add: parsing json

core-groovy/src/main/groovy/com/baeldung/json/Account.groovy

@@ -0,0 +1,7 @@
+package com.baeldung.json
+
+class Account {
+    String id
+    BigDecimal value
+    Date createdAt
+}

core-groovy/src/main/groovy/com/baeldung/json/JsonParser.groovy

@@ -0,0 +1,36 @@
+package com.baeldung.json
+
+import groovy.json.JsonGenerator
+import groovy.json.JsonOutput
+import groovy.json.JsonParserType
+import groovy.json.JsonSlurper
+
+class JsonParser {
+
+    Account toObject(String json) {
+        JsonSlurper jsonSlurper = new JsonSlurper()
+        jsonSlurper.parseText(json) as Account
+    }
+
+    Account toObjectWithIndexOverlay(String json) {
+        JsonSlurper jsonSlurper = new JsonSlurper(type: JsonParserType.INDEX_OVERLAY)
+        jsonSlurper.parseText(json) as Account
+    }
+
+    String toJson(Account account) {
+        JsonOutput.toJson(account)
+    }
+
+    String toJson(Account account, String dateFormat, String... fieldsToExclude) {
+        JsonGenerator generator = new JsonGenerator.Options()
+                .dateFormat(dateFormat)
+                .excludeFieldsByName(fieldsToExclude)
+                .build()
+        generator.toJson(account)
+    }
+
+    String prettyfy(String json) {
+        JsonOutput.prettyPrint(json)
+    }
+
+}