使用com.fasterxml.jackson将对象转换为JSON字符串或反转

import com.fasterxml.jackson.databind.ObjectMapper;

Iterable<Area> areaItera = areaRepository.findAll();

StringWriter writer = new StringWriter();
ObjectMapper mapper = new ObjectMapper();
try {
mapper.writeValue(writer, areaItera);
} catch (JsonGenerationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JsonMappingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

System.out.println("areaString:"+writer.toString());

Map<String,Map<String, Object>> blockMap = mapper.readValue(writer.toString(), Map.class);

System.out.println(blockMap.toString());