Steps

1. mkdir <project-dir>

2. cd <project-dir>

3. mkdir lib

4. Download JSON processing library dependencies and put them into the lib folder.

   1. com.fasterxml.jackson

      1. jackson-core-2.8.8.jar

      2. jackson-annotations-2.8.8.jar

      3. jackson-databind-2.8.8.jar

   2. com.google.gson

      1. gson-2.8.0.jar

   3. javax.json

      1. javax.json-1.0.4.jar

   4. org.json

      1. json-20160810.jar

5. Choose a JSON library from the above list and download its related JARs.

   1. Start with Jackson or Gson, because javax.json and org.json doesn’t support direct object serialization/deserialization.

6. Import the JARs as dependencies in your IDE project.

7. Create a Message class.

   1. It has an id field of type Integer

   2. and a text field of type String.

   3. Implement toString.

8. Create a Main class with a main method which works as follows:

   1. Deserializes the contents of single.json into a Message instance.

      single.json

      {
      	"id": 123,
      	"text": "message123"
      }

   2. Prints out the Message instance to stdout.

   3. Serialalizes the Message object to a file called output-single.json.

   4. After this it should deserialize the contents of multiple.json into a List<Message>.

      multiple.json

      [
      	{"id": 234, "text": "message234"},
      	{"id": 345, "text": "message345"},
      	{"id": 456, "text": "message456"},
      ]

   5. Prints out the List<Message> to stdout.

   6. Serialalizes the List<Message> object to a file called output-multiple.json.

9. Try to use multiple JSON libraries from the above list.

10. Try to use InputStream and OutputStream objects and their sub-classes.