json转换大全 复制直接用

pom 包导入：

<!-- json解析 -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>${fastjson.version}</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>${jackson-databind.version}</version>
    </dependency>

package com.sitech.pos.smartcitypayposcenter.util;

import com.alibaba.fastjson.serializer.SerializeConfig;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.alibaba.fastjson.serializer.SimpleDateFormatSerializer;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.node.ObjectNode;
import lombok.extern.slf4j.Slf4j;

import java.io.IOException;
import java.util.*;

/**

• @author GZY json工具类
  */
  @Slf4j
  public class JsonUtils {

  private static SerializeConfig serialConfig = new SerializeConfig();

  private static SerializerFeature[] serialFeatures = null;

  private static final String DATE_FORMART = “yyyy-MM-dd HH:mm:ss”;

  static {

   //允许输出空属性
   serialFeatures = new SerializerFeature[]{SerializerFeature.WriteMapNullValue, SerializerFeature.WriteNullListAsEmpty};
  
   //java.util.Date的转换
   serialConfig.put(Date.class, new SimpleDateFormatSerializer(DATE_FORMART));
  

  }

  /**

  • 普通json转map
  • 例子 {“phone_no”:“15074917062”,“order_date”:“20150316145250”,“imei”

  •  *                :"sasassdsadsadfdssf","external_order_id":"jd222233331",
    

  •  *                "op_type":"01","login_no":"jdop001","chn_code":"11221"}
    

  • @param
  • @return
    */
    public static Map<String, String> json2Map(String param) {
    Map<String, String> parameterMap = new LinkedHashMap<String, String>();
    if (param != null && !param.equals(“null”)) {
    if (param.length() > 2) {
    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    try {
    parameterMap = objectMapper.readValue(param,
    new TypeReference<LinkedHashMap<String, String>>() {
    });
    } catch (Exception e) {
    log.error(“json解析异常” + param, e);
    }
    }
    }
    return parameterMap;
    }

  /**

  • 把JavaBean转换为json字符串

  • @param obj 要转的javabean

  • @return json串
    */
    public static String bean2json(Object obj) {

    if (obj == null){
    return “”;
    }
    ObjectMapper m = new ObjectMapper();
    m.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    // 由于下面这行代码会导致bean中设置的json注解失效，所以注释掉
    // m.setAnnotationIntrospector(new JaxbAnnotationIntrospector(TypeFactory.defaultInstance()));
    try {
    //return m.writeValueAsString(obj).replaceAll(“”“null”“|“null”|null”, “”“”);
    return m.writeValueAsString(obj);
    } catch (JsonProcessingException e) {
    // TODO Auto-generated catch block
    log.error(“json解JsonProcessingException异常”, e);
    }
    return “”;
    }

  /**

  • bean转普通json串
  • @param json 要转的josn
  • @return obj
    */
    public static Object readJson(String json, Class<?> clz) {
    return com.alibaba.fastjson.JSON.parseObject(json, clz);
    }

  /**

  • 使用泛型方法，把json字符串转换为相应的JavaBean对象。

  • (1)转换为普通JavaBean：readValue(json,Student.class)

  • (2)转换为List,如List,将第二个参数传递为Student

  • [].class.然后使用Arrays.asList();方法把得到的数组转换为特定类型的List

  • @param jsonStr

  • @param collectionClass

  • @return
    */
    @SuppressWarnings(“unchecked”)
    public static T readJson(String jsonStr, Class collectionClass,
    Class… elementClasses) {
    ObjectMapper mapper = new ObjectMapper();
    mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

    JavaType javaType = mapper.getTypeFactory().constructParametricType(
    collectionClass, elementClasses);

    try {
    return (T) mapper.readValue(jsonStr, javaType);
    } catch (JsonParseException e) {
    // TODO Auto-generated catch block
    log.error(“json解析JsonParseException异常”, e);
    } catch (JsonMappingException e) {
    // TODO Auto-generated catch block
    log.error(“json解析JsonMappingException异常”, e);
    } catch (IOException e) {
    // TODO Auto-generated catch block
    log.error(“json解析IOException异常”, e);
    }
    return null;

  }

  /**

  • json数组转List

  • @param jsonStr

  • @param valueTypeRef

  • @return
    */
    @SuppressWarnings(“unchecked”)
    public static T readValue(String jsonStr, TypeReference valueTypeRef) {
    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

    try {
    return (T) objectMapper.readValue(jsonStr, valueTypeRef);
    } catch (Exception e) {
    log.error(“json解析Exception异常”, e);
    }

    return null;
    }

  /**

  • javabean转json串
  • @param obj 要转的javabean
  • @return json串
    */
    public static String simpleObjectToJsonStr(Object obj) {
    return toJsonStrByFastjson(obj);
    }

  /**

  • 将对象转化为Json String
  • @param obj
  • @return String
    */
    public static String toJson(Object obj) {
    return toJsonStrByFastjson(obj);
    }

  private static String toJsonStrByFastjson(Object obj) {
  try {
  return com.alibaba.fastjson.JSON.toJSONString(obj, serialConfig, serialFeatures);
  } catch (Exception e) {
  log.error(“转换JSON失败”, e);
  return “”;
  }
  }

  /**

  • javabean转json串
  • @param list <List<?>> 要转的javabean集合
  • @return json串
    */
    public static String simpleListToJsonStr(List<?> list) {
    if (list == null || list.size() == 0) {
    return “[]”;
    }
    return toJsonStrByFastjson(list);
    }

  public static String getNodeFromJson(String name, String json) {
  ObjectMapper objectMapper = new ObjectMapper();
  try {
  JsonNode node = objectMapper.readTree(json);
  JsonNode v = node.findValues(name).get(0);
  if (null != v) {
  if (v.isValueNode()) {
  return v.asText();
  } else {
  return v.toString();
  }
  }
  } catch (Exception e) {
  e.printStackTrace();
  }
  return “”;
  }

  /**

  • 向json的根目录下获取第一级的name对应的值
  • @param name
  • @param json
  • @return
    */
    public static String getNodeFromJsonRoot(String name, String json) {
    ObjectMapper objectMapper = new ObjectMapper();
    try {
    JsonNode node = objectMapper.readTree(json);
    JsonNode v = node.findValues(name).get(0);
    if (null != v) {
    if (v.isValueNode()) {
    return v.asText();
    } else {
    return v.toString();
    }
    }
    } catch (Exception e) {
    e.printStackTrace();
    }
    return “”;
    }

  /**

  • 向json的根目录下第一级的name设置对应的值value
  • @param name
  • @param value
  • @param json
  • @return
    */
    public static String setNodeValueToJsonRoot(String name, String value, String json) {
    ObjectMapper objectMapper = new ObjectMapper();
    try {
    JsonNode node = objectMapper.readTree(json);
    if (node instanceof ObjectNode) {
    ((ObjectNode) node).put(name, value);
    }
    return node.toString();
    } catch (Exception e) {
    e.printStackTrace();
    }
    return “”;
    }

  /**

  • 转换复杂类型json map 嵌套，list 不支持 jingcy

  • @param jsonString

  • @return
    */
    public static HashMap<String, Object> fromJson2Map(String jsonString) {
    HashMap jsonMap = com.alibaba.fastjson.JSON.parseObject(jsonString, HashMap.class);

    HashMap<String, Object> resultMap = new HashMap<String, Object>();
    for (Iterator iter = jsonMap.keySet().iterator(); iter.hasNext(); ) {
    String key = (String) iter.next();
    if (jsonMap.get(key) instanceof com.alibaba.fastjson.JSONObject) {
    resultMap.put(key, fromJson2Map(jsonMap.get(key).toString()));

     } else {
         Object o = jsonMap.get(key);
         resultMap.put(key, jsonMap.get(key));
     }
    

    }
    return resultMap;
    }

  /**

  • 转换复杂类型json map 嵌套，list 不支持 jingcy
  • @param map
  • @return
    */
    public static String fromMap2Json(Map map) {
    return com.alibaba.fastjson.JSON.toJSONString(map);
    }

  public static Object json2Object(String json, Class calssz) {
  return com.alibaba.fastjson.JSON.parseObject(json, calssz);
  }

  /**

  • 将 Map 转换为 JSON

  • @param map

  • @return
    */
    public static String mapToJson(Map map) {

    ObjectMapper objectMapper = new ObjectMapper();
    try {
    return objectMapper.writeValueAsString(map);
    } catch (Exception e) {
    e.printStackTrace();
    }
    return “”;
    }

  public static Map<String, Object> pojo2map(Object obj){
  ObjectMapper objectMapper = new ObjectMapper();
  Map<String, Object> map = objectMapper.convertValue(obj, Map.class);
  return map;
  }

}