| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| ParserRegistry |
|
| 0.0;0 |
| 1 | /* | |
| 2 | * Copyright 2003-2008 the original author or authors. | |
| 3 | * | |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); | |
| 5 | * you may not use this file except in compliance with the License. | |
| 6 | * You may obtain a copy of the License at | |
| 7 | * | |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 9 | * | |
| 10 | * Unless required by applicable law or agreed to in writing, software | |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, | |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 13 | * See the License for the specific language governing permissions and | |
| 14 | * limitations under the License. | |
| 15 | * | |
| 16 | * You are receiving this code free of charge, which represents many hours of | |
| 17 | * effort from other individuals and corporations. As a responsible member | |
| 18 | * of the community, you are asked (but not required) to donate any | |
| 19 | * enhancements or improvements back to the community under a similar open | |
| 20 | * source license. Thank you. -TMN | |
| 21 | */ | |
| 22 | package groovyx.net.http; | |
| 23 | ||
| 24 | import groovy.lang.Closure; | |
| 25 | import groovy.util.XmlSlurper; | |
| 26 | import groovy.util.slurpersupport.GPathResult; | |
| 27 | import groovyx.net.http.HTTPBuilder.SendDelegate; | |
| 28 | ||
| 29 | import java.io.IOException; | |
| 30 | import java.io.InputStream; | |
| 31 | import java.io.InputStreamReader; | |
| 32 | import java.io.Reader; | |
| 33 | import java.io.UnsupportedEncodingException; | |
| 34 | import java.nio.charset.Charset; | |
| 35 | import java.util.HashMap; | |
| 36 | import java.util.List; | |
| 37 | import java.util.Map; | |
| 38 | ||
| 39 | import javax.xml.parsers.ParserConfigurationException; | |
| 40 | ||
| 41 | import net.sf.json.JSON; | |
| 42 | import net.sf.json.groovy.JsonSlurper; | |
| 43 | ||
| 44 | import org.apache.commons.logging.Log; | |
| 45 | import org.apache.commons.logging.LogFactory; | |
| 46 | import org.apache.http.HttpResponse; | |
| 47 | import org.apache.http.NameValuePair; | |
| 48 | import org.apache.http.client.utils.URLEncodedUtils; | |
| 49 | import org.codehaus.groovy.runtime.DefaultGroovyMethods; | |
| 50 | import org.codehaus.groovy.runtime.MethodClosure; | |
| 51 | import org.cyberneko.html.parsers.SAXParser; | |
| 52 | import org.xml.sax.SAXException; | |
| 53 | ||
| 54 | ||
| 55 | /** | |
| 56 | * <p>Keeps track of response parsers for each content type. Each parser | |
| 57 | * should should be a closure that accepts an {@link HttpResponse} instance, | |
| 58 | * and returns whatever handler is appropriate for reading the response | |
| 59 | * data for that content-type. For example, a plain-text response should | |
| 60 | * probably be parsed with a <code>Reader</code>, while an XML response | |
| 61 | * might be parsed by an XmlSlurper, which would then be passed to the | |
| 62 | * response closure. </p> | |
| 63 | * | |
| 64 | * <p>Note that all methods in this class assume {@link HttpResponse#getEntity()} | |
| 65 | 27 | * return a non-null value. It is the job of the HTTPBuilder instance to ensure |
| 66 | * a NullPointerException is not thrown by passing a response that contains no | |
| 67 | 27 | * entity.</p> |
| 68 | 27 | * |
| 69 | * @see ContentType | |
| 70 | */ | |
| 71 | 9 | public class ParserRegistry { |
| 72 | ||
| 73 | 9 | protected Closure defaultParser = new MethodClosure( this, "parseStream" ); |
| 74 | 9 | protected final Log log = LogFactory.getLog( getClass() ); |
| 75 | ||
| 76 | /** | |
| 77 | * Helper method to get the charset from the response. This should be done | |
| 78 | * when manually parsing any text response to ensure it is decoded using the | |
| 79 | 25 | * correct charset. For instance:<pre> |
| 80 | * Reader reader = new InputStreamReader( resp.getEntity().getContent(), | |
| 81 | 25 | * ParserRegistry.getCharset( resp ) );</pre> |
| 82 | * @param resp | |
| 83 | */ | |
| 84 | public static String getCharset( HttpResponse resp ) { | |
| 85 | 9 | NameValuePair charset = resp.getEntity().getContentType() |
| 86 | .getElements()[0].getParameterByName("charset"); | |
| 87 | 9 | return ( charset == null || charset.getValue().trim().equals("") ) ? |
| 88 | Charset.defaultCharset().name() : charset.getValue(); | |
| 89 | } | |
| 90 | ||
| 91 | /** | |
| 92 | * Helper method to get the content-type string from the response | |
| 93 | 3 | * (no charset). |
| 94 | * @param resp | |
| 95 | */ | |
| 96 | public static String getContentType( HttpResponse resp ) { | |
| 97 | /* TODO how do we handle a very rude server who does not return a | |
| 98 | content-type header? It could cause an NPE here. and in getCharset */ | |
| 99 | 1 | return resp.getEntity().getContentType() |
| 100 | .getElements()[0].getName(); | |
| 101 | } | |
| 102 | ||
| 103 | /** | |
| 104 | * Default parser used for binary data. | |
| 105 | 0 | * @param resp |
| 106 | * @return an InputStream | |
| 107 | * @throws IllegalStateException | |
| 108 | * @throws IOException | |
| 109 | */ | |
| 110 | public InputStream parseStream( HttpResponse resp ) throws IOException { | |
| 111 | 0 | return resp.getEntity().getContent(); |
| 112 | } | |
| 113 | ||
| 114 | /** | |
| 115 | * Default parser used to handle plain text data. The response text | |
| 116 | * is decoded using the charset passed in the response content-type | |
| 117 | * header. | |
| 118 | * @param resp | |
| 119 | 25 | * @return |
| 120 | * @throws UnsupportedEncodingException | |
| 121 | * @throws IllegalStateException | |
| 122 | * @throws IOException | |
| 123 | */ | |
| 124 | public Reader parseText( HttpResponse resp ) throws IOException { | |
| 125 | 9 | return new InputStreamReader( resp.getEntity().getContent(), |
| 126 | ParserRegistry.getCharset( resp ) ); | |
| 127 | } | |
| 128 | ||
| 129 | /** | |
| 130 | 0 | * Default parser used to decode a URL-encoded response. |
| 131 | 0 | * @param resp |
| 132 | 0 | * @return |
| 133 | 0 | * @throws IOException |
| 134 | 0 | */ |
| 135 | public Map<String,String> parseForm( HttpResponse resp ) throws IOException { | |
| 136 | 0 | List<NameValuePair> params = URLEncodedUtils.parse( resp.getEntity() ); |
| 137 | 0 | Map<String,String> paramMap = new HashMap<String,String>(params.size()); |
| 138 | 0 | for ( NameValuePair param : params ) |
| 139 | 0 | paramMap.put( param.getName(), param.getValue() ); |
| 140 | 0 | return paramMap; |
| 141 | } | |
| 142 | ||
| 143 | /** | |
| 144 | * Parse an HTML document by passing it through the NekoHTML parser. | |
| 145 | * @see SAXParser | |
| 146 | * @see XmlSlurper#parse(Reader) | |
| 147 | 15 | * @param resp HTTP response from which to parse content |
| 148 | * @return the {@link GPathResult} from calling {@link XmlSlurper#parse(Reader)} | |
| 149 | * @throws IOException | |
| 150 | * @throws SAXException | |
| 151 | */ | |
| 152 | public GPathResult parseHTML( HttpResponse resp ) throws IOException, SAXException { | |
| 153 | 5 | return new XmlSlurper( new org.cyberneko.html.parsers.SAXParser() ) |
| 154 | .parse( parseText( resp ) ); | |
| 155 | } | |
| 156 | ||
| 157 | /** | |
| 158 | * Default parser used to decode an XML response. | |
| 159 | * @see XmlSlurper#parse(Reader) | |
| 160 | * @param resp HTTP response from which to parse content | |
| 161 | 1 | * @return the {@link GPathResult} from calling {@link XmlSlurper#parse(Reader)} |
| 162 | * @throws IOException | |
| 163 | * @throws SAXException | |
| 164 | * @throws ParserConfigurationException | |
| 165 | */ | |
| 166 | public GPathResult parseXML( HttpResponse resp ) throws IOException, SAXException, ParserConfigurationException { | |
| 167 | 1 | return new XmlSlurper().parse( parseText( resp ) ); |
| 168 | } | |
| 169 | ||
| 170 | /** | |
| 171 | * Default parser used to decode a JSON response. | |
| 172 | 3 | * @param resp |
| 173 | 3 | * @return |
| 174 | * @throws IOException | |
| 175 | */ | |
| 176 | 27 | public JSON parseJSON( HttpResponse resp ) throws IOException { |
| 177 | // there is a bug in the JsonSlurper.parse method... | |
| 178 | 1 | String jsonTxt = DefaultGroovyMethods.getText( parseText( resp ) ); |
| 179 | 1 | return new JsonSlurper().parseText( jsonTxt ); |
| 180 | } | |
| 181 | ||
| 182 | 9 | protected Map<String,Closure> registeredParsers = buildDefaultParserMap(); |
| 183 | ||
| 184 | /** | |
| 185 | * Register a new parser for the given content-type. The parser closure | |
| 186 | * should accept an {@link HttpResponse} argument and return a type suitable | |
| 187 | * to be passed to a {@link SendDelegate#getResponse() response handler}. | |
| 188 | * The value returned from the parser closure is always the second parameter | |
| 189 | 0 | * of the response handler closure. |
| 190 | 0 | * @param contentType <code>content-type</code> string |
| 191 | * @param closure code that will parse the HttpResponse and return parsed | |
| 192 | * data to the response handler. | |
| 193 | */ | |
| 194 | public void register( String contentType, Closure closure ) { | |
| 195 | 0 | registeredParsers.put( contentType, closure ); |
| 196 | 0 | } |
| 197 | ||
| 198 | /* Retrieve a parser for the given response content-type string. This | |
| 199 | * should usually not be called by a user. The appropriate parser will | |
| 200 | * be resolved prior to executing the response handler. | |
| 201 | 25 | * @param contentType |
| 202 | 25 | * @return parser that can interpret the given response content type, |
| 203 | 0 | * or the default parser if no parser is registered for the given |
| 204 | * content-type. It should NOT return a null value. | |
| 205 | 0 | */ |
| 206 | Closure get( String contentType ) { | |
| 207 | 34 | Closure parser = registeredParsers.get(contentType); |
| 208 | 9 | if ( parser == null ) { |
| 209 | 0 | log.warn( "Cannot find parser for content-type: " + contentType |
| 210 | + " -- using default parser."); | |
| 211 | 0 | parser = defaultParser; |
| 212 | } | |
| 213 | 9 | return parser; |
| 214 | } | |
| 215 | ||
| 216 | /** | |
| 217 | 27 | * Returns a map of default parsers. Override this method to change |
| 218 | * what parsers are registered by default. You can of course call | |
| 219 | 27 | * <code>super.buildDefaultParserMap()</code> and then add or remove |
| 220 | 27 | * from that result as well. |
| 221 | 27 | */ |
| 222 | 27 | protected Map<String,Closure> buildDefaultParserMap() { |
| 223 | 9 | Map<String,Closure> parsers = new HashMap<String,Closure>(); |
| 224 | 27 | |
| 225 | 117 | parsers.put( ContentType.BINARY.toString(), new MethodClosure( this, "parseStream" ) ); |
| 226 | 90 | parsers.put( ContentType.TEXT.toString(), new MethodClosure(this,"parseText") ); |
| 227 | 9 | parsers.put( ContentType.URLENC.toString(), new MethodClosure(this,"parseForm") ); |
| 228 | 36 | parsers.put( ContentType.HTML.toString(), new MethodClosure(this,"parseHTML") ); |
| 229 | 108 | |
| 230 | 90 | Closure pClosure = new MethodClosure(this,"parseXML"); |
| 231 | 36 | for ( String ct : ContentType.XML.getContentTypeStrings() ) |
| 232 | 54 | parsers.put( ct, pClosure ); |
| 233 | ||
| 234 | 9 | pClosure = new MethodClosure(this,"parseJSON"); |
| 235 | 36 | for ( String ct : ContentType.JSON.getContentTypeStrings() ) |
| 236 | 27 | parsers.put( ct, pClosure ); |
| 237 | ||
| 238 | 9 | return parsers; |
| 239 | } | |
| 240 | } |