svn commit: r1539991 - /oodt/trunk/grid/src/main/java/org/apache/oodt/grid/RestfulProductQueryServlet.java

[lu...@apache.org]

Author: luca
Date: Fri Nov  8 11:47:11 2013
New Revision: 1539991

URL: http://svn.apache.org/r1539991
Log:
Adding a subclass of QueryServlet that can be used to construct XMLQueries from non DIS-style syntax (OODT-656)

Added:
    oodt/trunk/grid/src/main/java/org/apache/oodt/grid/RestfulProductQueryServlet.java   (with props)

Added: oodt/trunk/grid/src/main/java/org/apache/oodt/grid/RestfulProductQueryServlet.java
URL: http://svn.apache.org/viewvc/oodt/trunk/grid/src/main/java/org/apache/oodt/grid/RestfulProductQueryServlet.java?rev=1539991&view=auto
==============================================================================
--- oodt/trunk/grid/src/main/java/org/apache/oodt/grid/RestfulProductQueryServlet.java (added)
+++ oodt/trunk/grid/src/main/java/org/apache/oodt/grid/RestfulProductQueryServlet.java Fri Nov  8 11:47:11 2013
@@ -0,0 +1,87 @@
+/**
+ * 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 org.apache.oodt.grid;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Enumeration;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.apache.oodt.xmlquery.XMLQuery;
+
+/**
+ * The {@link RestfulProductQueryServlet} is an alternative to the standard {@link ProductQueryServlet} 
+ * that allows clients to use a more intuitive syntax for encoding query constraints, than the traditional
+ * DIS-style syntax. 
+ * For example, instead of encoding a request as: 
+ * "?q=identifier+EQ+urn:nasa:pds:phx_lidar:reduced:LS075RLS_00902835894_1885M1+AND+package+EQ+TGZ"
+ * a client could encode it as:
+ * "?identifier=urn:nasa:pds:phx_lidar:reduced:LS075RLS_00902835894_1885M1&package=TGZ".
+ * Note that this servlet is meant to be back-ward compatible, i.e. it will first process a request by
+ * parsing the "xmlq=" and "q=" parameters. If those are not found, it will build a request by combining 
+ * all the available HTTP parameters in logical AND.
+ * Note also that this servlet is NOT enabled by default 
+ * (i.e. it must be explicitly configured by changing the web-grid deployment descriptor web.xml).
+ * 
+ * @author Luca Cinquini
+ *
+ */
+public class RestfulProductQueryServlet extends ProductQueryServlet {
+	
+	private static final long serialVersionUID = 1L;
+
+	/**
+	 * Overridden implementation that defaults to the standard behavior if the parameters "q" or "xmlq" are found,
+	 * otherwise it uses the available request parameters to build a constraint query with logical AND.
+	 */
+	@Override
+	protected XMLQuery getQuery(HttpServletRequest req, HttpServletResponse res) throws IOException {
+		
+		// if DIS-style parameters are found, default to standard processing
+		if (req.getParameter("xmlq") !=null || req.getParameter("q")!=null) {
+			XMLQuery xmlQuery = super.getQuery(req, res);
+			return xmlQuery;
+			
+		// combine all HTTP (name, value) pairs into XML query string with logical AND
+		} else {
+			
+			StringBuffer q = new StringBuffer("");
+			Enumeration<String> parameterNames = req.getParameterNames();
+			while (parameterNames.hasMoreElements()) {
+				String paramName = parameterNames.nextElement();
+				String[] paramValues = req.getParameterValues(paramName);
+				for (int i = 0; i < paramValues.length; i++) {
+					if (q.length()>0) q.append(" AND ");
+					q.append(paramName+" EQ "+paramValues[i]);
+				}
+			}
+			
+			// build XMLQuery object from HTTP parameters
+			// no need to URL-encode since this request doesn't go over the network
+			System.out.println("Executing query="+q.toString());
+			return new XMLQuery(q.toString(), "wgq", "Web Grid Query",	
+					"Query from Web-Grid", /*ddID*/null,                   
+					/*resultModeId*/null, /*propType*/null,                
+					/*propLevels*/null, /*maxResults*/Integer.MAX_VALUE,   
+					new ArrayList<String>(), true);			
+		}
+		
+	}
+
+}

Propchange: oodt/trunk/grid/src/main/java/org/apache/oodt/grid/RestfulProductQueryServlet.java
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