Jackson Full Data Binding

Internal

• Jackson

JSON to Java

import com.fasterxml.jackson.databind.ObjectMapper;

ObjectMapper om = new ObjectMapper();
Token token = on.readValue(inputStream, Token.class);

This is a generic conversion method, assuming that the JSON content matches the internal structure of the type <T>:

public static <T> T fromJson(String json, Class<? extends T> c) throws JsonConversionException {

    try {
        ObjectMapper objectMapper = new ObjectMapper();
        return objectMapper.readValue(new ByteArrayInputStream(json.getBytes()), c);
    }
    catch (Exception e) {
       throw new JsonConversionException(e);
    }
}

To enable generic type information (like "Map<String,Object>"), you have to use TypeReference container as explained above.

Java to JSON

ObjectMapper will introspect a Java object coded according to the Java Beans conventions and output it as JSON content.

The method names (without the "get") will be used as field names.

Example:

import com.fasterxml.jackson.databind.ObjectMapper;

ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectMapper om = new ObjectMapper();
Object root = ... // some hierarchical object
om.writeValue(baos, root);
System.out.println(new String(baos.toByteArray()));