ValueRef.NullValueRef (Spring Framework 4.3.30.RELEASE API)

java.lang.Object
- org.springframework.expression.spel.ast.ValueRef.NullValueRef

所有已实现的接口:
ValueRef
封闭接口:
ValueRef
```
public static class ValueRef.NullValueRef
extends Object
implements ValueRef
```
A ValueRef for the null value.

嵌套类概要
- 从接口继承的嵌套类/接口 org.springframework.expression.spel.ast.ValueRef
  ValueRef.NullValueRef, ValueRef.TypedValueHolderValueRef

构造器概要
构造器
构造器说明
NullValueRef()

方法概要

所有方法实例方法具体方法
修饰符和类型	方法	说明
`TypedValue`	`getValue()`	Returns the value this ValueRef points to, it should not require expression component re-evaluation.
`boolean`	`isWritable()`	Indicates whether calling setValue(Object) is supported.
`void`	`setValue(Object newValue)`	Sets the value this ValueRef points to, it should not require expression component re-evaluation.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - NullValueRef
```
public NullValueRef()
```
- 方法详细资料
  - getValue
```
public TypedValue getValue()
```
    从接口复制的说明: ValueRef
    Returns the value this ValueRef points to, it should not require expression component re-evaluation.
    指定者:
    getValue 在接口中 ValueRef
    返回:
    the value
  - setValue
```
public void setValue(Object newValue)
```
    从接口复制的说明: ValueRef
    Sets the value this ValueRef points to, it should not require expression component re-evaluation.
    指定者:
    setValue 在接口中 ValueRef
    参数:
    newValue - the new value
  - isWritable
```
public boolean isWritable()
```
    从接口复制的说明: ValueRef
    Indicates whether calling setValue(Object) is supported.
    指定者:
    isWritable 在接口中 ValueRef
    返回:
    true if setValue() is supported for this value reference.