SpelExpression (Spring Framework 3.2.6.RELEASE API)

java.lang.Object
- org.springframework.expression.spel.standard.SpelExpression

All Implemented Interfaces:

Expression
```
public class SpelExpression
extends Object
implements Expression
```
A SpelExpression represents a parsed (valid) expression that is ready to be evaluated in a specified context. An expression can be evaluated standalone or in a specified context. During expression evaluation the context may be asked to resolve references to types, beans, properties, and methods.

Since:

3.0

Author:

Andy Clement

Constructor Summary

Constructors
Constructor and Description
`SpelExpression(String expression, SpelNodeImpl ast, SpelParserConfiguration configuration)` Construct an expression, only used by the parser.

Method Summary

Methods
Modifier and Type	Method and Description
`SpelNode`	`getAST()`
`EvaluationContext`	`getEvaluationContext()` Return the default evaluation context that will be used if none is supplied on an evaluation call
`String`	`getExpressionString()` Returns the original string used to create this expression, unmodified.
`Object`	`getValue()` Evaluate this expression in the default standard context.
`<T> T`	`getValue(Class<T> expectedResultType)` Evaluate the expression in the default context.
`Object`	`getValue(EvaluationContext context)` Evaluate this expression in the provided context and return the result of evaluation.
`<T> T`	`getValue(EvaluationContext context, Class<T> expectedResultType)` Evaluate the expression in a specified context which can resolve references to properties, methods, types, etc - the type of the evaluation result is expected to be of a particular class and an exception will be thrown if it is not and cannot be converted to that type.
`Object`	`getValue(EvaluationContext context, Object rootObject)` Evaluate this expression in the provided context and return the result of evaluation, but use the supplied root context as an override for any default root object specified in the context.
`<T> T`	`getValue(EvaluationContext context, Object rootObject, Class<T> expectedResultType)` Evaluate the expression in a specified context which can resolve references to properties, methods, types, etc - the type of the evaluation result is expected to be of a particular class and an exception will be thrown if it is not and cannot be converted to that type.
`Object`	`getValue(Object rootObject)` Evaluate this expression against the specified root object
`<T> T`	`getValue(Object rootObject, Class<T> expectedResultType)` Evaluate the expression in the default context against the specified root object.
`Class<?>`	`getValueType()` Returns the most general type that can be passed to the `Expression.setValue(EvaluationContext, Object)` method using the default context.
`Class<?>`	`getValueType(EvaluationContext context)` Returns the most general type that can be passed to the `Expression.setValue(EvaluationContext, Object)` method for the given context.
`Class<?>`	`getValueType(EvaluationContext context, Object rootObject)` Returns the most general type that can be passed to the `Expression.setValue(EvaluationContext, Object)` method for the given context.
`Class<?>`	`getValueType(Object rootObject)` Returns the most general type that can be passed to the `Expression.setValue(EvaluationContext, Object)` method using the default context.
`TypeDescriptor`	`getValueTypeDescriptor()` Returns the most general type that can be passed to the `Expression.setValue(EvaluationContext, Object)` method using the default context.
`TypeDescriptor`	`getValueTypeDescriptor(EvaluationContext context)` Returns the most general type that can be passed to the `Expression.setValue(EvaluationContext, Object)` method for the given context.
`TypeDescriptor`	`getValueTypeDescriptor(EvaluationContext context, Object rootObject)` Returns the most general type that can be passed to the `Expression.setValue(EvaluationContext, Object)` method for the given context.
`TypeDescriptor`	`getValueTypeDescriptor(Object rootObject)` Returns the most general type that can be passed to the `Expression.setValue(EvaluationContext, Object)` method using the default context.
`boolean`	`isWritable(EvaluationContext context)` Determine if an expression can be written to, i.e.
`boolean`	`isWritable(EvaluationContext context, Object rootObject)` Determine if an expression can be written to, i.e.
`boolean`	`isWritable(Object rootObject)` Determine if an expression can be written to, i.e.
`void`	`setEvaluationContext(EvaluationContext context)` Set the evaluation context that will be used if none is specified on an evaluation call.
`void`	`setValue(EvaluationContext context, Object value)` Set this expression in the provided context to the value provided.
`void`	`setValue(EvaluationContext context, Object rootObject, Object value)` Set this expression in the provided context to the value provided.
`void`	`setValue(Object rootObject, Object value)` Set this expression in the provided context to the value provided.
`String`	`toStringAST()` Produce a string representation of the Abstract Syntax Tree for the expression, this should ideally look like the input expression, but properly formatted since any unnecessary whitespace will have been discarded during the parse of the expression.

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

- Constructor Detail
  - SpelExpression
```
public SpelExpression(String expression,
              SpelNodeImpl ast,
              SpelParserConfiguration configuration)
```
    Construct an expression, only used by the parser.
- Method Detail
  - getValue
```
public Object getValue()
                throws EvaluationException
```
    Description copied from interface: Expression
    
    Evaluate this expression in the default standard context.
    
    Specified by:
    
    getValue in interface Expression
    
    Returns:
    the evaluation result
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - getValue
```
public Object getValue(Object rootObject)
                throws EvaluationException
```
    Description copied from interface: Expression
    
    Evaluate this expression against the specified root object
    
    Specified by:
    
    getValue in interface Expression
    
    Parameters:
    rootObject - the root object against which properties/etc will be resolved
    
    Returns:
    the evaluation result
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - getValue
```
public <T> T getValue(Class<T> expectedResultType)
           throws EvaluationException
```
    Description copied from interface: Expression
    
    Evaluate the expression in the default context. If the result of the evaluation does not match (and cannot be converted to) the expected result type then an exception will be returned.
    
    Specified by:
    
    getValue in interface Expression
    
    Parameters:
    expectedResultType - the class the caller would like the result to be
    
    Returns:
    the evaluation result
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - getValue
```
public <T> T getValue(Object rootObject,
             Class<T> expectedResultType)
           throws EvaluationException
```
    Description copied from interface: Expression
    
    Evaluate the expression in the default context against the specified root object. If the result of the evaluation does not match (and cannot be converted to) the expected result type then an exception will be returned.
    
    Specified by:
    
    getValue in interface Expression
    
    Parameters:
    rootObject - the root object against which properties/etc will be resolved
    expectedResultType - the class the caller would like the result to be
    
    Returns:
    the evaluation result
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - getValue
```
public Object getValue(EvaluationContext context)
                throws EvaluationException
```
    Description copied from interface: Expression
    
    Evaluate this expression in the provided context and return the result of evaluation.
    
    Specified by:
    
    getValue in interface Expression
    
    Parameters:
    context - the context in which to evaluate the expression
    
    Returns:
    the evaluation result
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - getValue
```
public Object getValue(EvaluationContext context,
              Object rootObject)
                throws EvaluationException
```
    Description copied from interface: Expression
    
    Evaluate this expression in the provided context and return the result of evaluation, but use the supplied root context as an override for any default root object specified in the context.
    
    Specified by:
    
    getValue in interface Expression
    
    Parameters:
    context - the context in which to evaluate the expression
    rootObject - the root object against which properties/etc will be resolved
    
    Returns:
    the evaluation result
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - getValue
```
public <T> T getValue(EvaluationContext context,
             Class<T> expectedResultType)
           throws EvaluationException
```
    Description copied from interface: Expression
    
    Evaluate the expression in a specified context which can resolve references to properties, methods, types, etc - the type of the evaluation result is expected to be of a particular class and an exception will be thrown if it is not and cannot be converted to that type.
    
    Specified by:
    
    getValue in interface Expression
    
    Parameters:
    context - the context in which to evaluate the expression
    expectedResultType - the class the caller would like the result to be
    
    Returns:
    the evaluation result
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - getValue
```
public <T> T getValue(EvaluationContext context,
             Object rootObject,
             Class<T> expectedResultType)
           throws EvaluationException
```
    Description copied from interface: Expression
    
    Evaluate the expression in a specified context which can resolve references to properties, methods, types, etc - the type of the evaluation result is expected to be of a particular class and an exception will be thrown if it is not and cannot be converted to that type. The supplied root object overrides any default specified on the supplied context.
    
    Specified by:
    
    getValue in interface Expression
    
    Parameters:
    context - the context in which to evaluate the expression
    rootObject - the root object against which properties/etc will be resolved
    expectedResultType - the class the caller would like the result to be
    
    Returns:
    the evaluation result
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - getValueType
```
public Class<?> getValueType()
                      throws EvaluationException
```
    Description copied from interface: Expression
    
    Returns the most general type that can be passed to the Expression.setValue(EvaluationContext, Object) method using the default context.
    
    Specified by:
    
    getValueType in interface Expression
    
    Returns:
    the most general type of value that can be set on this context
    
    Throws:
    
    EvaluationException - if there is a problem determining the type
  - getValueType
```
public Class<?> getValueType(Object rootObject)
                      throws EvaluationException
```
    Description copied from interface: Expression
    
    Returns the most general type that can be passed to the Expression.setValue(EvaluationContext, Object) method using the default context.
    
    Specified by:
    
    getValueType in interface Expression
    
    Parameters:
    rootObject - the root object against which to evaluate the expression
    
    Returns:
    the most general type of value that can be set on this context
    
    Throws:
    
    EvaluationException - if there is a problem determining the type
  - getValueType
```
public Class<?> getValueType(EvaluationContext context)
                      throws EvaluationException
```
    Description copied from interface: Expression
    
    Returns the most general type that can be passed to the Expression.setValue(EvaluationContext, Object) method for the given context.
    
    Specified by:
    
    getValueType in interface Expression
    
    Parameters:
    context - the context in which to evaluate the expression
    
    Returns:
    the most general type of value that can be set on this context
    
    Throws:
    
    EvaluationException - if there is a problem determining the type
  - getValueType
```
public Class<?> getValueType(EvaluationContext context,
                    Object rootObject)
                      throws EvaluationException
```
    Description copied from interface: Expression
    
    Returns the most general type that can be passed to the Expression.setValue(EvaluationContext, Object) method for the given context. The supplied root object overrides any specified in the context.
    
    Specified by:
    
    getValueType in interface Expression
    
    Parameters:
    context - the context in which to evaluate the expression
    rootObject - the root object against which to evaluate the expression
    
    Returns:
    the most general type of value that can be set on this context
    
    Throws:
    
    EvaluationException - if there is a problem determining the type
  - getValueTypeDescriptor
```
public TypeDescriptor getValueTypeDescriptor()
                                      throws EvaluationException
```
    Description copied from interface: Expression
    
    Returns the most general type that can be passed to the Expression.setValue(EvaluationContext, Object) method using the default context.
    
    Specified by:
    
    getValueTypeDescriptor in interface Expression
    
    Returns:
    a type descriptor for the most general type of value that can be set on this context
    
    Throws:
    
    EvaluationException - if there is a problem determining the type
  - getValueTypeDescriptor
```
public TypeDescriptor getValueTypeDescriptor(Object rootObject)
                                      throws EvaluationException
```
    Description copied from interface: Expression
    
    Returns the most general type that can be passed to the Expression.setValue(EvaluationContext, Object) method using the default context.
    
    Specified by:
    
    getValueTypeDescriptor in interface Expression
    
    Parameters:
    rootObject - the root object against which to evaluate the expression
    
    Returns:
    a type descriptor for the most general type of value that can be set on this context
    
    Throws:
    
    EvaluationException - if there is a problem determining the type
  - getValueTypeDescriptor
```
public TypeDescriptor getValueTypeDescriptor(EvaluationContext context)
                                      throws EvaluationException
```
    Description copied from interface: Expression
    
    Returns the most general type that can be passed to the Expression.setValue(EvaluationContext, Object) method for the given context.
    
    Specified by:
    
    getValueTypeDescriptor in interface Expression
    
    Parameters:
    context - the context in which to evaluate the expression
    
    Returns:
    a type descriptor for the most general type of value that can be set on this context
    
    Throws:
    
    EvaluationException - if there is a problem determining the type
  - getValueTypeDescriptor
```
public TypeDescriptor getValueTypeDescriptor(EvaluationContext context,
                                    Object rootObject)
                                      throws EvaluationException
```
    Description copied from interface: Expression
    
    Returns the most general type that can be passed to the Expression.setValue(EvaluationContext, Object) method for the given context. The supplied root object overrides any specified in the context.
    
    Specified by:
    
    getValueTypeDescriptor in interface Expression
    
    Parameters:
    context - the context in which to evaluate the expression
    rootObject - the root object against which to evaluate the expression
    
    Returns:
    a type descriptor for the most general type of value that can be set on this context
    
    Throws:
    
    EvaluationException - if there is a problem determining the type
  - getExpressionString
```
public String getExpressionString()
```
    Description copied from interface: Expression
    
    Returns the original string used to create this expression, unmodified.
    
    Specified by:
    
    getExpressionString in interface Expression
    
    Returns:
    the original expression string
  - isWritable
```
public boolean isWritable(EvaluationContext context)
                   throws EvaluationException
```
    Description copied from interface: Expression
    
    Determine if an expression can be written to, i.e. setValue() can be called.
    
    Specified by:
    
    isWritable in interface Expression
    
    Parameters:
    context - the context in which the expression should be checked
    
    Returns:
    true if the expression is writable
    
    Throws:
    
    EvaluationException - if there is a problem determining if it is writable
  - isWritable
```
public boolean isWritable(Object rootObject)
                   throws EvaluationException
```
    Description copied from interface: Expression
    
    Determine if an expression can be written to, i.e. setValue() can be called.
    
    Specified by:
    
    isWritable in interface Expression
    
    Parameters:
    rootObject - the root object against which to evaluate the expression
    
    Returns:
    true if the expression is writable
    
    Throws:
    
    EvaluationException - if there is a problem determining if it is writable
  - isWritable
```
public boolean isWritable(EvaluationContext context,
                 Object rootObject)
                   throws EvaluationException
```
    Description copied from interface: Expression
    
    Determine if an expression can be written to, i.e. setValue() can be called. The supplied root object overrides any specified in the context.
    
    Specified by:
    
    isWritable in interface Expression
    
    Parameters:
    context - the context in which the expression should be checked
    rootObject - the root object against which to evaluate the expression
    
    Returns:
    true if the expression is writable
    
    Throws:
    
    EvaluationException - if there is a problem determining if it is writable
  - setValue
```
public void setValue(EvaluationContext context,
            Object value)
              throws EvaluationException
```
    Description copied from interface: Expression
    
    Set this expression in the provided context to the value provided.
    
    Specified by:
    
    setValue in interface Expression
    
    Parameters:
    context - the context in which to set the value of the expression
    value - the new value
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - setValue
```
public void setValue(Object rootObject,
            Object value)
              throws EvaluationException
```
    Description copied from interface: Expression
    
    Set this expression in the provided context to the value provided.
    
    Specified by:
    
    setValue in interface Expression
    
    Parameters:
    rootObject - the root object against which to evaluate the expression
    value - the new value
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - setValue
```
public void setValue(EvaluationContext context,
            Object rootObject,
            Object value)
              throws EvaluationException
```
    Description copied from interface: Expression
    
    Set this expression in the provided context to the value provided. The supplied root object overrides any specified in the context.
    
    Specified by:
    
    setValue in interface Expression
    
    Parameters:
    context - the context in which to set the value of the expression
    rootObject - the root object against which to evaluate the expression
    value - the new value
    
    Throws:
    
    EvaluationException - if there is a problem during evaluation
  - getAST
```
public SpelNode getAST()
```
    Returns:
    return the Abstract Syntax Tree for the expression
  - toStringAST
```
public String toStringAST()
```
    Produce a string representation of the Abstract Syntax Tree for the expression, this should ideally look like the input expression, but properly formatted since any unnecessary whitespace will have been discarded during the parse of the expression.
    
    Returns:
    the string representation of the AST
  - getEvaluationContext
```
public EvaluationContext getEvaluationContext()
```
    Return the default evaluation context that will be used if none is supplied on an evaluation call
    
    Returns:
    the default evaluation context
  - setEvaluationContext
```
public void setEvaluationContext(EvaluationContext context)
```
    Set the evaluation context that will be used if none is specified on an evaluation call.
    
    Parameters:
    context - an evaluation context

Class SpelExpression

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

SpelExpression

Method Detail

getValue

getValue

getValue

getValue

getValue

getValue

getValue

getValue

getValueType

getValueType

getValueType

getValueType

getValueTypeDescriptor

getValueTypeDescriptor

getValueTypeDescriptor

getValueTypeDescriptor

getExpressionString

isWritable

isWritable

isWritable

setValue

setValue

setValue

getAST

toStringAST

getEvaluationContext

setEvaluationContext