Spring REST 1: JSON

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What is JSON?

  • JavaScript Object Notation
  • Lightweight data format for storing and exchanging data
  • JSON is plain text data

JSON Example

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{
    // Numbers: no quotes
    "id": 14,
    // String: in double quotes
    "firstName": "Mario",
    "lastName": "Rossi",
    // Boolean: true / false 
    "active": true
    // Nested JSON object
    "address": {
        "steet": "100 Main St",
        "city": "Philadelphia",
        "state": "Pennsylvania",
        "zip": "19103",
        "country": "USA"
    }
    // Array: use square brackets[...]
    "languages": ["Java","C#","Python","Javascript"]
    // null
}

JSON Data Binding

  • Data binding is the process of converting JSON data to a Java POJO, also know as Mapping, Serialization/Deserialization, Marshalling/Unmarshalling

    JSON Data Binding with Jackson

  • Spring uses the Jackson Project behind the scenes
  • Jackson handles data binding between JSON and Java POJO
  • By default, Jackson will call appropriate getter/setter method
    • JSON to Java POJO
      • call setter methods on POJO(automatically)
    • Java POJO to JSON
      • call getter methods on POJO(automatically)