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A library jar that provides APIs for Applications written for the Google Android Platform.

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/*
 *  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.
 */

package libcore.net;

import java.io.ByteArrayOutputStream;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;

/**
 * Encodes and decodes {@code application/x-www-form-urlencoded} content.
 * Subclasses define exactly which characters are legal.
 *
 * 

By default, UTF-8 is used to encode escaped characters. A single input * character like "\u0080" may be encoded to multiple octets like %C2%80. */ public abstract class UriCodec { /** * Returns true if {@code c} does not need to be escaped. */ protected abstract boolean isRetained(char c); /** * Throws if {@code s} is invalid according to this encoder. */ public final String validate(String uri, int start, int end, String name) throws URISyntaxException { for (int i = start; i < end; ) { char ch = uri.charAt(i); if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || (ch >= '0' && ch <= '9') || isRetained(ch)) { i++; } else if (ch == '%') { if (i + 2 >= end) { throw new URISyntaxException(uri, "Incomplete % sequence in " + name, i); } int d1 = hexToInt(uri.charAt(i + 1)); int d2 = hexToInt(uri.charAt(i + 2)); if (d1 == -1 || d2 == -1) { throw new URISyntaxException(uri, "Invalid % sequence: " + uri.substring(i, i + 3) + " in " + name, i); } i += 3; } else { throw new URISyntaxException(uri, "Illegal character in " + name, i); } } return uri.substring(start, end); } /** * Throws if {@code s} contains characters that are not letters, digits or * in {@code legal}. */ public static void validateSimple(String s, String legal) throws URISyntaxException { for (int i = 0; i < s.length(); i++) { char ch = s.charAt(i); if (!((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || (ch >= '0' && ch <= '9') || legal.indexOf(ch) > -1)) { throw new URISyntaxException(s, "Illegal character", i); } } } /** * Encodes {@code s} and appends the result to {@code builder}. * * @param isPartiallyEncoded true to fix input that has already been * partially or fully encoded. For example, input of "hello%20world" is * unchanged with isPartiallyEncoded=true but would be double-escaped to * "hello%2520world" otherwise. */ private void appendEncoded(StringBuilder builder, String s, Charset charset, boolean isPartiallyEncoded) { if (s == null) { throw new NullPointerException("s == null"); } int escapeStart = -1; for (int i = 0; i < s.length(); i++) { char c = s.charAt(i); if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || isRetained(c) || (c == '%' && isPartiallyEncoded)) { if (escapeStart != -1) { appendHex(builder, s.substring(escapeStart, i), charset); escapeStart = -1; } if (c == '%' && isPartiallyEncoded) { // this is an encoded 3-character sequence like "%20" builder.append(s, i, Math.min(i + 3, s.length())); i += 2; } else if (c == ' ') { builder.append('+'); } else { builder.append(c); } } else if (escapeStart == -1) { escapeStart = i; } } if (escapeStart != -1) { appendHex(builder, s.substring(escapeStart, s.length()), charset); } } public final String encode(String s, Charset charset) { // Guess a bit larger for encoded form StringBuilder builder = new StringBuilder(s.length() + 16); appendEncoded(builder, s, charset, false); return builder.toString(); } public final void appendEncoded(StringBuilder builder, String s) { appendEncoded(builder, s, StandardCharsets.UTF_8, false); } public final void appendPartiallyEncoded(StringBuilder builder, String s) { appendEncoded(builder, s, StandardCharsets.UTF_8, true); } /** * @param convertPlus true to convert '+' to ' '. * @param throwOnFailure true to throw an IllegalArgumentException on * invalid escape sequences; false to replace them with the replacement * character (U+fffd). */ public static String decode(String s, boolean convertPlus, Charset charset, boolean throwOnFailure) { if (s.indexOf('%') == -1 && (!convertPlus || s.indexOf('+') == -1)) { return s; } StringBuilder result = new StringBuilder(s.length()); ByteArrayOutputStream out = new ByteArrayOutputStream(); for (int i = 0; i < s.length();) { char c = s.charAt(i); if (c == '%') { do { int d1, d2; if (i + 2 < s.length() && (d1 = hexToInt(s.charAt(i + 1))) != -1 && (d2 = hexToInt(s.charAt(i + 2))) != -1) { out.write((byte) ((d1 << 4) + d2)); } else if (throwOnFailure) { throw new IllegalArgumentException("Invalid % sequence at " + i + ": " + s); } else { byte[] replacement = "\ufffd".getBytes(charset); out.write(replacement, 0, replacement.length); } i += 3; } while (i < s.length() && s.charAt(i) == '%'); result.append(new String(out.toByteArray(), charset)); out.reset(); } else { if (convertPlus && c == '+') { c = ' '; } result.append(c); i++; } } return result.toString(); } /** * Like {@link Character#digit}, but without support for non-ASCII * characters. */ private static int hexToInt(char c) { if ('0' <= c && c <= '9') { return c - '0'; } else if ('a' <= c && c <= 'f') { return 10 + (c - 'a'); } else if ('A' <= c && c <= 'F') { return 10 + (c - 'A'); } else { return -1; } } public static String decode(String s) { return decode(s, false, StandardCharsets.UTF_8, true); } private static void appendHex(StringBuilder builder, String s, Charset charset) { for (byte b : s.getBytes(charset)) { appendHex(builder, b); } } private static void appendHex(StringBuilder sb, byte b) { sb.append('%'); sb.append(Byte.toHexString(b, true)); } }





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