基于JSON和java对象的互转方法

import java.beans.IntrospectionException;import java.beans.Introspector;import java.beans.PropertyDescriptor;import java.util.ArrayList;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Set;import org.json.JSONObject;/*** Json工具类，实现了实体类和Json数据格式之间的互转功能 使用实例：<br>*/public class JsonUtils { /**  * 将一个实体类对象转换成Json数据格式  *   * @param bean  *   需要转换的实体类对象  * @return 转换后的Json格式字符串  */ private static String beanToJson(Object bean) {  StringBuilder json = new StringBuilder();  json.append("{");  PropertyDescriptor[] props = null;  try {   props = Introspector.getBeanInfo(bean.getClass(), Object.class)     .getPropertyDescriptors();  } catch (IntrospectionException e) {  }  if (props != null) {   for (int i = 0; i < props.length; i++) {    try {     String name = objToJson(props[i].getName());     String value = objToJson(props[i].getReadMethod()       .invoke(bean));     json.append(name);     json.append(":");     json.append(value);     json.append(",");    } catch (Exception e) {    }   }   json.setCharAt(json.length() - 1, '}');  } else {   json.append("}");  }  return json.toString(); } /**  * 将一个List对象转换成Json数据格式返回  *   * @param list  *   需要进行转换的List对象  * @return 转换后的Json数据格式字符串  */ private static String listToJson(List<?> list) {  StringBuilder json = new StringBuilder();  json.append("[");  if (list != null && list.size() > 0) {   for (Object obj : list) {    json.append(objToJson(obj));    json.append(",");   }   json.setCharAt(json.length() - 1, ']');  } else {   json.append("]");  }  return json.toString(); } /**  * 将一个对象数组转换成Json数据格式返回  *   * @param array  *   需要进行转换的数组对象  * @return 转换后的Json数据格式字符串  */ private static String arrayToJson(Object[] array) {  StringBuilder json = new StringBuilder();  json.append("[");  if (array != null && array.length > 0) {   for (Object obj : array) {    json.append(objToJson(obj));    json.append(",");   }   json.setCharAt(json.length() - 1, ']');  } else {   json.append("]");  }  return json.toString(); } /**  * 将一个Map对象转换成Json数据格式返回  *   * @param map  *   需要进行转换的Map对象  * @return 转换后的Json数据格式字符串  */ private static String mapToJson(Map<?, ?> map) {  StringBuilder json = new StringBuilder();  json.append("{");  if (map != null && map.size() > 0) {   for (Object key : map.keySet()) {    json.append(objToJson(key));    json.append(":");    json.append(objToJson(map.get(key)));    json.append(",");   }   json.setCharAt(json.length() - 1, '}');  } else {   json.append("}");  }  return json.toString(); } /**  * 将一个Set对象转换成Json数据格式返回  *   * @param set  *   需要进行转换的Set对象  * @return 转换后的Json数据格式字符串  */ private static String setToJson(Set<?> set) {  StringBuilder json = new StringBuilder();  json.append("[");  if (set != null && set.size() > 0) {   for (Object obj : set) {    json.append(objToJson(obj));    json.append(",");   }   json.setCharAt(json.length() - 1, ']');  } else {   json.append("]");  }  return json.toString(); } private static String stringToJson(String s) {  if (s == null) {   return "";  }  StringBuilder sb = new StringBuilder();  for (int i = 0; i < s.length(); i++) {   char ch = s.charAt(i);   switch (ch) {   case '"':    sb.append("///"");    break;   case '//':    sb.append("////");    break;   case '/b':    sb.append("//b");    break;   case '/f':    sb.append("//f");    break;   case '/n':    sb.append("//n");    break;   case '/r':    sb.append("//r");    break;   case '/t':    sb.append("//t");    break;   case '/':    sb.append("///");    break;   default:    if (ch >= '/u0000' && ch <= '/u001F') {     String ss = Integer.toHexString(ch);     sb.append("//u");     for (int k = 0; k < 4 - ss.length(); k++) {      sb.append('0');     }     sb.append(ss.toUpperCase());    } else {     sb.append(ch);    }   }  }  return sb.toString(); } public static String objToJson(Object obj) {  StringBuilder json = new StringBuilder();  if (obj == null) {   json.append("/"/"");  } else if (obj instanceof Number) {   Number num = (Number)obj;   json.append(num.toString());  } else if (obj instanceof Boolean) {   Boolean bl = (Boolean)obj;   json.append(bl.toString());  } else if (obj instanceof String) {   json.append("/"").append(stringToJson(obj.toString())).append("/"");  } else if (obj instanceof Object[]) {   json.append(arrayToJson((Object[]) obj));  } else if (obj instanceof List) {   json.append(listToJson((List) obj));  } else if (obj instanceof Map) {   json.append(mapToJson((Map) obj));  } else if (obj instanceof Set) {   json.append(setToJson((Set) obj));  } else {   json.append(beanToJson(obj));  }  return json.toString(); }  /**  * @Title: json2Map  * @Creater: chencc <br>  * @Date: 2011-3-28 <br>  * @Description: TODO转化json2map  * @param @param jsonString  * @param @return  * @return Map<String,Object>  * @throws  */ @SuppressWarnings("unchecked") public static Map<String, Object> json2Map(String jsonString) {    Map<String, Object> map = new HashMap<String, Object>();  try {   if(null != jsonString && !"".equals(jsonString)){    JSONObject jsonObject = new JSONObject(jsonString);       Iterator keyIter = jsonObject.keys();    String key = "";    Object value = null;       while (keyIter.hasNext()) {     key = (String) keyIter.next();     value = jsonObject.get(key);     map.put(key, value);    }   }  } catch (Exception e) {   e.printStackTrace();  }  return map; }  //测试方法 public static void main(String[] args) {  Map<String,Object> params = new HashMap<String,Object>();  params.put("callId123", Integer.valueOf(1000));  Map retMap = new HashMap();  retMap.put("params", params);  retMap.put("result", true);  List ls = new ArrayList();  ls.add(new HashMap());  ls.add("hello world!!");  ls.add(new String[4]);  retMap.put("list", ls);    String[] strArray = new String[10];  strArray[1]="first";  strArray[2]="2";  strArray[3]="3";  System.out.println("Boolean:"+JsonUtils.objToJson(true));  System.out.println("Number:"+JsonUtils.objToJson(23.3));  System.out.println("String:"+JsonUtils.objToJson("sdhfsjdgksdlkjfk/"sd,!#%$^&*#(*@&*%&*$fsdfsdfsdf"));  System.out.println("Map :"+JsonUtils.objToJson(retMap));  System.out.println("List:"+JsonUtils.objToJson(ls));  System.out.println("Array:"+JsonUtils.objToJson(strArray));    String json = JsonUtils.objToJson(retMap);  Map r = JsonUtils.json2Map(json);  System.out.println(r.get("callId123"));     }}

import java.io.IOException;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.HashMap;import java.util.LinkedHashMap;import java.util.List;import java.util.Map;import java.util.TimeZone;import net.sf.json.JSONArray;import net.sf.json.JSONObject;import net.sf.json.JsonConfig;import net.sf.json.util.CycleDetectionStrategy;import net.sf.json.util.PropertyFilter;import com.fasterxml.jackson.annotation.JsonInclude.Include;import com.fasterxml.jackson.databind.DeserializationFeature;import com.fasterxml.jackson.databind.ObjectMapper;public class JsonUtil {   private static ObjectMapper objectMapper = null; /**  * JSON初始化  */ static {  objectMapper = new ObjectMapper();   //设置为中国上海时区   objectMapper.setTimeZone(TimeZone.getTimeZone("GMT+8"));   //空值不序列化   objectMapper.setSerializationInclusion(Include.NON_NULL);   //反序列化时，属性不存在的兼容处理   objectMapper.getDeserializationConfig().withoutFeatures(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);   //序列化时，日期的统一格式   objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));   objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);    }    /**  * 把对象转换成为Json字符串  *  * @param obj  * @return  */ public static String convertObjectToJson(Object obj) {  if (obj == null) {//    throw new IllegalArgumentException("对象参数不能为空。");   return null;  }  try {   return objectMapper.writeValueAsString(obj);  } catch (IOException e) {   e.printStackTrace();  }  return null; } /**  * 把json字符串转成Object对象  * @param jsonString  * @return T  */ public static <T> T parseJsonToObject(String jsonString, Class<T> valueType) {    if(jsonString == null || "".equals((jsonString))){   return null;  }  try {   return objectMapper.readValue(jsonString, valueType);  } catch (Exception e) {   e.printStackTrace();  }  return null; } /**  * 把json字符串转成List对象  * @param jsonString  * @return List<T>  */ @SuppressWarnings("unchecked") public static <T> List<T> parseJsonToList(String jsonString,Class<T> valueType) {    if(jsonString == null || "".equals((jsonString))){   return null;  }    List<T> result = new ArrayList<T>();  try {   List<LinkedHashMap<Object, Object>> list = objectMapper.readValue(jsonString, List.class);      for (LinkedHashMap<Object, Object> map : list) {        String jsonStr = convertObjectToJson(map);        T t = parseJsonToObject(jsonStr, valueType);        result.add(t);   }  } catch (Exception e) {   e.printStackTrace();  }  return result; } /**  * JSON处理含有嵌套关系对象，避免出现异常：net.sf.json.JSONException: There is a cycle in the hierarchy的方法  * 注意：这样获得到的字符串中，引起嵌套循环的属性会置为null  *  * @param obj  * @return  */ public static JSONObject getJsonObject(Object obj) {  JsonConfig jsonConfig = new JsonConfig();  jsonConfig.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT);  jsonConfig.setJsonPropertyFilter(new PropertyFilter() {      @Override   public boolean apply(Object source, String name, Object value) {    if(value==null){     return true;    }    return false;   }  });  return JSONObject.fromObject(obj, jsonConfig); } /**  * JSON处理含有嵌套关系对象，避免出现异常：net.sf.json.JSONException: There is a cycle in the hierarchy的方法  * 注意：这样获得到的字符串中，引起嵌套循环的属性会置为null  *  * @param obj  * @return  */ public static JSONArray getJsonArray(Object obj) {  JsonConfig jsonConfig = new JsonConfig();  jsonConfig.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT);  return JSONArray.fromObject(obj, jsonConfig); } /**  * 解析JSON字符串成一个MAP  *  * @param jsonStr json字符串，格式如： {dictTable:"BM_XB",groupValue:"分组值"}  * @return  */ public static Map<String, Object> parseJsonStr(String jsonStr) {  Map<String, Object> result = new HashMap<String, Object>();  JSONObject jsonObj = JsonUtil.getJsonObject(jsonStr);  for (Object key : jsonObj.keySet()) {   result.put((String) key, jsonObj.get(key));  }  return result; }}