Java tutorial
/* * (This file extracted from Apache HttpClient 4.2.1, used to * provide support on Android platform - where only 4.0 is present. * Modifications are only to package/import locations to reflect location * of this code.) * * ==================================================================== * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package com.gistlabs.mechanize.util.apache; import java.net.URI; import java.nio.ByteBuffer; import java.nio.CharBuffer; import java.nio.charset.Charset; import java.util.ArrayList; import java.util.BitSet; import java.util.Collections; import java.util.List; import java.util.Scanner; import org.apache.http.Header; import org.apache.http.HeaderElement; import org.apache.http.HttpEntity; import org.apache.http.NameValuePair; import org.apache.http.annotation.Immutable; import org.apache.http.message.BasicHeaderValueParser; import org.apache.http.message.BasicNameValuePair; import org.apache.http.message.ParserCursor; import org.apache.http.util.CharArrayBuffer; /** * A collection of utilities for encoding URLs. * * @since 4.0 */ @Immutable public class URLEncodedUtils { public static final String CONTENT_TYPE = "application/x-www-form-urlencoded"; private static final String PARAMETER_SEPARATOR = "&"; private static final String NAME_VALUE_SEPARATOR = "="; /** * Returns a list of {@link NameValuePair NameValuePairs} as built from the * URI's query portion. For example, a URI of * http://example.org/path/to/file?a=1&b=2&c=3 would return a list of three * NameValuePairs, one for a=1, one for b=2, and one for c=3. * <p> * This is typically useful while parsing an HTTP PUT. * * @param uri * uri to parse * @param encoding * encoding to use while parsing the query */ public static List<NameValuePair> parse(final URI uri, final String encoding) { final String query = uri.getRawQuery(); if (query != null && query.length() > 0) { List<NameValuePair> result = new ArrayList<NameValuePair>(); Scanner scanner = new Scanner(query); parse(result, scanner, encoding); return result; } else return Collections.emptyList(); } /** * Returns a list of {@link NameValuePair NameValuePairs} as parsed from an * {@link HttpEntity}. The encoding is taken from the entity's * Content-Encoding header. * <p> * This is typically used while parsing an HTTP POST. * * @param entity * The entity to parse * @throws IOException * If there was an exception getting the entity's data. */ // public static List <NameValuePair> parse ( // final HttpEntity entity) throws IOException { // ContentType contentType = ContentType.get(entity); // if (contentType != null && contentType.getMimeType().equalsIgnoreCase(CONTENT_TYPE)) { // String content = EntityUtils.toString(entity, Consts.ASCII); // if (content != null && content.length() > 0) { // Charset charset = contentType.getCharset(); // if (charset == null) // charset = HTTP.DEF_CONTENT_CHARSET; // return parse(content, charset); // } // } // return Collections.emptyList(); // } /** * Returns true if the entity's Content-Type header is * <code>application/x-www-form-urlencoded</code>. */ public static boolean isEncoded(final HttpEntity entity) { Header h = entity.getContentType(); if (h != null) { HeaderElement[] elems = h.getElements(); if (elems.length > 0) { String contentType = elems[0].getName(); return contentType.equalsIgnoreCase(CONTENT_TYPE); } else return false; } else return false; } /** * Adds all parameters within the Scanner to the list of * <code>parameters</code>, as encoded by <code>encoding</code>. For * example, a scanner containing the string <code>a=1&b=2&c=3</code> would * add the {@link NameValuePair NameValuePairs} a=1, b=2, and c=3 to the * list of parameters. * * @param parameters * List to add parameters to. * @param scanner * Input that contains the parameters to parse. * @param charset * Encoding to use when decoding the parameters. */ public static void parse(final List<NameValuePair> parameters, final Scanner scanner, final String charset) { scanner.useDelimiter(PARAMETER_SEPARATOR); while (scanner.hasNext()) { String name = null; String value = null; String token = scanner.next(); int i = token.indexOf(NAME_VALUE_SEPARATOR); if (i != -1) { name = decodeFormFields(token.substring(0, i).trim(), charset); value = decodeFormFields(token.substring(i + 1).trim(), charset); } else name = decodeFormFields(token.trim(), charset); parameters.add(new BasicNameValuePair(name, value)); } } private static final char[] DELIM = new char[] { '&' }; /** * Returns a list of {@link NameValuePair NameValuePairs} as parsed from the given string * using the given character encoding. * * @param s * text to parse. * @param charset * Encoding to use when decoding the parameters. * * @since 4.2 */ public static List<NameValuePair> parse(final String s, final Charset charset) { if (s == null) return Collections.emptyList(); BasicHeaderValueParser parser = BasicHeaderValueParser.DEFAULT; CharArrayBuffer buffer = new CharArrayBuffer(s.length()); buffer.append(s); ParserCursor cursor = new ParserCursor(0, buffer.length()); List<NameValuePair> list = new ArrayList<NameValuePair>(); while (!cursor.atEnd()) { NameValuePair nvp = parser.parseNameValuePair(buffer, cursor, DELIM); if (nvp.getName().length() > 0) list.add(new BasicNameValuePair(decodeFormFields(nvp.getName(), charset), decodeFormFields(nvp.getValue(), charset))); } return list; } /** * Returns a String that is suitable for use as an <code>application/x-www-form-urlencoded</code> * list of parameters in an HTTP PUT or HTTP POST. * * @param parameters The parameters to include. * @param encoding The encoding to use. */ public static String format(final List<? extends NameValuePair> parameters, final String encoding) { final StringBuilder result = new StringBuilder(); for (final NameValuePair parameter : parameters) { final String encodedName = encodeFormFields(parameter.getName(), encoding); final String encodedValue = encodeFormFields(parameter.getValue(), encoding); if (result.length() > 0) result.append(PARAMETER_SEPARATOR); result.append(encodedName); if (encodedValue != null) { result.append(NAME_VALUE_SEPARATOR); result.append(encodedValue); } } return result.toString(); } /** * Returns a String that is suitable for use as an <code>application/x-www-form-urlencoded</code> * list of parameters in an HTTP PUT or HTTP POST. * * @param parameters The parameters to include. * @param charset The encoding to use. * * @since 4.2 */ public static String format(final Iterable<? extends NameValuePair> parameters, final Charset charset) { final StringBuilder result = new StringBuilder(); for (final NameValuePair parameter : parameters) { final String encodedName = encodeFormFields(parameter.getName(), charset); final String encodedValue = encodeFormFields(parameter.getValue(), charset); if (result.length() > 0) result.append(PARAMETER_SEPARATOR); result.append(encodedName); if (encodedValue != null) { result.append(NAME_VALUE_SEPARATOR); result.append(encodedValue); } } return result.toString(); } /** * Unreserved characters, i.e. alphanumeric, plus: {@code _ - ! . ~ ' ( ) *} * <p> * This list is the same as the {@code unreserved} list in * <a href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a> */ private static final BitSet UNRESERVED = new BitSet(256); /** * Punctuation characters: , ; : $ & + = * <p> * These are the additional characters allowed by userinfo. */ private static final BitSet PUNCT = new BitSet(256); /** Characters which are safe to use in userinfo, i.e. {@link #UNRESERVED} plus {@link #PUNCT}uation */ private static final BitSet USERINFO = new BitSet(256); /** Characters which are safe to use in a path, i.e. {@link #UNRESERVED} plus {@link #PUNCT}uation plus / @ */ private static final BitSet PATHSAFE = new BitSet(256); /** Characters which are safe to use in a fragment, i.e. {@link #RESERVED} plus {@link #UNRESERVED} */ private static final BitSet FRAGMENT = new BitSet(256); /** * Reserved characters, i.e. {@code ;/?:@&=+$,[]} * <p> * This list is the same as the {@code reserved} list in * <a href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a> * as augmented by * <a href="http://www.ietf.org/rfc/rfc2732.txt">RFC 2732</a> */ private static final BitSet RESERVED = new BitSet(256); /** * Safe characters for x-www-form-urlencoded data, as per java.net.URLEncoder and browser behaviour, * i.e. alphanumeric plus {@code "-", "_", ".", "*"} */ private static final BitSet URLENCODER = new BitSet(256); static { // unreserved chars // alpha characters for (int i = 'a'; i <= 'z'; i++) UNRESERVED.set(i); for (int i = 'A'; i <= 'Z'; i++) UNRESERVED.set(i); // numeric characters for (int i = '0'; i <= '9'; i++) UNRESERVED.set(i); UNRESERVED.set('_'); // these are the charactes of the "mark" list UNRESERVED.set('-'); UNRESERVED.set('.'); UNRESERVED.set('*'); URLENCODER.or(UNRESERVED); // skip remaining unreserved characters UNRESERVED.set('!'); UNRESERVED.set('~'); UNRESERVED.set('\''); UNRESERVED.set('('); UNRESERVED.set(')'); // punct chars PUNCT.set(','); PUNCT.set(';'); PUNCT.set(':'); PUNCT.set('$'); PUNCT.set('&'); PUNCT.set('+'); PUNCT.set('='); // Safe for userinfo USERINFO.or(UNRESERVED); USERINFO.or(PUNCT); // URL path safe PATHSAFE.or(UNRESERVED); PATHSAFE.set('/'); // segment separator PATHSAFE.set(';'); // param separator PATHSAFE.set(':'); // rest as per list in 2396, i.e. : @ & = + $ , PATHSAFE.set('@'); PATHSAFE.set('&'); PATHSAFE.set('='); PATHSAFE.set('+'); PATHSAFE.set('$'); PATHSAFE.set(','); RESERVED.set(';'); RESERVED.set('/'); RESERVED.set('?'); RESERVED.set(':'); RESERVED.set('@'); RESERVED.set('&'); RESERVED.set('='); RESERVED.set('+'); RESERVED.set('$'); RESERVED.set(','); RESERVED.set('['); // added by RFC 2732 RESERVED.set(']'); // added by RFC 2732 FRAGMENT.or(RESERVED); FRAGMENT.or(UNRESERVED); } private static final int RADIX = 16; /** * Emcode/escape a portion of a URL, to use with the query part ensure {@code plusAsBlank} is true. * * @param content the portion to decode * @param charset the charset to use * @param blankAsPlus if {@code true}, then convert space to '+' (e.g. for www-url-form-encoded content), otherwise leave as is. * @return */ private static String urlencode(final String content, final Charset charset, final BitSet safechars, final boolean blankAsPlus) { if (content == null) return null; StringBuilder buf = new StringBuilder(); ByteBuffer bb = charset.encode(content); while (bb.hasRemaining()) { int b = bb.get() & 0xff; if (safechars.get(b)) buf.append((char) b); else if (blankAsPlus && b == ' ') buf.append('+'); else { buf.append("%"); char hex1 = Character.toUpperCase(Character.forDigit((b >> 4) & 0xF, RADIX)); char hex2 = Character.toUpperCase(Character.forDigit(b & 0xF, RADIX)); buf.append(hex1); buf.append(hex2); } } return buf.toString(); } /** * Decode/unescape a portion of a URL, to use with the query part ensure {@code plusAsBlank} is true. * * @param content the portion to decode * @param charset the charset to use * @param plusAsBlank if {@code true}, then convert '+' to space (e.g. for www-url-form-encoded content), otherwise leave as is. * @return */ private static String urldecode(final String content, final Charset charset, final boolean plusAsBlank) { if (content == null) return null; ByteBuffer bb = ByteBuffer.allocate(content.length()); CharBuffer cb = CharBuffer.wrap(content); while (cb.hasRemaining()) { char c = cb.get(); if (c == '%' && cb.remaining() >= 2) { char uc = cb.get(); char lc = cb.get(); int u = Character.digit(uc, 16); int l = Character.digit(lc, 16); if (u != -1 && l != -1) bb.put((byte) ((u << 4) + l)); else { bb.put((byte) '%'); bb.put((byte) uc); bb.put((byte) lc); } } else if (plusAsBlank && c == '+') bb.put((byte) ' '); else bb.put((byte) c); } bb.flip(); return charset.decode(bb).toString(); } /** * Decode/unescape www-url-form-encoded content. * * @param content the content to decode, will decode '+' as space * @param charset the charset to use * @return */ private static String decodeFormFields(final String content, final String charset) { if (content == null) return null; return urldecode(content, charset != null ? Charset.forName(charset) : Consts.UTF_8, true); } /** * Decode/unescape www-url-form-encoded content. * * @param content the content to decode, will decode '+' as space * @param charset the charset to use * @return */ private static String decodeFormFields(final String content, final Charset charset) { if (content == null) return null; return urldecode(content, charset != null ? charset : Consts.UTF_8, true); } /** * Encode/escape www-url-form-encoded content. * <p> * Uses the {@link #URLENCODER} set of characters, rather than * the {@link #UNRSERVED} set; this is for compatibilty with previous * releases, URLEncoder.encode() and most browsers. * * @param content the content to encode, will convert space to '+' * @param charset the charset to use * @return */ private static String encodeFormFields(final String content, final String charset) { if (content == null) return null; return urlencode(content, charset != null ? Charset.forName(charset) : Consts.UTF_8, URLENCODER, true); } /** * Encode/escape www-url-form-encoded content. * <p> * Uses the {@link #URLENCODER} set of characters, rather than * the {@link #UNRSERVED} set; this is for compatibilty with previous * releases, URLEncoder.encode() and most browsers. * * @param content the content to encode, will convert space to '+' * @param charset the charset to use * @return */ private static String encodeFormFields(final String content, final Charset charset) { if (content == null) return null; return urlencode(content, charset != null ? charset : Consts.UTF_8, URLENCODER, true); } /** * Encode a String using the {@link #USERINFO} set of characters. * <p> * Used by URIBuilder to encode the userinfo segment. * * @param content the string to encode, does not convert space to '+' * @param charset the charset to use * @return the encoded string */ static String encUserInfo(final String content, final Charset charset) { return urlencode(content, charset, USERINFO, false); } /** * Encode a String using the {@link #FRAGMENT} set of characters. * <p> * Used by URIBuilder to encode the userinfo segment. * * @param content the string to encode, does not convert space to '+' * @param charset the charset to use * @return the encoded string */ static String encFragment(final String content, final Charset charset) { return urlencode(content, charset, FRAGMENT, false); } /** * Encode a String using the {@link #PATHSAFE} set of characters. * <p> * Used by URIBuilder to encode path segments. * * @param content the string to encode, does not convert space to '+' * @param charset the charset to use * @return the encoded string */ static String encPath(final String content, final Charset charset) { return urlencode(content, charset, PATHSAFE, false); } }