Java tutorial
package com.sina.cloudstorage.util; /* * ==================================================================== * 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/>. * */ import java.io.IOException; import java.io.UnsupportedEncodingException; import java.net.URI; import java.net.URLDecoder; import java.net.URLEncoder; import java.nio.charset.Charset; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.Scanner; import org.apache.http.annotation.Immutable; import org.apache.http.entity.ContentType; import org.apache.http.Consts; import org.apache.http.Header; import org.apache.http.HeaderElement; import org.apache.http.HttpEntity; import org.apache.http.NameValuePair; import org.apache.http.message.BasicHeaderValueParser; import org.apache.http.message.BasicNameValuePair; import org.apache.http.message.ParserCursor; import org.apache.http.protocol.HTTP; import org.apache.http.util.CharArrayBuffer; import org.apache.http.util.EntityUtils; /** * 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 != null ? contentType.getCharset() : null; 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 = decode(token.substring(0, i).trim(), charset); value = decode(token.substring(i + 1).trim(), charset); } else { name = decode(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(decode(nvp.getName(), charset), decode(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 = encode(parameter.getName(), encoding); final String encodedValue = encode(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 = encode(parameter.getName(), charset); final String encodedValue = encode(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(); } private static String decode(final String content, final String charset) { if (content == null) { return null; } try { return URLDecoder.decode(content, charset != null ? charset : HTTP.DEF_CONTENT_CHARSET.name()); } catch (UnsupportedEncodingException ex) { throw new IllegalArgumentException(ex); } } private static String decode(final String content, final Charset charset) { if (content == null) { return null; } return decode(content, charset != null ? charset.name() : null); } private static String encode(final String content, final String charset) { if (content == null) { return null; } try { return URLEncoder.encode(content, charset != null ? charset : HTTP.DEF_CONTENT_CHARSET.name()); } catch (UnsupportedEncodingException ex) { throw new IllegalArgumentException(ex); } } private static String encode(final String content, final Charset charset) { if (content == null) { return null; } return encode(content, charset != null ? charset.name() : null); } }