ValueConstants (Spring Framework 4.3.30.RELEASE API)

```
public interface ValueConstants
```
Common value constants shared between bind annotations.
从以下版本开始:
3.0.1
作者:
Juergen Hoeller

- 字段概要
  字段
  修饰符和类型字段说明
  static String DEFAULT_NONE
  Constant defining a value for no default - as a replacement for null which we cannot use in annotation attributes.

- 字段详细资料
  - DEFAULT_NONE
```
static final String DEFAULT_NONE
```
    Constant defining a value for no default - as a replacement for null which we cannot use in annotation attributes.
    This is an artificial arrangement of 16 unicode characters, with its sole purpose being to never match user-declared values.
    另请参阅:
    RequestParam.defaultValue(), RequestHeader.defaultValue(), CookieValue.defaultValue(), 常量字段值