Mercurial > dive4elements > river

comparison gwt-client/src/main/java/org/dive4elements/river/client/server/WQInfoServiceImpl.java @ 5838:5aa05a7a34b7

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Rename modules to more fitting names.
author Sascha L. Teichmann <teichmann@intevation.de>
date Thu, 25 Apr 2013 15:23:37 +0200
parents flys-client/src/main/java/org/dive4elements/river/client/server/WQInfoServiceImpl.java@821a02bbfb4e
children 172338b1407f
comparison
equal deleted inserted replaced
5837:d9901a08d0a6 5838:5aa05a7a34b7
1 package org.dive4elements.river.client.server;
2
3 import java.util.ArrayList;
4 import java.util.Arrays;
5 import java.util.Comparator;
6 import java.util.List;
7
8 import javax.xml.xpath.XPathConstants;
9
10 import org.w3c.dom.Document;
11 import org.w3c.dom.Element;
12 import org.w3c.dom.Node;
13 import org.w3c.dom.NodeList;
14
15 import org.apache.log4j.Logger;
16
17 import com.google.gwt.user.server.rpc.RemoteServiceServlet;
18
19 import org.dive4elements.artifacts.common.ArtifactNamespaceContext;
20 import org.dive4elements.artifacts.common.utils.XMLUtils;
21
22 import org.dive4elements.artifacts.httpclient.exceptions.ConnectionException;
23 import org.dive4elements.artifacts.httpclient.http.HttpClient;
24 import org.dive4elements.artifacts.httpclient.http.HttpClientImpl;
25
26 import org.dive4elements.river.client.shared.exceptions.ServerException;
27 import org.dive4elements.river.client.client.services.WQInfoService;
28 import org.dive4elements.river.client.shared.model.WQInfoObject;
29 import org.dive4elements.river.client.shared.model.WQInfoObjectImpl;
30
31
32 /**
33 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
34 */
35 public class WQInfoServiceImpl
36 extends RemoteServiceServlet
37 implements WQInfoService
38 {
39 private static final Logger logger =
40 Logger.getLogger(WQInfoServiceImpl.class);
41
42 public static final String ERROR_NO_WQINFO_FOUND =
43 "error_no_wqinfo_found";
44
45 public static final String XPATH_WQS = "art:service/art:mainvalues/art:mainvalue";
46
47
48 public WQInfoObject[] getWQInfo(
49 String locale,
50 String river,
51 double from,
52 double to)
53 throws ServerException
54 {
55 logger.info("WQInfoServiceImpl.getWQInfo");
56
57 String url = getServletContext().getInitParameter("server-url");
58
59 Document doc = XMLUtils.newDocument();
60
61 XMLUtils.ElementCreator ec = new XMLUtils.ElementCreator(
62 doc,
63 ArtifactNamespaceContext.NAMESPACE_URI,
64 ArtifactNamespaceContext.NAMESPACE_PREFIX);
65
66 Element mainvalues = ec.create("mainvalues");
67 Element riverEl = ec.create("river");
68 Element startEl = ec.create("start");
69 Element endEl = ec.create("end");
70
71 riverEl.setTextContent(river);
72 startEl.setTextContent(Double.valueOf(from).toString());
73 endEl.setTextContent(Double.valueOf(to).toString());
74
75 mainvalues.appendChild(riverEl);
76 mainvalues.appendChild(startEl);
77 mainvalues.appendChild(endEl);
78
79 doc.appendChild(mainvalues);
80
81 HttpClient client = new HttpClientImpl(url, locale);
82
83 try {
84 Document result = client.callService(url, "mainvalues", doc);
85
86 logger.debug("Extract wq info objects now.");
87 WQInfoObject[] objects = extractWQInfoObjects(result);
88
89 if (objects.length > 0) {
90 return objects;
91 }
92 }
93 catch (ConnectionException ce) {
94 logger.error(ce, ce);
95 }
96
97 throw new ServerException(ERROR_NO_WQINFO_FOUND);
98 }
99
100
101 /**
102 * Extracts all wq info objects from <i>result</i> document.
103 *
104 * @param result The document retrieved by the server.
105 *
106 * @return a list of WQInfoObjects.
107 */
108 protected WQInfoObject[] extractWQInfoObjects(Document result)
109 throws ServerException
110 {
111 NodeList list = (NodeList) XMLUtils.xpath(
112 result,
113 XPATH_WQS,
114 XPathConstants.NODESET,
115 ArtifactNamespaceContext.INSTANCE);
116
117 if (list == null || list.getLength() == 0) {
118 logger.warn("No wq info found.");
119
120 throw new ServerException(ERROR_NO_WQINFO_FOUND);
121 }
122
123 boolean debug = logger.isDebugEnabled();
124
125 int num = list.getLength();
126 if (debug) {
127 logger.debug("Response contains " + num + " objects.");
128 }
129
130 List<WQInfoObject> objects =
131 new ArrayList<WQInfoObject>(num);
132
133 for (int i = 0; i < num; i++) {
134 WQInfoObject obj = buildWQInfoObject(list.item(i));
135
136 if (obj != null) {
137 objects.add(obj);
138 }
139 }
140
141 if (debug) {
142 logger.debug("Retrieved " + objects.size() + " wq values");
143 }
144
145 WQInfoObject [] array = (WQInfoObject[])
146 objects.toArray(new WQInfoObject[objects.size()]);
147
148 Arrays.sort(array, WQ_INFO_OBJECT_CMP);
149
150 return array;
151 }
152
153 public static final Comparator<WQInfoObject> WQ_INFO_OBJECT_CMP =
154 new Comparator<WQInfoObject>() {
155 @Override
156 public int compare(WQInfoObject a, WQInfoObject b) {
157
158 // Descending by type: Qs before Ds
159 int cmp = a.getType().compareTo(b.getType());
160 if (cmp < 0) return +1;
161 if (cmp > 0) return -1;
162
163 // Ascending by value
164 double diff = a.getValue() - b.getValue();
165 if (diff < 0d) return -1;
166 if (diff > 0d) return +1;
167 return 0;
168 }
169 };
170
171 /**
172 * Extracts information for a single wq info object and intializes an
173 * WQInfoObject with them.
174 *
175 * @param node The node that contains the information.
176 *
177 * @return a valid WQInfoObject.
178 */
179 protected static WQInfoObject buildWQInfoObject(Node node) {
180
181 String name = XMLUtils.xpathString(
182 node, "@name", ArtifactNamespaceContext.INSTANCE);
183
184 String type = XMLUtils.xpathString(
185 node, "@type", ArtifactNamespaceContext.INSTANCE);
186
187 String value = XMLUtils.xpathString(
188 node, "@value", ArtifactNamespaceContext.INSTANCE);
189
190 if (name != null && type != null) {
191 try {
192 return new WQInfoObjectImpl(
193 name,
194 type,
195 new Double(value));
196 }
197 catch (NumberFormatException nfe) {
198 logger.warn(nfe.getLocalizedMessage());
199 }
200 }
201
202 logger.warn("Invalid wq info object found.");
203
204 return null;
205 }
206 }
207 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
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