Changes for BAEL-2176 (#5305)

* Evaluation Article - Spring web-flux

* Evaluation Article - Spring web-flux

* Evaluation Article - Spring web-flux

* Evaluation Article - Spring web-flux

* core-scala: initial commit

* adding core-scala to pom

* Revert "core-scala: initial commit"

This reverts commit d46873405a67addfaa69aa7855b37af9c4a3df14.

* BAEL-2176

* inserting new lines between given, when and then parts

* Formatted using formatter

* indentation changed further

* Suggested changes in coding

gson/src/main/java/org/baeldung/gson/entities/Employee.java

@@ -0,0 +1,36 @@
+package org.baeldung.gson.entities;
+
+public class Employee {
+    private int id;
+    private String name;
+    private String address;
+
+    public Employee(int id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getAddress() {
+        return address;
+    }
+
+    public void setAddress(String address) {
+        this.address = address;
+    }
+}

gson/src/main/java/org/baeldung/gson/serialization/HashMapDeserializer.java

@@ -0,0 +1,66 @@
+package org.baeldung.gson.serialization;
+
+import java.lang.reflect.Type;
+import java.math.BigDecimal;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.baeldung.gson.entities.Employee;
+
+import com.google.gson.*;
+
+public class HashMapDeserializer implements JsonDeserializer<HashMap<String, Object>> {
+
+    @Override
+    public HashMap<String, Object> deserialize(JsonElement elem, Type type, JsonDeserializationContext context) throws JsonParseException {
+        HashMap<String, Object> map = new HashMap<>();
+        for (Map.Entry<String, JsonElement> entry : elem.getAsJsonObject().entrySet()) {
+            JsonElement jsonValue = entry.getValue();
+            Object value = null;
+            if (jsonValue.isJsonPrimitive()) {
+                value = toPrimitive(jsonValue.getAsJsonPrimitive(), context);
+            } else {
+                value = context.deserialize(jsonValue, Employee.class);
+            }
+            map.put(entry.getKey(), value);
+        }
+        return map;
+
+    }
+
+    private Object toPrimitive(JsonPrimitive jsonValue, JsonDeserializationContext context) {
+        if (jsonValue.isBoolean())
+            return jsonValue.getAsBoolean();
+        else if (jsonValue.isString())
+            return jsonValue.getAsString();
+        else {
+            BigDecimal bigDec = jsonValue.getAsBigDecimal();
+            Long l;
+            Integer i;
+            if ((i = toInteger(bigDec)) != null) {
+                return i;
+            } else if ((l = toLong(bigDec)) != null) {
+                return l;
+            } else {
+                return bigDec.doubleValue();
+            }
+        }
+    }
+
+    private Long toLong(BigDecimal val) {
+        try {
+            return val.toBigIntegerExact().longValue();
+        } catch (ArithmeticException e) {
+            return null;
+        }
+    }
+
+    private Integer toInteger(BigDecimal val) {
+        try {
+            return val.intValueExact();
+        } catch (ArithmeticException e) {
+            return null;
+        }
+    }
+
+}

gson/src/main/resources/logback.xml

@@ -7,13 +7,13 @@
         </encoder>
     </appender>
 
-    <logger name="org.springframework" level="WARN" />
-    <logger name="org.springframework.transaction" level="WARN" />
+    <logger name="org.springframework" level="WARN"/>
+    <logger name="org.springframework.transaction" level="WARN"/>
 
     <!-- in order to debug some marshalling issues, this needs to be TRACE -->
-    <logger name="org.springframework.web.servlet.mvc" level="WARN" />
+    <logger name="org.springframework.web.servlet.mvc" level="WARN"/>
 
     <root level="INFO">
-        <appender-ref ref="STDOUT" />
+        <appender-ref ref="STDOUT"/>
     </root>
 </configuration>

gson/src/test/java/org/baeldung/gson/deserialization/HashMapDeserializationUnitTest.java

@@ -0,0 +1,86 @@
+package org.baeldung.gson.deserialization;
+
+import java.lang.reflect.Type;
+import java.util.HashMap;
+
+import org.baeldung.gson.entities.Employee;
+import org.baeldung.gson.serialization.HashMapDeserializer;
+import org.junit.Assert;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonSyntaxException;
+import com.google.gson.internal.LinkedTreeMap;
+import com.google.gson.reflect.TypeToken;
+
+public class HashMapDeserializationUnitTest {
+
+    private static final Logger logger = LoggerFactory.getLogger(HashMapDeserializationUnitTest.class);
+
+    @Test
+    public void whenUsingHashMapClass_thenShouldReturnMapWithDefaultClasses() {
+
+        String jsonString = "{'employee.name':'Bob','employee.salary':10000, 'employee.active':true, "
+          + "'employee':{'id':10, 'name': 'Bob Willis', 'address':'London'}}";
+
+        Gson gson = new Gson();
+        HashMap map = gson.fromJson(jsonString, HashMap.class);
+
+        logger.info("The converted map: {}", map);
+        Assert.assertEquals(4, map.size());
+        Assert.assertEquals(Double.class, map.get("employee.salary").getClass());
+        Assert.assertEquals(LinkedTreeMap.class, map.get("employee").getClass());
+
+    }
+
+    @Test(expected = JsonSyntaxException.class)
+    public void whenUsingJsonStringWithDuplicateKey_thenShouldThrowJsonSyntaxException() {
+
+        String jsonString = "{'employee.name':'Bob', 'employee.name':'Jenny','employee.salary':10000, "
+          + "'employee.active':true, " + "'employee':{'id':10, 'name': 'Bob Willis', 'address':'London'}}";
+
+        Gson gson = new Gson();
+        HashMap map = gson.fromJson(jsonString, HashMap.class);
+
+        logger.info("The converted map: {}", map);
+    }
+
+    @Test
+    public void whenUsingTypeToken_thenShouldReturnMapWithProperClass() {
+
+        String jsonString = "{'Bob':{'id':10, 'name': 'Bob Willis', 'address':'UK'},"
+          + "'Jenny':{'id':10, 'name': 'Jenny McCarthy', 'address':'USA'}, "
+          + "'Steve':{'id':10, 'name': 'Steven Waugh', 'address':'Australia'}}";
+
+        Gson gson = new Gson();
+        Type empMapType = new TypeToken<HashMap<String, Employee>>(){}.getType();
+        HashMap<String, Employee> nameEmployeeMap = gson.fromJson(jsonString, empMapType);
+
+        logger.info("The converted map: {}", nameEmployeeMap);
+        Assert.assertEquals(3, nameEmployeeMap.size());
+        Assert.assertEquals(Employee.class, nameEmployeeMap.get("Bob").getClass());
+    }
+
+    @Test
+    public void whenUsingCustomDeserializer_thenShouldReturnMapWithProperClass() {
+
+        String jsonString = "{'employee.name':'Bob','employee.salary':10000, 'employee.active':true, "
+          + "'employee':{'id':10, 'name': 'Bob Willis', 'address':'London'}}";
+
+        Type type = new TypeToken<HashMap<String, Object>>(){}.getType();
+        Gson gson = new GsonBuilder()
+          .registerTypeAdapter(type, new HashMapDeserializer())
+          .create();
+        HashMap<String, Object> blendedMap = gson.fromJson(jsonString, type);
+
+        logger.info("The converted map: {}", blendedMap);
+        Assert.assertEquals(4, blendedMap.size());
+        Assert.assertEquals(Integer.class, blendedMap.get("employee.salary").getClass());
+        Assert.assertEquals(Employee.class, blendedMap.get("employee").getClass());
+
+    }
+
+}

gson/src/test/resources/logback-test.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <logger name="org.springframework" level="WARN"/>
+    <logger name="org.springframework.transaction" level="WARN"/>
+
+    <!-- in order to debug some marshalling issues, this needs to be TRACE -->
+    <logger name="org.springframework.web.servlet.mvc" level="WARN"/>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT"/>
+    </root>
+</configuration>