[BAEL-3233] Add missing code snippets from the Jackson ObjectMapper art.

Also: Corrected rendering problem in the readme and formatted using eclipse

jackson-simple/README.md

@@ -3,6 +3,7 @@
 This module contains articles about Jackson that are also part of the Jackson Ebook.
 
 ### The Course
+
 The "REST With Spring" Classes: http://bit.ly/restwithspring
 
 ### Relevant Articles: 

jackson-simple/src/test/java/com/baeldung/jackson/objectmapper/JavaReadWriteJsonExampleUnitTest.java

@@ -1,20 +1,29 @@
 package com.baeldung.jackson.objectmapper;
 
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
+
+import java.io.File;
+import java.net.URL;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
 import com.baeldung.jackson.objectmapper.dto.Car;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import org.junit.Test;
-
-import java.util.List;
-import java.util.Map;
-
-import static org.hamcrest.Matchers.containsString;
-import static org.hamcrest.Matchers.equalTo;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertThat;
 
 public class JavaReadWriteJsonExampleUnitTest {
+    @Rule
+    public TemporaryFolder folder = new TemporaryFolder();
+
     final String EXAMPLE_JSON = "{ \"color\" : \"Black\", \"type\" : \"BMW\" }";
     final String LOCAL_JSON = "[{ \"color\" : \"Black\", \"type\" : \"BMW\" }, { \"color\" : \"Red\", \"type\" : \"BMW\" }]";
 
@@ -27,6 +36,19 @@ public class JavaReadWriteJsonExampleUnitTest {
         assertThat(carAsString, containsString("renault"));
     }
 
+    @Test
+    public void whenWriteToFile_thanCorrect() throws Exception {
+        File resultFile = folder.newFile("car.json");
+
+        ObjectMapper objectMapper = new ObjectMapper();
+        Car car = new Car("yellow", "renault");
+        objectMapper.writeValue(resultFile, car);
+
+        Car fromFile = objectMapper.readValue(resultFile, Car.class);
+        assertEquals(car.getType(), fromFile.getType());
+        assertEquals(car.getColor(), fromFile.getColor());
+    }
+
     @Test
     public void whenReadJsonToJava_thanCorrect() throws Exception {
         final ObjectMapper objectMapper = new ObjectMapper();
@@ -66,4 +88,26 @@ public class JavaReadWriteJsonExampleUnitTest {
             assertNotNull(key);
         }
     }
+
+    @Test
+    public void wheReadFromFile_thanCorrect() throws Exception {
+        File resource = new File("src/test/resources/json_car.json");
+
+        ObjectMapper objectMapper = new ObjectMapper();
+        Car fromFile = objectMapper.readValue(resource, Car.class);
+
+        assertEquals("BMW", fromFile.getType());
+        assertEquals("Black", fromFile.getColor());
+    }
+
+    @Test
+    public void wheReadFromUrl_thanCorrect() throws Exception {
+        URL resource = new URL("file:src/test/resources/json_car.json");
+
+        ObjectMapper objectMapper = new ObjectMapper();
+        Car fromFile = objectMapper.readValue(resource, Car.class);
+
+        assertEquals("BMW", fromFile.getType());
+        assertEquals("Black", fromFile.getColor());
+    }
 }

jackson-simple/src/test/resources/.gitignore

@@ -1,13 +0,0 @@
-*.class
-
-#folders#
-/target
-/neoDb*
-/data
-/src/main/webapp/WEB-INF/classes
-*/META-INF/*
-
-# Packaged files #
-*.jar
-*.war
-*.ear

jackson-simple/src/test/resources/json_car.json

@@ -0,0 +1,4 @@
+{
+  "color": "Black",
+  "type": "BMW"
+}