jackson的使用

jackson工具类
  1 package com.booway.util;
  2 
  3 import java.util.List;
  4 
  5 import com.fasterxml.jackson.core.JsonProcessingException;
  6 import com.fasterxml.jackson.databind.JavaType;
  7 import com.fasterxml.jackson.databind.JsonNode;
  8 import com.fasterxml.jackson.databind.ObjectMapper;
  9 
 10 /**
 11  * json工具
 12  * @author wzh
 13  *
 14  */
 15 public class JsonUtils {
 16 
 17     private static final ObjectMapper MAPPER = new ObjectMapper();
 18 
 19     public static String objectToJson(Object data) {
 20         String string = null;
 21         try {
 22             string = MAPPER.writeValueAsString(data);
 23         } catch (JsonProcessingException e) {
 24             e.printStackTrace();
 25         }
 26         return string;
 27     }
 28     
 29     public static <T> T jsonToPojo(String jsonData, Class<T> beanType) {
 30         T t = null;
 31         try {
 32            t = MAPPER.readValue(jsonData, beanType);
 33             return t;
 34         } catch (Exception e) {
 35             e.printStackTrace();
 36         }
 37         return t;
 38     }
 39     
 40     public static <T>List<T> jsonToList(String jsonData, Class<?> target, Class<T> beanType) {
 41         
 42         JavaType javaType = MAPPER.getTypeFactory().constructParametricType(target, beanType);
 43         List<T> list = null;
 44         try {
 45             list = MAPPER.readValue(jsonData, javaType);
 46         } catch (Exception e) {
 47             e.printStackTrace();
 48         }
 49         return list;
 50     }
 51     
 52     private static BwjsResult build(boolean successful, String message, Object data) {
 53         
 54         return new BwjsResult(successful, message, data);
 55     }
 56     
 57     public static BwjsResult formatToPojo(String jsonData, Class<?> clazz) {
 58         try {
 59             if (clazz == null) {
 60                 return MAPPER.readValue(jsonData, BwjsResult.class);
 61             }
 62             JsonNode jsonNode = MAPPER.readTree(jsonData);
 63             JsonNode data = jsonNode.get("data");
 64             Object obj = null;
 65             if (clazz != null) {
 66                 if (data.isObject()) {
 67                     obj = MAPPER.readValue(data.traverse(), clazz);
 68                 } else if (data.isTextual()) {
 69                     obj = MAPPER.readValue(data.asText(), clazz);
 70                 }
 71             }
 72             return build(jsonNode.get("successful").booleanValue(), jsonNode.get("msg").asText(), obj);
 73         } catch (Exception e) {
 74             return null;
 75         }
 76     }
 77 
 78     public static BwjsResult format(String json) {
 79         try {
 80             return MAPPER.readValue(json, BwjsResult.class);
 81         } catch (Exception e) {
 82             e.printStackTrace();
 83         }
 84         return null;
 85     }
 86 
 87     public static BwjsResult formatToList(String jsonData, Class<?> clazz) {
 88         try {
 89             JsonNode jsonNode = MAPPER.readTree(jsonData);
 90             JsonNode data = jsonNode.get("data");
 91             Object obj = null;
 92             if (data.isArray() && data.size() > 0) {
 93                 obj = MAPPER.readValue(data.traverse(),
 94                         MAPPER.getTypeFactory().constructCollectionType(List.class, clazz));
 95             }
 96             return build(jsonNode.get("successful").booleanValue(), jsonNode.get("msg").asText(), obj);
 97         } catch (Exception e) {
 98             return null;
 99         }
100     }
101 }