CachedExpressionEvaluator (Spring Framework 5.2.12.RELEASE API)

java.lang.Object
- org.springframework.context.expression.CachedExpressionEvaluator

```
public abstract class CachedExpressionEvaluator
extends Object
```
Shared utility class used to evaluate and cache SpEL expressions that are defined on AnnotatedElement.
从以下版本开始:
4.2
作者:
Stephane Nicoll
另请参阅:
AnnotatedElementKey

嵌套类概要
嵌套类
修饰符和类型类说明
protected static class CachedExpressionEvaluator.ExpressionKey
An expression key.

构造器概要

构造器
限定符	构造器	说明
`protected`	`CachedExpressionEvaluator()`	Create a new instance with a default `SpelExpressionParser`.
`protected`	`CachedExpressionEvaluator(SpelExpressionParser parser)`	Create a new instance with the specified `SpelExpressionParser`.

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
`protected Expression`	`getExpression(Map<CachedExpressionEvaluator.ExpressionKey,Expression> cache, AnnotatedElementKey elementKey, String expression)`	Return the `Expression` for the specified SpEL value
`protected ParameterNameDiscoverer`	`getParameterNameDiscoverer()`	Return a shared parameter name discoverer which caches data internally.
`protected SpelExpressionParser`	`getParser()`	Return the `SpelExpressionParser` to use.

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
  - CachedExpressionEvaluator
```
protected CachedExpressionEvaluator(SpelExpressionParser parser)
```
    Create a new instance with the specified SpelExpressionParser.
  - CachedExpressionEvaluator
```
protected CachedExpressionEvaluator()
```
    Create a new instance with a default SpelExpressionParser.
- 方法详细资料
  - getParser
```
protected SpelExpressionParser getParser()
```
    Return the SpelExpressionParser to use.
  - getParameterNameDiscoverer
```
protected ParameterNameDiscoverer getParameterNameDiscoverer()
```
    Return a shared parameter name discoverer which caches data internally.
    从以下版本开始:
    4.3
  - getExpression
```
protected Expression getExpression(Map<CachedExpressionEvaluator.ExpressionKey,Expression> cache,
                                   AnnotatedElementKey elementKey,
                                   String expression)
```
    Return the Expression for the specified SpEL value
    Parse the expression if it hasn't been already.
    参数:
    cache - the cache to use
    elementKey - the element on which the expression is defined
    expression - the expression to parse