Package org.flowable.common.engine.impl.de.odysseus.el

Class TreeMethodExpression

java.lang.Object
org.flowable.common.engine.impl.javax.el.Expression
org.flowable.common.engine.impl.javax.el.MethodExpression
org.flowable.common.engine.impl.de.odysseus.el.TreeMethodExpression
All Implemented Interfaces:
Serializable
public final class TreeMethodExpression extends MethodExpression
A method expression is ready to be evaluated (by calling either invoke(ELContext, Object[]) or getMethodInfo(ELContext)). Instances of this class are usually created using an ExpressionFactoryImpl.
Author:
Christoph Beck
See Also:

  • Constructor Details

    • TreeMethodExpression

      public TreeMethodExpression(TreeStore store, FunctionMapper functions, VariableMapper variables, TypeConverter converter, String expr, Class<?> returnType, Class<?>[] paramTypes)
      Create a new method expression. The expression must be an lvalue expression or literal text. The expected return type may be null, meaning "don't care". If it is an lvalue expression, the parameter types must not be null. If it is literal text, the expected return type must not be void.
      Parameters:
      store - used to get the parse tree from.
      functions - the function mapper used to bind functions
      variables - the variable mapper used to bind variables
      expr - the expression string
      returnType - the expected return type (may be null)
      paramTypes - the expected parameter types (must not be null for lvalues)

  • Method Details

    • getMethodInfo

      public MethodInfo getMethodInfo(ELContext context) throws ELException
      Evaluates the expression and answers information about the method
      Specified by:
      getMethodInfo in class MethodExpression
      Parameters:
      context - used to resolve properties (base.property and base[property])
      Returns:
      method information or null for literal expressions
      Throws:
      ELException - if evaluation fails (e.g. suitable method not found)

    • getExpressionString

      public String getExpressionString()
      Description copied from class: Expression
      Returns the original String used to create this Expression, unmodified. This is used for debugging purposes but also for the purposes of comparison (e.g. to ensure the expression in a configuration file has not changed). This method does not provide sufficient information to re-create an expression. Two different expressions can have exactly the same expression string but different function mappings. Serialization should be used to save and restore the state of an Expression.
      Specified by:
      getExpressionString in class Expression
      Returns:
      The original expression String.

    • invoke

      public Object invoke(ELContext context, Object[] paramValues) throws ELException
      Evaluates the expression and invokes the method.
      Specified by:
      invoke in class MethodExpression
      Parameters:
      context - used to resolve properties (base.property and base[property])
      paramValues -
      Returns:
      method result or null if this is a literal text expression
      Throws:
      ELException - if evaluation fails (e.g. suitable method not found)

    • isLiteralText

      public boolean isLiteralText()
      Description copied from class: Expression
      Returns whether this expression was created from only literal text. This method must return true if and only if the expression string this expression was created from contained no unescaped EL delimiters (${...} or #{...}).
      Specified by:
      isLiteralText in class Expression
      Returns:
      true if this is a literal text expression

    • isParmetersProvided

      public boolean isParmetersProvided()
      Description copied from class: MethodExpression
      Return whether this MethodExpression was created with parameters.

      This method must return true if and only if parameters are specified in the EL, using the expr-a.expr-b(...) syntax.

      Overrides:
      isParmetersProvided in class MethodExpression
      Returns:
      true if this is a method invocation expression

    • isDeferred

      public boolean isDeferred()
      Answer true if this is a deferred expression (starting with #{)

    • equals

      public boolean equals(Object obj)
      Expressions are compared using the concept of a structural id: variable and function names are anonymized such that two expressions with same tree structure will also have the same structural id and vice versa. Two method expressions are equal if
      1. their builders are equal
      2. their structural id's are equal
      3. their bindings are equal
      4. their expected types match
      5. their parameter types are equal
      Specified by:
      equals in class Expression
      Parameters:
      obj - the Object to test for equality.
      Returns:
      true if obj equals this Expression; false otherwise.

    • hashCode

      public int hashCode()
      Description copied from class: Expression
      Returns the hash code for this Expression. See the note in the Expression.equals(Object) method on how two expressions can be equal if their expression Strings are different. Recall that if two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result. Implementations must take special note and implement hashCode correctly.
      Specified by:
      hashCode in class Expression
      Returns:
      The hash code for this Expression.
      See Also:

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • dump

      public void dump(PrintWriter writer)
      Print the parse tree.
      Parameters:
      writer -