Package javax.el

Class ValueExpression

java.lang.Object
javax.el.Expression
javax.el.ValueExpression
All Implemented Interfaces:
Serializable
public abstract class ValueExpression extends Expression
See Also:

  • Constructor Details

    • ValueExpression

      public ValueExpression()

  • Method Details

    • getValue

      public abstract Object getValue(ELContext context)
      Parameters:
      context - The EL context for this evaluation
      Returns:
      The result of evaluating this value expression
      Throws:
      NullPointerException - If the supplied context is null
      PropertyNotFoundException - If a property/variable resolution failed because no match was found or a match was found but was not readable
      ELException - Wraps any exception throw whilst resolving a property or variable

    • setValue

      public abstract void setValue(ELContext context, Object value)
      Parameters:
      context - The EL context for this evaluation
      value - The value to set the property to which this value expression refers
      Throws:
      NullPointerException - If the supplied context is null
      PropertyNotFoundException - If a property/variable resolution failed because no match was found
      PropertyNotWritableException - If a property/variable resolution failed because a match was found but was not writable
      ELException - Wraps any exception throw whilst resolving a property or variable

    • isReadOnly

      public abstract boolean isReadOnly(ELContext context)
      Parameters:
      context - The EL context for this evaluation
      Returns:
      true if this expression is read only otherwise false
      Throws:
      NullPointerException - If the supplied context is null
      PropertyNotFoundException - If a property/variable resolution failed because no match was found or a match was found but was not readable
      ELException - Wraps any exception throw whilst resolving a property or variable

    • getType

      public abstract Class<?> getType(ELContext context)
      Parameters:
      context - The EL context for this evaluation
      Returns:
      The type of the result of this value expression
      Throws:
      NullPointerException - If the supplied context is null
      PropertyNotFoundException - If a property/variable resolution failed because no match was found or a match was found but was not readable
      ELException - Wraps any exception throw whilst resolving a property or variable

    • getExpectedType

      public abstract Class<?> getExpectedType()

    • getValueReference

      public ValueReference getValueReference(ELContext context)
      Parameters:
      context - The EL context for this evaluation
      Returns:
      This default implementation always returns null
      Since:
      EL 2.2