Merge pull request #7157 from anuraggoyal1/master

[BAEL-3002] Comparing 2 JSON objects with Jackson

jackson-2/src/test/java/com/baeldung/jackson/json/compare/JsonCompareUnitTest.java

@@ -0,0 +1,126 @@
+package com.baeldung.jackson.json.compare;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.Comparator;
+
+import org.junit.Test;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.NumericNode;
+import com.fasterxml.jackson.databind.node.TextNode;
+
+public class JsonCompareUnitTest {
+
+    @Test
+    public void givenTwoSameJsonDataObjects_whenCompared_thenAreEqual() throws IOException {
+        ObjectMapper mapper = new ObjectMapper();
+
+        String s1 = "{\"employee\": {\"id\": \"1212\",\"fullName\": \"John Miles\", \"age\": 34 }}";
+        String s2 = "{\"employee\": {\"id\": \"1212\",\"age\": 34, \"fullName\": \"John Miles\" }}";
+
+        JsonNode actualObj1 = mapper.readTree(s1);
+        JsonNode actualObj2 = mapper.readTree(s2);
+
+        assertEquals(actualObj1, actualObj2);
+
+    }
+
+    @Test
+    public void givenTwoSameNestedJsonDataObjects_whenCompared_thenEqual() throws IOException {
+        ObjectMapper mapper = new ObjectMapper();
+
+        String s1 = "{\"employee\": {\"id\": \"1212\",\"fullName\": \"John Miles\",\"age\": 34, \"contact\":{\"email\": \"john@xyz.com\",\"phone\": \"9999999999\"} }}";
+        String s2 = "{\"employee\": {\"id\": \"1212\",\"fullName\": \"John Miles\",\"age\": 34, \"contact\":{\"email\": \"john@xyz.com\",\"phone\": \"9999999999\"} }}";
+
+        JsonNode actualObj1 = mapper.readTree(s1);
+        JsonNode actualObj2 = mapper.readTree(s2);
+
+        assertEquals(actualObj1, actualObj2);
+
+    }
+
+    @Test
+    public void givenTwoSameListJsonDataObjects_whenCompared_thenEqual() throws IOException {
+        ObjectMapper mapper = new ObjectMapper();
+
+        String s1 = "{\"employee\": {\"id\": \"1212\",\"fullName\": \"John Miles\",\"age\": 34, \"skills\":[\"Java\", \"C++\", \"Python\"] }}";
+        String s2 = "{\"employee\": {\"id\": \"1212\",\"fullName\": \"John Miles\",\"age\": 34, \"skills\":[\"Java\", \"C++\", \"Python\"] }}";
+
+        JsonNode actualObj1 = mapper.readTree(s1);
+        JsonNode actualObj2 = mapper.readTree(s2);
+
+        assertEquals(actualObj1, actualObj2);
+
+    }
+
+    @Test
+    public void givenTwoJsonDataObjects_whenComparedUsingCustomNumericNodeComparator_thenEqual() throws IOException {
+        ObjectMapper mapper = new ObjectMapper();
+
+        String s1 = "{\"name\": \"John\",\"score\":5.0}";
+        String s2 = "{\"name\": \"John\",\"score\":5}";
+        JsonNode actualObj1 = mapper.readTree(s1);
+        JsonNode actualObj2 = mapper.readTree(s2);
+
+        NumericNodeComparator cmp = new NumericNodeComparator();
+
+        assertNotEquals(actualObj1, actualObj2);
+        assertTrue(actualObj1.equals(cmp, actualObj2));
+
+    }
+    
+    public class NumericNodeComparator implements Comparator<JsonNode> {
+        @Override
+        public int compare(JsonNode o1, JsonNode o2) {
+            if (o1.equals(o2)) {
+                return 0;
+            }
+            if ((o1 instanceof NumericNode) && (o2 instanceof NumericNode)) {
+                Double d1 = ((NumericNode) o1).asDouble();
+                Double d2 = ((NumericNode) o2).asDouble();
+                if (d1.compareTo(d2) == 0) {
+                    return 0;
+                }
+            }
+            return 1;
+        }
+    }
+    
+    @Test
+    public void givenTwoJsonDataObjects_whenComparedUsingCustomTextNodeComparator_thenEqual() throws IOException {
+        ObjectMapper mapper = new ObjectMapper();
+
+        String s1 = "{\"name\": \"JOHN\",\"score\":5}";
+        String s2 = "{\"name\": \"John\",\"score\":5}";
+        JsonNode actualObj1 = mapper.readTree(s1);
+        JsonNode actualObj2 = mapper.readTree(s2);
+
+        TextNodeComparator cmp = new TextNodeComparator();
+
+        assertNotEquals(actualObj1, actualObj2);
+        assertTrue(actualObj1.equals(cmp, actualObj2));
+
+    }
+    
+    public class TextNodeComparator implements Comparator<JsonNode> {
+        @Override
+        public int compare(JsonNode o1, JsonNode o2) {
+            if (o1.equals(o2)) {
+                return 0;
+            }
+            if ((o1 instanceof TextNode) && (o2 instanceof TextNode)) {
+                String s1 = ((TextNode) o1).asText();
+                String s2 = ((TextNode) o2).asText();
+                if (s1.equalsIgnoreCase(s2)) {
+                    return 0;
+                }
+            }
+            return 1;
+        }
+    }
+}