Object to JSON : JSON « Development « Android

1. Android
2. Development
3. JSON

Object to JSON

   
/*
 * Comet4J Copyright(c) 2011, http://code.google.com/p/comet4j/ This code is
 * licensed under BSD license. Use it as you wish, but keep this copyright
 * intact.
 */

//package org.comet4j.core.util;

import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * ????????json???,???????
 * @author xiaojinghai
 * @date 2011-7-18
 */

public class JSONUtil {

  public static String object2json(Object obj) {
    StringBuilder json = new StringBuilder();
    if (obj == null) {
      json.append("\"\"");
    } else if (obj instanceof String || obj instanceof Integer || obj instanceof Float || obj instanceof Boolean
        || obj instanceof Short || obj instanceof Double || obj instanceof Long || obj instanceof BigDecimal
        || obj instanceof BigInteger || obj instanceof Byte) {
      json.append("\"").append(string2json(obj.toString())).append("\"");
    } else if (obj instanceof Object[]) {
      json.append(array2json((Object[]) obj));
    } else if (obj instanceof List) {
      json.append(list2json((List<?>) obj));
    } else if (obj instanceof Map) {
      json.append(map2json((Map<?, ?>) obj));
    } else if (obj instanceof Set) {
      json.append(set2json((Set<?>) obj));
    } 
    return json.toString();
  }

  public static String list2json(List<?> list) {
    StringBuilder json = new StringBuilder();
    json.append("[");
    if (list != null && list.size() > 0) {
      for (Object obj : list) {
        json.append(object2json(obj));
        json.append(",");
      }
      json.setCharAt(json.length() - 1, ']');
    } else {
      json.append("]");
    }
    return json.toString();
  }

  public static String array2json(Object[] array) {
    StringBuilder json = new StringBuilder();
    json.append("[");
    if (array != null && array.length > 0) {
      for (Object obj : array) {
        json.append(object2json(obj));
        json.append(",");
      }
      json.setCharAt(json.length() - 1, ']');
    } else {
      json.append("]");
    }
    return json.toString();
  }

  public static String map2json(Map<?, ?> map) {
    StringBuilder json = new StringBuilder();
    json.append("{");
    if (map != null && map.size() > 0) {
      for (Object key : map.keySet()) {
        json.append(object2json(key));
        json.append(":");
        json.append(object2json(map.get(key)));
        json.append(",");
      }
      json.setCharAt(json.length() - 1, '}');
    } else {
      json.append("}");
    }
    return json.toString();
  }

  public static String set2json(Set<?> set) {
    StringBuilder json = new StringBuilder();
    json.append("[");
    if (set != null && set.size() > 0) {
      for (Object obj : set) {
        json.append(object2json(obj));
        json.append(",");
      }
      json.setCharAt(json.length() - 1, ']');
    } else {
      json.append("]");
    }
    return json.toString();
  }

  public static String string2json(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();
  }
}

   
    
    
  

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