodedQueryString.Separator.html">Separators</a> are
* recognised.
*
* @param query <code>www-form-urlencoded</code> string. If
* <code>null</code>, does nothing
* @return a reference to this object
*/
public QueryString set(final String query) {
appendOrSet(query, false);
return this;
}
/**
* Appends a query parameter.
* <p>
* If one or more parameters with this name already exist, their value will
* be preserved and the given value will be stored as a multivalued
* parameter. If no such parameters exist, one will be added.
*
* @param name name of the query parameter
* @param value value of the query parameter. If <code>null</code>, does
* nothing
* @return a reference to this object
*/
public QueryString append(final String name, final String value) {
appendOrSet(name, value, true);
return this;
}
/**
* Appends a query parameter.
* <p>
* If one or more parameters with this name already exist, their value will
* be preserved and the given value will be stored as a multivalued
* parameter. If no such parameters exist, one will be added.
* <p>
* This version of <code>append</code> accepts a <code>Number</code>
* suitable for auto-boxing. For example:
* <p>
* <code>
* queryString.append( "id", 3 );<br/>
* </code>
*
* @param name name of the query parameter
* @param value value of the query parameter. If <code>null</code>, does
* nothing
* @return a reference to this object
*/
public QueryString append(final String name, final Number value) {
appendOrSet(name, value.toString(), true);
return this;
}
/**
* Appends query parameters from a <code>www-form-urlencoded</code> string.
* <p>
* The given string is assumed to be in <code>www-form-urlencoded</code>
* format. The result of passing a string not in
* <code>www-form-urlencoded</code> format (eg. passing an entire URI, not
* just its query string) will likely be mismatched parameter names.
* <p>
* The given string is parsed into named parameters, and appended to the
* existing parameters. If a parameter with the same name already exists, or
* if the same parameter name appears more than once in the given string, it
* is stored as a multivalued parameter. When parsing, all <a
* href="UrlEncodedQueryString.Separator.html">Separators</a> are
* recognised.
*
* @param query <code>www-form-urlencoded</code> string. If
* <code>null</code>, does nothing
* @return a reference to this object
*/
public QueryString append(final String query) {
appendOrSet(query, true);
return this;
}
/**
* Returns whether the query string is empty.
*
* @return true if the query string has no parameters
*/
public boolean isEmpty() {
return queryMap.isEmpty();
}
/**
* Removes the named query parameter.
* <p>
* If the parameter has multiple values, all its values are removed.
*
* @param name name of the parameter to remove
* @return a reference to this object
*/
public QueryString remove(final String name) {
appendOrSet(name, null, false);
return this;
}
/**
* Applies the query string to the given URI.
* <p>
* A copy of the given URI is taken and its existing query string, if there
* is one, is replaced. The query string parameters are separated by
* <code>Separator.Ampersand</code>.
*
* @param uri URI to copy and update
* @return a copy of the given URI, with an updated query string
*/
public URI apply(URI uri) {
return apply(uri, Separator.AMPERSAND);
}
/**
* Applies the query string to the given URI, using the given separator
* between parameters.
* <p>
* A copy of the given URI is taken and its existing query string, if there
* is one, is replaced. The query string parameters are separated using the
* given <code>Separator</code>.
*
* @param uri URI to copy and update
* @param separator separator to use between parameters
* @return a copy of the given URI, with an updated query string
*/
public URI apply(URI uri, Separator separator) {
// Note this code is essentially a copy of 'java.net.URI.defineString',
// which is private. We cannot use the 'new URI( scheme, userInfo, ... )' or
// 'new URI( scheme, authority, ... )' constructors because they double
// encode the query string using 'java.net.URI.quote'
StringBuilder builder = new StringBuilder();
if (uri.getScheme() != null) {
builder.append(uri.getScheme());
builder.append(':');
}
if (uri.getHost() != null) {
builder.append("//");
if (uri.getUserInfo() != null) {
builder.append(uri.getUserInfo());
builder.append('@');
}
builder.append(uri.getHost());
if (uri.getPort() != -1) {
builder.append(':');
builder.append(uri.getPort());
}
} else if (uri.getAuthority() != null) {
builder.append("//");
builder.append(uri.getAuthority());
}
if (uri.getPath() != null) {
builder.append(uri.getPath());
}
String query = toString(separator);
if (query.length() != 0) {
builder.append('?');
builder.append(query);
}
if (uri.getFragment() != null) {
builder.append('#');
builder.append(uri.getFragment());
}
try {
return new URI(builder.toString());
} catch (URISyntaxException e) {
// Can never happen, as the given URI will always be valid,
// and getQuery() will always return a valid query string
throw new RuntimeException(e);
}
}
/**
* Compares the specified object with this QueryString for equality.
* <p>
* Returns <code>true</code> if the given object is also a QueryString and
* the two UrlEncodedQueryStrings have the same parameters. More formally,
* two UrlEncodedQueryStrings
* <code>t1</code> and <code>t2</code> represent the same QueryString if
* <code>t1.toString().equals(t2.toString())</code>. This ensures that the
* <code>equals</code> method checks the ordering, as well as the existence,
* of every parameter.
* <p>
* Clients interested only in the existence, not the ordering, of parameters
* are recommended to use <code>getMap().equals</code>.
* <p>
* This implementation first checks if the specified object is this
* QueryString; if so it returns <code>true</code>. Then, it checks if the
* specified object is a QueryString whose toString() is identical to the
* toString() of this QueryString; if not, it returns <code>false</code>.
* Otherwise, it returns <code>true</code>
*
* @param obj object to be compared for equality with this QueryString.
* @return <code>true</code> if the specified object is equal to this
* QueryString.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof QueryString)) {
return false;
}
String query = toString();
String thatQuery = ((QueryString) obj).toString();
return query.equals(thatQuery);
}
/**
* Returns a hash code value for the QueryString.
* <p>
* The hash code of the QueryString is defined to be the hash code of the
* <code>String</code> returned by toString(). This ensures the ordering, as
* well as the existence, of parameters is taken into account.
* <p>
* Clients interested only in the existence, not the ordering, of parameters
* are recommended to use <code>getMap().hashCode</code>.
*
* @return a hash code value for this QueryString.
*/
@Override
public int hashCode() {
return toString().hashCode();
}
/**
* Returns a <code>www-form-urlencoded</code> string of the query
* parameters.
* <p>
* The HTML specification recommends two parameter separators in <a
* href="http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1">HTML
* 4.01 Specification: application/x-www-form-urlencoded</a> and <a
* href="http://www.w3.org/TR/1999/REC-html401-19991224/appendix/notes.html#h-B.2.2">HTML
* 4.01 Specification: Ampersands in URI attribute values</a>. Of those, the
* ampersand is the more commonly used and this method defaults to that.
*
* @return <code>www-form-urlencoded</code> string, or <code>null</code> if
* there are no parameters.
*/
@Override
public String toString() {
return toString(Separator.AMPERSAND);
}
/**
* Returns a <code>www-form-urlencoded</code> string of the query
* parameters, using the given separator between parameters.
*
* @param separator separator to use between parameters
* @return <code>www-form-urlencoded</code> string, or an empty String if
* there are no parameters
*/
// Note: this method takes a Separator, not just any String. Taking any String may
// be useful in some circumstances (eg. you could pass '&' to generate query
// strings for use in HTML pages) but would break the implied contract between
// toString() and parse() (eg. you can always parse() what you toString() ).
//
// It was thought better to leave it to the user to explictly break this contract
// (eg. toString().replaceAll( '&', '&' ))
public String toString(Separator separator) {
StringBuilder builder = new StringBuilder();
for (String name : this.queryMap.keySet()) {
for (String value : this.queryMap.get(name)) {
if (builder.length() != 0) {
builder.append(separator);
}
// Encode names and values. Do this in toString(), rather than
// append/set, so that the Map always contains the
// raw, unencoded values
try {
builder.append(URLEncoder.encode(name, "UTF-8"));
if (value != null) {
builder.append('=');
builder.append(URLEncoder.encode(value, "UTF-8"));
}
} catch (UnsupportedEncodingException e) {
// Should never happen. UTF-8 should always be available
// according to Java spec
throw new RuntimeException(e);
}
}
}
return builder.toString();
}
// --------------------------------------------------------- private methods
/**
* Private constructor.
* <p>
* Clients should use one of the <code>create</code> or <code>parse</code>
* methods to create a <code>UrlEncodedQueryString</code>.
*/
private QueryString() {
// Can never be called
}
/**
* Helper method for append and set
*
* @param name the parameter's name
* @param value the parameter's value
* @param append whether to append (or set)
*/
private void appendOrSet(final String name, final String value, final boolean append) {
if (name == null) {
throw new NullPointerException("name");
}
// If we're appending, and there's an existing parameter...
if (append) {
List<String> listValues = this.queryMap.get(name);
// ...add to it
if (listValues != null) {
listValues.add(value);
return;
}
} // ...otherwise, if we're setting and the value is null...
else if (value == null) {
// ...remove it
this.queryMap.remove(name);
return;
}
// ...otherwise, create a new one
List<String> listValues = new ArrayList<String>();
listValues.add(value);
this.queryMap.put(name, listValues);
}
/**
* Helper method for append and set
*
* @param query <code>www-form-urlencoded</code> string
* @param append whether to append (or set)
*/
private void appendOrSet(final CharSequence parameters, final boolean append) {
if ((parameters == null) || StringUtils.isBlank(parameters.toString())) {
return;
}
// Note we always parse using PARSE_PARAMETER_SEPARATORS, regardless
// of what the user later nominates as their output parameter
// separator using toString()
StringTokenizer tokenizer = new StringTokenizer(parameters.toString(), PARSE_PARAMETER_SEPARATORS);
Set<String> setAlreadyParsed = null;
while (tokenizer.hasMoreTokens()) {
String parameter = tokenizer.nextToken();
int indexOf = parameter.indexOf('=');
String name;
String value;
try {
if (indexOf == -1) {
name = parameter;
value = null;
} else {
name = parameter.substring(0, indexOf);
value = parameter.substring(indexOf + 1);
}
// Decode the name if necessary (i.e. %70age=1 becomes page=1)
name = URLDecoder.decode(name, "UTF-8");
// When not appending, the first time we see a given
// name it is important to remove it from the existing
// parameters
if (!append) {
if (setAlreadyParsed == null) {
setAlreadyParsed = new HashSet<String>();
}
if (!setAlreadyParsed.contains(name)) {
remove(name);
}
setAlreadyParsed.add(name);
}
if (value != null) {
value = URLDecoder.decode(value, "UTF-8");
}
appendOrSet(name, value, true);
} catch (UnsupportedEncodingException e) {
// Should never happen. UTF-8 should always be available
// according to Java spec
throw new RuntimeException(e);
}
}
}
}