org.springframework.expression.common

Class LiteralExpression

  • java.lang.Object
    • org.springframework.expression.common.LiteralExpression
  • All Implemented Interfaces:
    Expression


    public class LiteralExpression
    extends java.lang.Object
    implements Expression
    A very simple hardcoded implementation of the Expression interface that represents a string literal. It is used with CompositeStringExpression when representing a template expression which is made up of pieces - some being real expressions to be handled by an EL implementation like SpEL, and some being just textual elements.
    Since:
    3.0
    Author:
    Andy Clement, Juergen Hoeller
    • Constructor Detail

      • LiteralExpression

        public LiteralExpression(java.lang.String literalValue)
    • Method Detail

      • getExpressionString

        public final java.lang.String getExpressionString()
        Description copied from interface: Expression
        Return the original string used to create this expression (unmodified).
        Specified by:
        getExpressionString in interface Expression
        Returns:
        the original expression string
      • getValue

        public java.lang.String getValue()
        Description copied from interface: Expression
        Evaluate this expression in the default standard context.
        Specified by:
        getValue in interface Expression
        Returns:
        the evaluation result
      • getValue

        @Nullable
        public <T> T getValue(@Nullable
                                        java.lang.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 java.lang.String getValue(java.lang.Object rootObject)
        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 to evaluate the expression
        Returns:
        the evaluation result
      • getValue

        @Nullable
        public <T> T getValue(java.lang.Object rootObject,
                                        @Nullable
                                        java.lang.Class<T> desiredResultType)
                                 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 to evaluate the expression
        desiredResultType - 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 java.lang.String getValue(EvaluationContext context)
        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
      • getValue

        @Nullable
        public <T> T getValue(EvaluationContext context,
                                        @Nullable
                                        java.lang.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 java.lang.String getValue(EvaluationContext context,
                                         java.lang.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 to evaluate the expression
        Returns:
        the evaluation result
        Throws:
        EvaluationException - if there is a problem during evaluation
      • getValue

        @Nullable
        public <T> T getValue(EvaluationContext context,
                                        java.lang.Object rootObject,
                                        @Nullable
                                        java.lang.Class<T> desiredResultType)
                                 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 to evaluate the expression
        desiredResultType - 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 java.lang.Class<?> getValueType(java.lang.Object rootObject)
                                        throws EvaluationException
        Description copied from interface: Expression
        Return the most general type that can be passed to the Expression.setValue(Object, 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 java.lang.Class<?> getValueType(EvaluationContext context,
                                               java.lang.Object rootObject)
                                        throws EvaluationException
        Description copied from interface: Expression
        Return the most general type that can be passed to the Expression.setValue(EvaluationContext, Object, 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
      • isWritable

        public boolean isWritable(java.lang.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; false otherwise
        Throws:
        EvaluationException - if there is a problem determining if it is writable
      • isWritable

        public boolean isWritable(EvaluationContext context)
        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; false otherwise
      • isWritable

        public boolean isWritable(EvaluationContext context,
                                  java.lang.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; false otherwise
        Throws:
        EvaluationException - if there is a problem determining if it is writable
      • setValue

        public void setValue(java.lang.Object rootObject,
                             @Nullable
                             java.lang.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,
                             java.lang.Object rootObject,
                             @Nullable
                             java.lang.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