值转为String，用于内部转换中需要使用String中转的情况<br>
转换规则为：

<pre>
1、字符串类型将被强转
2、数组将被转换为逗号分隔的字符串
3、其它类型将调用默认的toString()方法
</pre>

@param value 值
@return String
335695
protected String convertToStr(Object value) {
		if (null == value) {
			return null;
		}
		if (value instanceof CharSequence) {
			return value.toString();
		} else if (ArrayUtil.isArray(value)) {
			return ArrayUtil.toString(value);
		} else if(CharUtil.isChar(value)) {
			//对于ASCII字符使用缓存加速转换，减少空间创建
			return CharUtil.toString((char)value);
		}
		return value.toString();
	}
461696
public static function toString($value)
    {
        if (is_null($value)) {
            $ret = 'null';
        } elseif (is_bool($value)) {
            $ret = $value ? 'true' : 'false';
        } elseif (is_array($value)) {
            $ret = '[' . implode(',', $value) . ']';
        } else if ((!is_object($value) && settype($value, 'string') !== false)
            || (is_object($value) && method_exists($value, '__toString'))
        ) {
            $ret = '' . $value;
        } else {
            $ret = '[no string representation]';
        }

        return $ret;
    }
195758
public static String serialize(Object value) {
        if (value instanceof String) {
            return (String) value;
        } else if (value instanceof byte[]) {
            return new String((byte[]) value);
        }
1157138
public static function toString($value)
    {
        if($value == null)
        {
            return null;
        }
        $reflection = new \ReflectionClass(static::class);
        $values = $reflection->getConstants();

        //Check if input value is valid
        if(static::isValid($value, $reflection))
        {
            $constName = array_search($value, $values);
            return static::WordifyConst($constName);
        }
        else
        {
            return null;
        }
    }
846704
public static String encodeString(String value) {
    if (value == null) {
      return null;
    }
    StringBuilder encoded = new StringBuilder();
    int len = value.length();
    for (int i = 0; i < len; i++) {
      char c = value.charAt(i);
      switch (c) {
        case ARRAY_DELIMITER_CHAR:
        case KEY_VALUE_DELIMITER_CHAR:
        case ESCAPE_CHAR:
          encoded.append(ESCAPE_CHAR);
          break;
        default:
          // just append char
      }
      encoded.append(c);
    }
    return encoded.toString();
  }
533285
public static String getString(JSONValue value) {
        if (value == null)
            return null;
        if (!(value instanceof JSONString))
            throw new JSONException(NOT_A_STRING);
        return ((JSONString)value).toString();
    }
295842
public static String toCamelCase(final String value) {
        if (value == null || value.length() == 0) {
            return "";
        }
        String str = toStudlyCase(value);
        return str.substring(0, 1).toLowerCase() + str.substring(1);
    }
671216
public static String toStr(Object value, String defaultValue) {
		return convert(String.class, value, defaultValue);
	}
1337129
public static String encode(String value) {
		if(value==null) return null;

		StringBuilder encoded=null;
		int len=value.length();
		for(int c=0;c<len;c++) {
			char ch=value.charAt(c);
			if(
				(ch<' ' && ch!='\n' && ch!='\r')
				|| ch=='\\'
			) {
				if(encoded==null) {
					encoded=new StringBuilder();
					if(c>0) encoded.append(value, 0, c);
				}
				if(ch=='\\') encoded.append("\\\\");
				else if(ch=='\b') encoded.append("\\b");
				else if(ch=='\f') encoded.append("\\f");
				else if(ch=='\t') encoded.append("\\t");
				else {
					int ich=ch;
					encoded
						.append("\\u")
						.append(hexChars[(ich>>>12)&15])
						.append(hexChars[(ich>>>8)&15])
						.append(hexChars[(ich>>>4)&15])
						.append(hexChars[ich&15])
					;
				}
			} else {
				if(encoded!=null) encoded.append(ch);
			}
		}
		return encoded==null ? value : encoded.toString();
	}
1360681
@Override
    public String getString(Object value) {
        try {
            return DATE_TIME_FORMAT.format(value);
        } catch (IllegalArgumentException ignore) {
            // There's not much that can be done.
        }
        return StringValues.TO_STRING.getString(value);
    }
188124
private String escapeString(String value)
   {
      m_buffer.setLength(0);
      m_buffer.append('"');
      for (int index = 0; index < value.length(); index++)
      {
         char c = value.charAt(index);
         switch (c)
         {
            case '"':
            {
               m_buffer.append("\\\"");
               break;
            }

            case '\\':
            {
               m_buffer.append("\\\\");
               break;
            }

            case '/':
            {
               m_buffer.append("\\/");
               break;
            }

            case '\b':
            {
               m_buffer.append("\\b");
               break;
            }

            case '\f':
            {
               m_buffer.append("\\f");
               break;
            }

            case '\n':
            {
               m_buffer.append("\\n");
               break;
            }

            case '\r':
            {
               m_buffer.append("\\r");
               break;
            }

            case '\t':
            {
               m_buffer.append("\\t");
               break;
            }

            default:
            {
               // Append if it's not a control character (0x00 to 0x1f)
               if (c > 0x1f)
               {
                  m_buffer.append(c);
               }
               break;
            }
         }
      }
      m_buffer.append('"');
      return m_buffer.toString();
   }
314701
@Override
    public String handle(final Object value) {
        final StringBuilder s = new StringBuilder();
        if (value instanceof List) {
            final List<?> l = (List<?>) value;
            for (final Object o : l) {
                if (s.length() > 0) {
                    s.append(',');
                }
                s.append(o.toString());
            }
        } else {
            s.append(value);
        }
        return s.toString();
    }
1089457
public static String toJsonString(Object value) {
        if (value == null) {
            return "null";
        }
        else if (value.getClass().equals(String.class)) {
            return "\"" + StringUtils.jsonEncoding(value.toString()) + "\"";
        }
        // else it's a RawJson, Boolean or Number so no escaping or quotes
        else {
            return value.toString();
        }
    }
771778
public String asString(Object value) {

        if (value == null) {
            return "";
        }

        if (!this.isArray(value)) {
            return String.valueOf(value);
        }

        Object[] array = this.asArray(value);

        StringBuilder builder = new StringBuilder();

        for (Object obj : array) {
            builder.append(this.asString(obj));
        }

        return builder.toString();
    }
1322648
public static String print(final Object value) {
        if (value == null) {
            return "null";
        }
        if (value instanceof String) {
            return '"' + value.toString() + '"';
        }
        if (value instanceof Character) {
            return printChar((Character) value);
        }
        if (value instanceof Long) {
            return value + "L";
        }
        if (value instanceof Double) {
            return value + "d";
        }
        if (value instanceof Float) {
            return value + "f";
        }
        if (value instanceof Short) {
            return "(short) " + value;
        }
        if (value instanceof Byte) {
            return String.format("(byte) 0x%02X", (Byte) value);
        }
        if (value instanceof Map) {
            return printMap((Map<?, ?>) value);
        }
        if (value.getClass().isArray()) {
            return printValues("[", ", ", "]", new Iterator<Object>() {
                private int currentIndex = 0;

                public boolean hasNext() {
                    return currentIndex < Array.getLength(value);
                }

                public Object next() {
                    return Array.get(value, currentIndex++);
                }

                public void remove() {
                    throw new UnsupportedOperationException("cannot remove items from an array");
                }
            });
        }
        if (value instanceof FormattedText) {
            return (((FormattedText) value).getText());
        }

        return descriptionOf(value);
    }
767238
public static String typeValueString(final Object value) {
        StringBuilder sb = new StringBuilder(valueString(value));
        return sb.append(" :").append(typeString(value)).toString();
    }
1334540
public static String[] split(String value) {
        if (value == null || "".equals(value)) {
            return EMPTY_STRING_ARRAY;
        }
        int len = value.length();
        List<String> list = new LinkedList<>();
        boolean collectingSpace = true;
        int start = 0;
        for (int i = 0; i < len; i++) {
            char c = value.charAt(i);
            if (c == ' ' || c == '\t' || c == '\n' || c == '\r') {
                if (!collectingSpace) {
                    list.add(value.substring(start, i));
                    collectingSpace = true;
                }
            } else {
                if (collectingSpace) {
                    start = i;
                    collectingSpace = false;
                }
            }
        }
        if (start < len) {
            int end = len;
            for (int i = 1; len > i; i++) {
                char c = value.charAt(len - i);
                if (c == ' ' || c == '\t' || c == '\n' || c == '\r') {
                    end--;
                    continue;
                }
                break;
            }
            list.add(value.substring(start, end));
        }
        return list.toArray(EMPTY_STRING_ARRAY);
    }