Java tutorial
/** * Copyright 2014 Opower, Inc. * Licensed 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 com.opower.rest.client.generator.util; import com.google.common.base.Optional; import com.google.common.collect.ImmutableMap; import com.google.common.collect.MapMaker; import javax.ws.rs.core.CacheControl; import javax.ws.rs.core.Cookie; import javax.ws.rs.core.EntityTag; import javax.ws.rs.core.MediaType; import javax.ws.rs.core.NewCookie; import java.net.URI; import java.util.HashMap; import java.util.List; import java.util.Locale; import java.util.concurrent.ConcurrentMap; public class StringConverters { private static ConcurrentMap<Class<?>, StringConverter<?>> CONVERTERS; public static <T> StringConverter<T> getStringConverter(Class<T> clazz) { if (CONVERTERS == null) { synchronized (StringConverters.class) { if (CONVERTERS == null) { CONVERTERS = init(); } } } @SuppressWarnings("unchecked") StringConverter<T> converterToUse = (StringConverter<T>) CONVERTERS.get(clazz); return converterToUse; } private static ConcurrentMap<Class<?>, StringConverter<?>> init() { ConcurrentMap<Class<?>, StringConverter<?>> map = new MapMaker().makeMap(); map.putAll(ImmutableMap.<Class<?>, StringConverter<?>>builder() .put(Optional.absent().getClass(), new OptionalConverter()) .put(Optional.of(true).getClass(), new OptionalConverter()) .put(Cookie.class, new CookieStringConverter()).put(EntityTag.class, new EntityTagDelegate()) .put(Locale.class, new LocaleDelegate()).put(MediaType.class, new MediaTypeStringConverter()) .put(URI.class, new UriStringConverter()).put(NewCookie.class, new NewCookieStringConverter()) .put(CacheControl.class, new CacheControlDelegate()).build()); return map; } private static abstract class OneWayStringConverter<T> implements StringConverter<T> { @Override public T fromString(String string) { throw new UnsupportedOperationException(); } } public static class OptionalConverter extends OneWayStringConverter<Optional<?>> { @Override public String toString(Optional<?> value) { if (value.isPresent()) { return value.get().toString(); } return null; } } public static class CookieStringConverter extends OneWayStringConverter<Cookie> { public String toString(Cookie cookie) { StringBuffer buf = new StringBuffer(); ServerCookie.appendCookieValue(buf, 0, cookie.getName(), cookie.getValue(), cookie.getPath(), cookie.getDomain(), null, -1, false); return buf.toString(); } } public static class EntityTagDelegate extends OneWayStringConverter<EntityTag> { public String toString(EntityTag value) { String weak = value.isWeak() ? "W/" : ""; return weak + value.getValue(); } } public static class LocaleDelegate extends OneWayStringConverter<Locale> { public String toString(Locale value) { return toLanguageString(value); } /** * HTTP 1.1 has different String format for language than what java.util.Locale does '-' instead of '_' * as a separator * * @param value * @return */ private String toLanguageString(Locale value) { StringBuffer buf = new StringBuffer(value.getLanguage().toLowerCase()); if (value.getCountry() != null && !value.getCountry().equals("")) buf.append("-").append(value.getCountry().toLowerCase()); return buf.toString(); } } public static class MediaTypeStringConverter implements StringConverter<MediaType> { @Override public MediaType fromString(String type) { if (type == null) throw new IllegalArgumentException("MediaType value is null"); return parse(type); } public static MediaType parse(String type) { String params = null; int idx = type.indexOf(";"); if (idx > -1) { params = type.substring(idx + 1).trim(); type = type.substring(0, idx); } String major = null; String subtype = null; String[] paths = type.split("/"); if (paths.length < 2 && type.equals("*")) { major = "*"; subtype = "*"; } else if (paths.length != 2) { throw new IllegalArgumentException("Failure parsing MediaType string: " + type); } else if (paths.length == 2) { major = paths[0]; subtype = paths[1]; } if (params != null && !params.equals("")) { HashMap<String, String> typeParams = new HashMap<String, String>(); int start = 0; while (start < params.length()) { start = setParam(typeParams, params, start); } return new MediaType(major, subtype, typeParams); } else { return new MediaType(major, subtype); } } static int getEndName(String params, int start) { int equals = params.indexOf('=', start); int semicolon = params.indexOf(';', start); if (equals == -1 && semicolon == -1) return params.length(); if (equals == -1) return semicolon; if (semicolon == -1) return equals; int end = (equals < semicolon) ? equals : semicolon; return end; } public static int setParam(HashMap<String, String> typeParams, String params, int start) { boolean quote = false; boolean backslash = false; int end = getEndName(params, start); String name = params.substring(start, end).trim(); if (end < params.length() && params.charAt(end) == '=') end++; StringBuilder buffer = new StringBuilder(params.length() - end); int i = end; for (; i < params.length(); i++) { char c = params.charAt(i); switch (c) { case '"': { if (backslash) { backslash = false; buffer.append(c); } else { quote = !quote; } break; } case '\\': { if (backslash) { backslash = false; buffer.append(c); } break; } case ';': { if (!quote) { String value = buffer.toString().trim(); typeParams.put(name, value); return i + 1; } else { buffer.append(c); } break; } default: { buffer.append(c); break; } } } String value = buffer.toString().trim(); typeParams.put(name, value); return i; } public String toString(MediaType type) { String rtn = type.getType().toLowerCase() + "/" + type.getSubtype().toLowerCase(); if (type.getParameters() == null || type.getParameters().size() == 0) return rtn; for (String name : type.getParameters().keySet()) { String val = type.getParameters().get(name); rtn += ";" + name + "=\"" + val + "\""; } return rtn; } } public static class UriStringConverter extends OneWayStringConverter<URI> { public String toString(URI uri) { return uri.toASCIIString(); } } public static class NewCookieStringConverter extends OneWayStringConverter<NewCookie> { protected void quote(StringBuilder b, String value) { if (value.indexOf(' ') > -1) { b.append('"'); b.append(value); b.append('"'); } else { b.append(value); } } public String toString(NewCookie cookie) { StringBuilder b = new StringBuilder(); b.append(cookie.getName()).append('='); quote(b, cookie.getValue()); b.append(";").append("Version=").append(cookie.getVersion()); if (cookie.getComment() != null) { b.append(";Comment="); quote(b, cookie.getComment()); } if (cookie.getDomain() != null) { b.append(";Domain="); quote(b, cookie.getDomain()); } if (cookie.getPath() != null) { b.append(";Path="); quote(b, cookie.getPath()); } if (cookie.getMaxAge() != -1) { b.append(";Max-Age="); b.append(cookie.getMaxAge()); } if (cookie.isSecure()) b.append(";Secure"); return b.toString(); } } public static class CacheControlDelegate extends OneWayStringConverter<CacheControl> { private StringBuffer addDirective(String directive, StringBuffer buffer) { if (buffer.length() > 0) buffer.append(", "); buffer.append(directive); return buffer; } public String toString(CacheControl value) { StringBuffer buffer = new StringBuffer(); if (value.isNoCache()) { List<String> fields = value.getNoCacheFields(); if (fields.size() < 1) { addDirective("no-cache", buffer); } else { for (String field : value.getNoCacheFields()) { addDirective("no-cache", buffer).append("=\"").append(field).append("\""); } } } if (value.isMustRevalidate()) addDirective("must-revalidate", buffer); if (value.isNoTransform()) addDirective("no-transform", buffer); if (value.isNoStore()) addDirective("no-store", buffer); if (value.isProxyRevalidate()) addDirective("rest-revalidate", buffer); if (value.getSMaxAge() > -1) addDirective("s-maxage", buffer).append("=").append(value.getSMaxAge()); if (value.getMaxAge() > -1) addDirective("max-age", buffer).append("=").append(value.getMaxAge()); if (value.isPrivate()) { List<String> fields = value.getPrivateFields(); if (fields.size() < 1) addDirective("private", buffer); else { for (String field : value.getPrivateFields()) { addDirective("private", buffer).append("=\"").append(field).append("\""); } } } for (String key : value.getCacheExtension().keySet()) { String val = value.getCacheExtension().get(key); addDirective(key, buffer); if (val != null && !"".equals(val)) { buffer.append("=\"").append(val).append("\""); } } return buffer.toString(); } } }