您应该使用JsonWriter而不是JsonGenerator。
替换这些行:
JsonGeneratorFactory jf = Json.createGeneratorFactory(properties);
JsonGenerator jg = jf.createGenerator(sw);
jg.write(jobj).close();
用这些:
JsonWriterFactory writerFactory = Json.createWriterFactory(properties);
JsonWriter jsonWriter = writerFactory.createWriter(sw);
jsonWriter.writeObject(jobj);
jsonWriter.close();