| 1 | /** |
| 2 | * Licensed to jclouds, Inc. (jclouds) under one or more |
| 3 | * contributor license agreements. See the NOTICE file |
| 4 | * distributed with this work for additional information |
| 5 | * regarding copyright ownership. jclouds licenses this file |
| 6 | * to you under the Apache License, Version 2.0 (the |
| 7 | * "License"); you may not use this file except in compliance |
| 8 | * with the License. You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, |
| 13 | * software distributed under the License is distributed on an |
| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| 15 | * KIND, either express or implied. See the License for the |
| 16 | * specific language governing permissions and limitations |
| 17 | * under the License. |
| 18 | */ |
| 19 | package org.jclouds.http.functions; |
| 20 | |
| 21 | import static com.google.common.base.Preconditions.checkArgument; |
| 22 | import static com.google.common.base.Preconditions.checkNotNull; |
| 23 | import static com.google.common.io.Closeables.closeQuietly; |
| 24 | |
| 25 | import java.io.IOException; |
| 26 | import java.io.InputStream; |
| 27 | import java.io.StringReader; |
| 28 | |
| 29 | import javax.inject.Inject; |
| 30 | |
| 31 | import org.jclouds.http.HttpRequest; |
| 32 | import org.jclouds.http.HttpResponse; |
| 33 | import org.jclouds.rest.InvocationContext; |
| 34 | import org.jclouds.rest.internal.GeneratedHttpRequest; |
| 35 | import org.jclouds.util.Strings2; |
| 36 | import org.xml.sax.InputSource; |
| 37 | import org.xml.sax.SAXException; |
| 38 | import org.xml.sax.SAXParseException; |
| 39 | import org.xml.sax.XMLReader; |
| 40 | import org.xml.sax.helpers.DefaultHandler; |
| 41 | |
| 42 | import com.google.common.base.Function; |
| 43 | import com.google.common.base.Throwables; |
| 44 | |
| 45 | /** |
| 46 | * This object will parse the body of an HttpResponse and return the result of type <T> back to the |
| 47 | * caller. |
| 48 | * |
| 49 | * @author Adrian Cole |
| 50 | */ |
| 51 | public class ParseSax<T> implements Function<HttpResponse, T>, InvocationContext<ParseSax<T>> { |
| 52 | |
| 53 | private final XMLReader parser; |
| 54 | private final HandlerWithResult<T> handler; |
| 55 | private HttpRequest request; |
| 56 | |
| 57 | public static interface Factory { |
| 58 | <T> ParseSax<T> create(HandlerWithResult<T> handler); |
| 59 | } |
| 60 | |
| 61 | @Inject |
| 62 | public ParseSax(XMLReader parser, HandlerWithResult<T> handler) { |
| 63 | this.parser = checkNotNull(parser, "parser"); |
| 64 | this.handler = checkNotNull(handler, "handler"); |
| 65 | } |
| 66 | |
| 67 | public T apply(HttpResponse from) { |
| 68 | try { |
| 69 | checkNotNull(from, "http response"); |
| 70 | checkNotNull(from.getPayload(), "payload in " + from); |
| 71 | } catch (NullPointerException e) { |
| 72 | return addDetailsAndPropagate(from, e); |
| 73 | } |
| 74 | if (from.getStatusCode() >= 300) |
| 75 | return convertStreamToStringAndParse(from); |
| 76 | InputStream is = from.getPayload().getInput(); |
| 77 | try { |
| 78 | return parse(new InputSource(is)); |
| 79 | } catch (RuntimeException e) { |
| 80 | return addDetailsAndPropagate(from, e); |
| 81 | } finally { |
| 82 | closeQuietly(is); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | private T convertStreamToStringAndParse(HttpResponse from) { |
| 87 | try { |
| 88 | return parse(Strings2.toStringAndClose(from.getPayload().getInput())); |
| 89 | } catch (Exception e) { |
| 90 | return addDetailsAndPropagate(from, e); |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | public T parse(String from) { |
| 95 | try { |
| 96 | checkNotNull(from, "xml string"); |
| 97 | checkArgument(from.indexOf('<') >= 0, String.format("not an xml document [%s] ", from)); |
| 98 | } catch (RuntimeException e) { |
| 99 | return addDetailsAndPropagate(null, e); |
| 100 | } |
| 101 | return parse(new InputSource(new StringReader(from))); |
| 102 | } |
| 103 | |
| 104 | public T parse(InputStream from) { |
| 105 | try { |
| 106 | return parse(new InputSource(from)); |
| 107 | } finally { |
| 108 | closeQuietly(from); |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | public T parse(InputSource from) { |
| 113 | try { |
| 114 | return doParse(from); |
| 115 | } catch (Exception e) { |
| 116 | return addDetailsAndPropagate(null, e); |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | protected T doParse(InputSource from) throws IOException, SAXException { |
| 121 | checkNotNull(from, "xml inputsource"); |
| 122 | from.setEncoding("UTF-8"); |
| 123 | parser.setContentHandler(getHandler()); |
| 124 | // This method should accept documents with a BOM (Byte-order mark) |
| 125 | parser.parse(from); |
| 126 | return getHandler().getResult(); |
| 127 | } |
| 128 | |
| 129 | public T addDetailsAndPropagate(HttpResponse response, Exception e) { |
| 130 | StringBuilder message = new StringBuilder(); |
| 131 | if (request != null) { |
| 132 | message.append("request: ").append(request.getRequestLine()); |
| 133 | } |
| 134 | if (response != null) { |
| 135 | if (message.length() != 0) |
| 136 | message.append("; "); |
| 137 | message.append("response: ").append(response.getStatusLine()); |
| 138 | } |
| 139 | if (e instanceof SAXParseException) { |
| 140 | SAXParseException parseException = (SAXParseException) e; |
| 141 | String systemId = parseException.getSystemId(); |
| 142 | if (systemId == null) { |
| 143 | systemId = ""; |
| 144 | } |
| 145 | if (message.length() != 0) |
| 146 | message.append("; "); |
| 147 | message.append(String.format("error at %d:%d in document %s", parseException.getColumnNumber(), |
| 148 | parseException.getLineNumber(), systemId)); |
| 149 | } |
| 150 | if (message.length() != 0) { |
| 151 | message.append("; cause: ").append(e.toString()); |
| 152 | throw new RuntimeException(message.toString(), e); |
| 153 | } else { |
| 154 | Throwables.propagate(e); |
| 155 | return null; |
| 156 | } |
| 157 | |
| 158 | } |
| 159 | |
| 160 | public HandlerWithResult<T> getHandler() { |
| 161 | return handler; |
| 162 | } |
| 163 | |
| 164 | /** |
| 165 | * Handler that produces a useable domain object accessible after parsing completes. |
| 166 | * |
| 167 | * @author Adrian Cole |
| 168 | */ |
| 169 | public abstract static class HandlerWithResult<T> extends DefaultHandler implements |
| 170 | InvocationContext<HandlerWithResult<T>> { |
| 171 | private HttpRequest request; |
| 172 | |
| 173 | protected HttpRequest getRequest() { |
| 174 | return request; |
| 175 | } |
| 176 | |
| 177 | public abstract T getResult(); |
| 178 | |
| 179 | @Override |
| 180 | public HandlerWithResult<T> setContext(HttpRequest request) { |
| 181 | this.request = request; |
| 182 | return this; |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | public abstract static class HandlerForGeneratedRequestWithResult<T> extends HandlerWithResult<T> { |
| 187 | @Override |
| 188 | protected GeneratedHttpRequest<?> getRequest() { |
| 189 | return (GeneratedHttpRequest<?>) super.getRequest(); |
| 190 | } |
| 191 | |
| 192 | @Override |
| 193 | public HandlerForGeneratedRequestWithResult<T> setContext(HttpRequest request) { |
| 194 | checkArgument(request instanceof GeneratedHttpRequest<?>, "note this handler requires a GeneratedHttpRequest"); |
| 195 | super.setContext(request); |
| 196 | return this; |
| 197 | } |
| 198 | } |
| 199 | |
| 200 | @Override |
| 201 | public ParseSax<T> setContext(HttpRequest request) { |
| 202 | handler.setContext(request); |
| 203 | this.request = request; |
| 204 | return this; |
| 205 | } |
| 206 | } |