BAEL-9214: conversion from json object to json array (#18672)

Co-authored-by: sverma1-godaddy <[email protected]>

Author: sgrverma23

json-modules/json-conversion/src/main/java/com/baeldung/jsonobjecttojsonarray/GsonConverter.java

@@ -0,0 +1,19 @@
+package com.baeldung.jsonobjecttojsonarray;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import org.json.JSONObject;
+
+public class GsonConverter {
+
+    JsonArray convertToKeyValueArray(JSONObject jsonObject) {
+        JsonArray result = new JsonArray();
+        jsonObject.keySet().forEach(key -> {
+            JsonObject entry = new JsonObject();
+            entry.addProperty("key", key);
+            entry.add("value", com.google.gson.JsonParser.parseString(jsonObject.get(key).toString()));
+            result.add(entry);
+        });
+        return result;
+    }
+}

json-modules/json-conversion/src/main/java/com/baeldung/jsonobjecttojsonarray/JacksonConverter.java

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+package com.baeldung.jsonobjecttojsonarray;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.json.JSONObject;
+
+public class JacksonConverter {
+
+    ArrayNode convertToArray(JSONObject jsonObject) {
+        ObjectMapper mapper = new ObjectMapper();
+        JsonNode jsonNode = mapper.convertValue(jsonObject.toMap(), JsonNode.class);
+
+        ArrayNode result = mapper.createArrayNode();
+        jsonNode.fields().forEachRemaining(entry -> {
+            ObjectNode obj = mapper.createObjectNode();
+            obj.put("key", entry.getKey());
+            obj.set("value", entry.getValue());
+            result.add(obj);
+        });
+
+        return result;
+    }
+}

json-modules/json-conversion/src/main/java/com/baeldung/jsonobjecttojsonarray/OrgJsonConverter.java

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+package com.baeldung.jsonobjecttojsonarray;
+
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+public class OrgJsonConverter {
+
+    JSONArray convertValuesToArray(JSONObject jsonObject) {
+        return new JSONArray(jsonObject.toMap().values());
+    }
+
+    JSONArray convertToEntryArray(JSONObject jsonObject) {
+        JSONArray result = new JSONArray();
+        for (String key : jsonObject.keySet()) {
+            JSONObject entry = new JSONObject();
+            entry.put("key", key);
+            entry.put("value", jsonObject.get(key));
+            result.put(entry);
+        }
+        return result;
+    }
+}

json-modules/json-conversion/src/test/java/com/baeldung/jsonobjecttojsonarray/GsonConverterTest.java

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+package com.baeldung.jsonobjecttojsonarray;
+
+import com.google.gson.JsonArray;
+import org.json.JSONObject;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+class GsonConverterTest {
+
+    @Test
+    void givenJSONObject_whenConvertToKeyValueArray_thenJsonArrayWithObjects() {
+        JSONObject jsonObject = new JSONObject();
+        jsonObject.put("brand", "Tesla");
+        jsonObject.put("year", 2024);
+
+        GsonConverter converter = new GsonConverter();
+        System.out.println("before :"+jsonObject);
+        JsonArray result = converter.convertToKeyValueArray(jsonObject);
+
+        System.out.println("here :"+result);
+
+        assertEquals(2, result.size());
+        assertEquals("year", result.get(0).getAsJsonObject().get("key").getAsString());
+    }
+}

json-modules/json-conversion/src/test/java/com/baeldung/jsonobjecttojsonarray/JacksonConverterTest.java

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+package com.baeldung.jsonobjecttojsonarray;
+
+import org.json.JSONObject;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+class JacksonConverterTest {
+
+    @Test
+    void givenJSONObject_whenConvertToArray_thenArrayNodeOfKeyValueObjects() {
+        JSONObject jsonObject = new JSONObject();
+        jsonObject.put("country", "India");
+        jsonObject.put("code", "IN");
+
+        JacksonConverter converter = new JacksonConverter();
+        ArrayNode result = converter.convertToArray(jsonObject);
+
+        assertEquals(2, result.size());
+        assertEquals("country", result.get(0).get("key").asText());
+    }
+}

json-modules/json-conversion/src/test/java/com/baeldung/jsonobjecttojsonarray/OrgJsonConverterTest.java

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+package com.baeldung.jsonobjecttojsonarray;
+
+import org.json.JSONObject;
+import org.json.JSONArray;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+public class OrgJsonConverterTest {
+
+    @Test
+    void givenFlatJSONObject_whenConvertValues_thenJSONArrayOfValues() {
+        JSONObject jsonObject = new JSONObject();
+        jsonObject.put("id", 1);
+        jsonObject.put("name", "Alice");
+
+        OrgJsonConverter converter = new OrgJsonConverter();
+        JSONArray result = converter.convertValuesToArray(jsonObject);
+
+        assertEquals(2, result.length());
+        assertTrue(result.toList().contains("Alice"));
+    }
+
+    @Test
+    void givenFlatJSONObject_whenConvertToEntryArray_thenJSONArrayOfObjects() {
+        JSONObject jsonObject = new JSONObject();
+        jsonObject.put("language", "Java");
+        jsonObject.put("framework", "Spring");
+
+        OrgJsonConverter converter = new OrgJsonConverter();
+        JSONArray result = converter.convertToEntryArray(jsonObject);
+
+        assertEquals(2, result.length());
+        assertEquals("framework", result.getJSONObject(0).get("key"));
+    }
+}