DefaultExpressionEvaluator (Flink : 2.0-SNAPSHOT API)

java.lang.Object
- org.apache.flink.table.runtime.functions.DefaultExpressionEvaluator

All Implemented Interfaces:

Serializable, SpecializedFunction.ExpressionEvaluator
```
@Internal
public class DefaultExpressionEvaluator
extends Object
implements SpecializedFunction.ExpressionEvaluator
```
Default runtime implementation for SpecializedFunction.ExpressionEvaluator.

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor	Description
`DefaultExpressionEvaluator(GeneratedFunction<RichFunction> generatedClass, Class<?> returnClass, Class<?>[] argClasses, String expressionSummary)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Closes the runtime implementation for expression evaluation.
`MethodHandle`	`open(FunctionContext context)`	Creates and initializes runtime implementation for expression evaluation.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - DefaultExpressionEvaluator
```
public DefaultExpressionEvaluator(GeneratedFunction<RichFunction> generatedClass,
                                  Class<?> returnClass,
                                  Class<?>[] argClasses,
                                  String expressionSummary)
```
- Method Detail
  - open
```
public MethodHandle open(FunctionContext context)
```
    Description copied from interface: SpecializedFunction.ExpressionEvaluator
    
    Creates and initializes runtime implementation for expression evaluation. The returned MethodHandle should be stored in a transient variable and can be invoked via MethodHandle.invokeExact(Object...) using the conversion classes previously defined via the passed DataTypes.
    This method should be called in UserDefinedFunction.open(FunctionContext).
    
    Specified by:
    
    open in interface SpecializedFunction.ExpressionEvaluator
  - close
```
public void close()
```
    Description copied from interface: SpecializedFunction.ExpressionEvaluator
    
    Closes the runtime implementation for expression evaluation. It performs clean up work.
    This method should be called in UserDefinedFunction.close().
    
    Specified by:
    
    close in interface SpecializedFunction.ExpressionEvaluator
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object