How to Encode and Decode JSON Byte Array
The typical way to send binary in JSON is to base64 encode it. Java provides different ways to Base64 encode and decode a byte[]. One of these is DatatypeConverter.
Suppose we have a JSON Array as listed below:
{
"menu": {
"id": "file",
"value": "File",
"popup": {
"menuitem": [
{"value": "New", "onclick": "CreateNewDoc()"},
{"value": "Open", "onclick": "OpenDoc()"},
{"value": "Close", "onclick": "CloseDoc()"}
]
}
}
}
Encode JSON as Base64
To encode the above JSON, we would use
String base64Encoded = DatatypeConverter.printBase64Binary(jsonBytes);
Decode Base64 JSON
To decode a base64 encoded JSON, we would use
byte[] base64Decoded = DatatypeConverter.parseBase64Binary(base64Encoded);
Example code:
import javax.xml.bind.DatatypeConverter;
public class JsonEncodeDecode {
public static void main(String[] args) {
String json = "{\"menu\": {\n" +
" \"id\": \"file\",\n" +
" \"value\": \"File\",\n" +
" \"popup\": {\n" +
" \"menuitem\": [\n" +
" {\"value\": \"New\", \"onclick\": \"CreateNewDoc()\"},\n" +
" {\"value\": \"Open\", \"onclick\": \"OpenDoc()\"},\n" +
" {\"value\": \"Close\", \"onclick\": \"CloseDoc()\"}\n" +
" ]\n" +
" }\n" +
"}}";
byte[] bytes = json.getBytes();
String base64Encoded = DatatypeConverter.printBase64Binary(bytes);
System.out.println("Encoded Json:\n");
System.out.println(base64Encoded + "\n");
byte[] base64Decoded = DatatypeConverter.parseBase64Binary(base64Encoded);
System.out.println("Decoded Json:\n");
System.out.println(new String(base64Decoded));
}
}
Output of encoded JSON:
eyJtZW51IjogewogICJpZCI6ICJmaWxlIiwKICAidmFsdW
Note:
The encoded JSON is truncated for sake of neatness, otherwise it's a very long string.
Output of decoded JSON:
{
"menu": {
"id": "file",
"value": "File",
"popup": {
"menuitem": [
{"value": "New", "onclick": "CreateNewDoc()"},
{"value": "Open", "onclick": "OpenDoc()"},
{"value": "Close", "onclick": "CloseDoc()"}
]
}
}
}