Generate JSON schema from Java class

Question

I have a POJO class:

public class Stock {
 int id;
 String name;
 Date date;
}

Are there any annotations or development framework/API that can co

Answer 1

Use JJschema. It can generate draft 4 compliant JSON schemas. Refer this post http://wilddiary.com/generate-json-schema-from-java-class/ for details.

Though Jackson Json Schema module can too generate schema but it can, as of today, only generate draft 3 compliant schemas only.

Answer 2

public static String getJsonSchema(Class clazz) throws IOException {
         Field[] fields = clazz.getDeclaredFields();
         List<Map<String,String>> map=new ArrayList<Map<String,String>>();
         for (Field field : fields) {
             HashMap<String, String> objMap=new  HashMap<String, String>();
             objMap.put("name", field.getName());
             objMap.put("type", field.getType().getSimpleName());
             objMap.put("format", "");
             map.add(objMap);
         }
         ObjectMapper mapper = new ObjectMapper();
         String json = mapper.writeValueAsString(map);

       return json;
    }

Answer 3

One such tool is Jackson JSON Schema module:

https://github.com/FasterXML/jackson-module-jsonSchema

which uses Jackson databind's POJO introspection to traverse POJO properties, taking into account Jackson annotations, and produces a JSON Schema object, which may then be serialized as JSON or used for other purposes.