throws exception with invalid input

samples/bmi/calculator/src/main/java/io/servicecomb/samples/bmi/calculator/CalculatorApplication.java → samples/bmi/calculator/src/main/java/io/servicecomb/samples/bmi/CalculatorApplication.java

@@ -14,7 +14,7 @@
  *  limitations under the License.
  */
 
-package io.servicecomb.samples.bmi.calculator;
+package io.servicecomb.samples.bmi;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;

samples/bmi/calculator/src/main/java/io/servicecomb/samples/bmi/CalculatorEndpoint.java

@@ -0,0 +1,28 @@
+/*
+ *  Copyright 2017 Huawei Technologies Co., Ltd
+ *
+ *  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 io.servicecomb.samples.bmi;
+
+/**
+ * {@link CalculatorEndpoint} provides the common interface for different endpoint implementations.
+ * It needs to be declared as public.
+ */
+public interface CalculatorEndpoint {
+  /**
+   * Calculate the BMI(Body Mass Index).
+   */
+  double calculate(double height, double weight);
+}

samples/bmi/calculator/src/main/java/io/servicecomb/samples/bmi/calculator/CalculatorRestEndpoint.java → samples/bmi/calculator/src/main/java/io/servicecomb/samples/bmi/CalculatorRestEndpoint.java

@@ -14,7 +14,7 @@
  *  limitations under the License.
  */
 
-package io.servicecomb.samples.bmi.calculator;
+package io.servicecomb.samples.bmi;
 
 
 import org.springframework.beans.factory.annotation.Autowired;

samples/bmi/calculator/src/main/java/io/servicecomb/samples/bmi/calculator/CalculatorService.java → samples/bmi/calculator/src/main/java/io/servicecomb/samples/bmi/CalculatorService.java

@@ -14,7 +14,7 @@
  *  limitations under the License.
  */
 
-package io.servicecomb.samples.bmi.calculator;
+package io.servicecomb.samples.bmi;
 
 /**
  * {@link CalculatorService} provides interface of actual BMI calculation.

samples/bmi/calculator/src/main/java/io/servicecomb/samples/bmi/calculator/CalculatorServiceImpl.java → samples/bmi/calculator/src/main/java/io/servicecomb/samples/bmi/CalculatorServiceImpl.java

@@ -14,7 +14,7 @@
  *  limitations under the License.
  */
 
-package io.servicecomb.samples.bmi.calculator;
+package io.servicecomb.samples.bmi;
 
 import java.math.BigDecimal;
 import java.math.RoundingMode;
@@ -29,15 +29,15 @@ public class CalculatorServiceImpl implements CalculatorService {
    */
   @Override
   public double calculate(double height, double weight) {
+    if (height <= 0 || weight <= 0) {
+      throw new IllegalArgumentException("Arguments must be above 0");
+    }
     double heightInMeter = height / 100;
     double bmi = weight / (heightInMeter * heightInMeter);
     return roundToOnePrecision(bmi);
   }
 
   private double roundToOnePrecision(double value) {
-    if (Double.isInfinite(value) || Double.isNaN(value)) {
-      return value;
-    }
     return new BigDecimal(value).setScale(1, RoundingMode.HALF_UP).doubleValue();
   }
 }

samples/bmi/webapp/src/main/java/io/servicecomb/samples/bmi/webapp/GatewayApplication.java → samples/bmi/webapp/src/main/java/io/servicecomb/samples/bmi/GatewayApplication.java

@@ -14,7 +14,7 @@
  *  limitations under the License.
  */
 
-package io.servicecomb.samples.bmi.webapp;
+package io.servicecomb.samples.bmi;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;

samples/bmi/webapp/src/main/resources/static/index.html

@@ -49,44 +49,46 @@ <h3>Your BMI result is: <span id="bmi_result"></span></h3>
         <div class="alert alert-secondary" role="alert">
           <b>Note: </b>Range of healthy weight is between <b>18.5</b> and <b>24.9</b>.
         </div>
+        <div id="error" class="alert alert-danger" role="alert"><p id="error_message"></p></div>
       </div>
     </div>
 
-  </body>
-  <script>
+    <script>
+      $("#error").hide();
       $("#submit").click(function () {
         if ( !$("#height").val() || !$("#weight").val() ) {
           alert("Please input both the height and weight");
           return;
         }
-        if ( $("#height").val() <= 0 ) {
-          alert("Please input a value greater than 0");
-          $("#height").val('');
-          return;
-        }
-        if ( $("#weight").val() <= 0 ) {
-          alert("Please input a value greater than 0");
-          $("#weight").val('');
-          return;
-        }
-        var jqxhr = $.get("/calculator/bmi?height=" + $("#height").val() + "&weight=" + $("#weight").val());
-        jqxhr.done(function (data) {
-          $("#bmi_result").text(data);
-          if ( data < 18.5 || (data < 30 && data >= 25) ) {
-            $("#bmi").removeClass();
-            $("#bmi").addClass("alert");
-            $("#bmi").addClass("alert-warning");
-          } else if ( data < 25 && data >= 18.5 ) {
-            $("#bmi").removeClass();
-            $("#bmi").addClass("alert");
-            $("#bmi").addClass("alert-success");
-          } else {
-            $("#bmi").removeClass();
-            $("#bmi").addClass("alert");
-            $("#bmi").addClass("alert-danger");
+        $.ajax({
+          url: "/calculator/bmi?height=" + $("#height").val() + "&weight=" + $("#weight").val(),
+          type: "GET",
+          success: function (data) {
+            $("#error").hide();
+            $("#bmi_result").text(data);
+            if ( data < 18.5 || (data < 30 && data >= 25) ) {
+              $("#bmi").removeClass().addClass("alert").addClass("alert-warning");
+            } else if ( data < 25 && data >= 18.5 ) {
+              $("#bmi").removeClass().addClass("alert").addClass("alert-success");
+            } else {
+              $("#bmi").removeClass().addClass("alert").addClass("alert-danger");
+            }
+          },
+          error: function (xhr) {
+            $("#bmi").removeClass().addClass("alert").addClass("alert-light");
+            $("#bmi_result").text('');
+            if (xhr.responseText.length == 0) {
+              $("#error_message").text("empty fallback called");
+              $("#error").removeClass().addClass("alert").addClass("alert-success").show();
+              return;
+            }
+            var resp = JSON.parse(xhr.responseText);
+            $("#error_message").text(resp.error + ": " + resp.exception)
+            $("#error").removeClass().addClass("alert").addClass("alert-danger").show();
           }
         });
       });
     </script>
+  </body>
 
 </html>