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gdata/java/sample/contacts/ElementParser.java

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+/* Copyright (c) 2008 Google 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 sample.contacts;
+
+import java.util.EnumMap;
+import java.util.Map;
+
+/**
+ * Parser to tokenize element descriptions.
+ * The general format of an element specification looks like:
+ * [<value>]|[<name_1>:<value_1>][,<name_2>:<value_2>]...[,<name_n>:<value_n>]
+ * 
+ * For convenience a single unnamed value can be specified. It is treated as 
+ * "value:<value>", and the parsed value can be accessed with the VALUE key.
+ *
+ * 
+ */
+class ElementParser {
+
+  // Map of parsed property names and values.
+  private Map<PropertyName, String> propertyMap;
+    
+  /**
+   * Constructor.
+   * Parses the element description, and fills the propertyMap.
+   * 
+   * @param elementDesc the element description.
+   * @throws IllegalArgumentException on badly formated element description.
+   */
+  ElementParser(String elementDesc) throws IllegalArgumentException {
+    propertyMap = new EnumMap<PropertyName, String>(PropertyName.class);
+    for (String propertyDesc : elementDesc.split(",")) {
+      String nameValuePair[] = propertyDesc.split(":", 2);
+      if (nameValuePair.length == 1) {
+        propertyMap.put(PropertyName.VALUE, propertyDesc);
+      } else if (nameValuePair.length == 2){
+        propertyMap.put(
+            PropertyName.valueOf(nameValuePair[0].toUpperCase()), 
+            nameValuePair[1]);
+      } else {
+        throw new IllegalArgumentException("Badly formated property:" 
+            + propertyDesc);
+      }
+    }
+  }
+  
+  /**
+   * Checks if the given property has a parsed in value.
+   * 
+   * @param property the property.
+   * @return {@code true} if the given property has a parsed in value,
+   *         otherwise {@code false} 
+   */
+  boolean has(PropertyName property) {
+    return propertyMap.containsKey(property);
+  }
+  
+  /**
+   * Retrieves the parsed in value for the given property.
+   * 
+   * @param property the property.
+   * @return the parsed in value for the given property, or {@code null} if
+   *         the given property was not specified in the element description 
+   *         string.
+   */
+  String get(PropertyName property) {
+    return propertyMap.get(property);
+  }
+  
+  /**
+   * Convenience method to check the value of a boolean property.
+   * 
+   * @param property the property.
+   * @return {@code true} if the parsed in value of the given property is "true"
+   *         {@code false} in any other cases.
+   */
+  boolean is(PropertyName property) {
+    String value = propertyMap.get(property);
+    return (value != null) && (value.toLowerCase().equals("true"));
+  }
+}
+