org.apache.jasper.el
Class JspMethodExpression

java.lang.Object
  extended by javax.el.Expression
      extended by javax.el.MethodExpression
          extended by org.apache.jasper.el.JspMethodExpression
All Implemented Interfaces:
java.io.Externalizable, java.io.Serializable

public final class JspMethodExpression
extends javax.el.MethodExpression
implements java.io.Externalizable

See Also:
Serialized Form

Constructor Summary
JspMethodExpression()
           
JspMethodExpression(java.lang.String mark, javax.el.MethodExpression target)
           
 
Method Summary
 boolean equals(java.lang.Object obj)
          Determines whether the specified object is equal to this Expression.
 java.lang.String getExpressionString()
          Returns the original String used to create this Expression, unmodified.
 javax.el.MethodInfo getMethodInfo(javax.el.ELContext context)
          Evaluates the expression relative to the provided context, and returns information about the actual referenced method.
 int hashCode()
          Returns the hash code for this Expression.
 java.lang.Object invoke(javax.el.ELContext context, java.lang.Object[] params)
          If a String literal is specified as the expression, returns the String literal coerced to the expected return type of the method signature.
 boolean isLiteralText()
          Returns whether this expression was created from only literal text.
 void readExternal(java.io.ObjectInput in)
           
 void writeExternal(java.io.ObjectOutput out)
           
 
Methods inherited from class javax.el.MethodExpression
isParmetersProvided
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

JspMethodExpression

public JspMethodExpression()

JspMethodExpression

public JspMethodExpression(java.lang.String mark,
                           javax.el.MethodExpression target)
Method Detail

getMethodInfo

public javax.el.MethodInfo getMethodInfo(javax.el.ELContext context)
                                  throws java.lang.NullPointerException,
                                         javax.el.PropertyNotFoundException,
                                         javax.el.MethodNotFoundException,
                                         javax.el.ELException
Description copied from class: javax.el.MethodExpression
Evaluates the expression relative to the provided context, and returns information about the actual referenced method.

Specified by:
getMethodInfo in class javax.el.MethodExpression
Parameters:
context - The context of this evaluation
Returns:
an instance of MethodInfo containing information about the method the expression evaluated to.
Throws:
java.lang.NullPointerException - if context is null
javax.el.PropertyNotFoundException - if one of the property resolutions failed because a specified variable or property does not exist or is not readable.
javax.el.MethodNotFoundException - if no suitable method can be found.
javax.el.ELException - if an exception was thrown while performing property or variable resolution. The thrown exception must be included as the cause property of this exception, if available.

invoke

public java.lang.Object invoke(javax.el.ELContext context,
                               java.lang.Object[] params)
                        throws java.lang.NullPointerException,
                               javax.el.PropertyNotFoundException,
                               javax.el.MethodNotFoundException,
                               javax.el.ELException
Description copied from class: javax.el.MethodExpression
If a String literal is specified as the expression, returns the String literal coerced to the expected return type of the method signature. An ELException is thrown if expectedReturnType is void or if the coercion of the String literal to the expectedReturnType yields an error (see Section "1.18 Type Conversion" of the EL specification). If not a String literal, evaluates the expression relative to the provided context, invokes the method that was found using the supplied parameters, and returns the result of the method invocation. Any parameters passed to this method is ignored if isLiteralText() or isParametersProvided() is true.

Specified by:
invoke in class javax.el.MethodExpression
Parameters:
context - The context of this evaluation.
params - The parameters to pass to the method, or null if no parameters.
Returns:
the result of the method invocation (null if the method has a void return type).
Throws:
java.lang.NullPointerException - if context is null
javax.el.PropertyNotFoundException - if one of the property resolutions failed because a specified variable or property does not exist or is not readable.
javax.el.MethodNotFoundException - if no suitable method can be found.
javax.el.ELException - if a String literal is specified and expectedReturnType of the MethodExpression is void or if the coercion of the String literal to the expectedReturnType yields an error (see Section "1.18 Type Conversion").

equals

public boolean equals(java.lang.Object obj)
Description copied from class: javax.el.Expression
Determines whether the specified object is equal to this Expression.

The result is true if and only if the argument is not null, is an Expression object that is the of the same type (ValueExpression or MethodExpression), and has an identical parsed representation.

Note that two expressions can be equal if their expression Strings are different. For example, ${fn1:foo()} and ${fn2:foo()} are equal if their corresponding FunctionMappers mapped fn1:foo and fn2:foo to the same method.

Specified by:
equals in class javax.el.Expression
Parameters:
obj - the Object to test for equality.
Returns:
true if obj equals this Expression; false otherwise.
See Also:
Hashtable, Object.equals(java.lang.Object)

hashCode

public int hashCode()
Description copied from class: javax.el.Expression
Returns the hash code for this Expression.

See the note in the Expression.equals(java.lang.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 javax.el.Expression
Returns:
The hash code for this Expression.
See Also:
Expression.equals(java.lang.Object), Hashtable, Object.hashCode()

getExpressionString

public java.lang.String getExpressionString()
Description copied from class: javax.el.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 javax.el.Expression
Returns:
The original expression String.

isLiteralText

public boolean isLiteralText()
Description copied from class: javax.el.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 delimeters (${...} or #{...}).

Specified by:
isLiteralText in class javax.el.Expression
Returns:
true if this expression was created from only literal text; false otherwise.

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException
Specified by:
writeExternal in interface java.io.Externalizable
Throws:
java.io.IOException

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException
Specified by:
readExternal in interface java.io.Externalizable
Throws:
java.io.IOException
java.lang.ClassNotFoundException


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