#1638 Add Parameter Object pattern (#1650)

* #1638 Add Parameter Object pattern

* #1638 Fix comments and formatting for Parameter Object pattern

* #1638 Fix formatting, commenting, remove string concatenation in Parameter Object pattern

* #1638 Fix readme formatting and log parameter object

parameter-object/src/main/java/com/iluwatar/parameter/object/SearchService.java

@@ -0,0 +1,60 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.parameter.object;
+
+public class SearchService {
+
+  /**
+   * Below two methods of name `search` is overloaded so that we can send a default value for
+   * one of the criteria and call the final api. A default SortOrder is sent in the first method
+   * and a default SortBy is sent in the second method. So two separate method definitions are
+   * needed for having default values for one argument in each case. Hence multiple overloaded
+   * methods are needed as the number of argument increases.
+   */
+  public String search(String type, String sortBy) {
+    return getQuerySummary(type, sortBy, SortOrder.ASC);
+  }
+
+  public String search(String type, SortOrder sortOrder) {
+    return getQuerySummary(type, "price", sortOrder);
+  }
+
+
+  /**
+   * The need for multiple method definitions can be avoided by the Parameter Object pattern.
+   * Below is the example where only one method is required and all the logic for having default
+   * values are abstracted into the Parameter Object at the time of object creation.
+   */
+  public String search(ParameterObject parameterObject) {
+    return getQuerySummary(parameterObject.getType(), parameterObject.getSortBy(),
+        parameterObject.getSortOrder());
+  }
+
+  private String getQuerySummary(String type, String sortBy, SortOrder sortOrder) {
+    return String.format("Requesting shoes of type \"%s\" sorted by \"%s\" in \"%sending\" order..",
+        type,
+        sortBy,
+        sortOrder.getValue());
+  }
+}