org.apache.commons.jexl3.internal.introspection

## Class ConstructorMethod

- java.lang.Object
- - org.apache.commons.jexl3.internal.introspection.ConstructorMethod

- All Implemented Interfaces:
    JexlMethod

      public final class ConstructorMethod
      extends Object
      implements JexlMethod

  A JexlMethod that wraps a constructor.

- - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `static ConstructorMethod` | `discover(Introspector is, Object ctorHandle, Object... args)` Discovers a class constructor and wrap it as a JexlMethod.
    `Class<?>` | `getReturnType()` returns the return type of the method invoked.
    `Object` | `invoke(Object obj, Object... params)` Invocation method, called when the method invocation should be performed and a value returned.
    `boolean` | `isCacheable()` Specifies if this JexlMethod is cacheable and able to be reused for this class of object it was returned for.
    `boolean` | `tryFailed(Object rval)` Checks whether a tryInvoke return value indicates a failure or not.
    `Object` | `tryInvoke(String name, Object obj, Object... params)` Attempts to reuse this JexlMethod, checking that it is compatible with the actual set of arguments.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Method Detail

    - #### discover

          public static ConstructorMethod discover(Introspector is,
                                   Object ctorHandle,
                                   Object... args)

      Discovers a class constructor and wrap it as a JexlMethod.
      Parameters:
        `is` - the introspector
        `ctorHandle` - a class or class name
        `args` - constructor arguments
      Returns:
        a `JexlMethod`

    - #### invoke

          public Object invoke(Object obj,
                      Object... params)
                        throws Exception

      Description copied from interface: `JexlMethod`
      Invocation method, called when the method invocation should be performed and a value returned.
      Specified by:
        `invoke` in interface `JexlMethod`
      Parameters:
        `obj` - the object
        `params` - method parameters.
      Returns:
        the result
      Throws:
        `Exception` - on any error.

    - #### tryInvoke

          public Object tryInvoke(String name,
                         Object obj,
                         Object... params)

      Description copied from interface: `JexlMethod`
      Attempts to reuse this JexlMethod, checking that it is compatible with the actual set of arguments. Related to isCacheable since this method is often used with cached JexlMethod instances.
      Specified by:
        `tryInvoke` in interface `JexlMethod`
      Parameters:
        `name` - the method name
        `obj` - the object to invoke the method upon
        `params` - the method arguments
      Returns:
        the result of the method invocation that should be checked by tryFailed to determine if it succeeded or failed.

    - #### tryFailed

          public boolean tryFailed(Object rval)

      Description copied from interface: `JexlMethod`
      Checks whether a tryInvoke return value indicates a failure or not.

      Usage is : `Object r = tryInvoke(...); if (tryFailed(r) {...} else {...}`

      Specified by:
        `tryFailed` in interface `JexlMethod`
      Parameters:
        `rval` - the value returned by tryInvoke
      Returns:
        true if tryInvoke failed, false otherwise

    - #### isCacheable

          public boolean isCacheable()

      Description copied from interface: `JexlMethod`
      Specifies if this JexlMethod is cacheable and able to be reused for this class of object it was returned for.
      Specified by:
        `isCacheable` in interface `JexlMethod`
      Returns:
        true if can be reused for this class, false if not

    - #### getReturnType

          public Class<?> getReturnType()

      Description copied from interface: `JexlMethod`
      returns the return type of the method invoked.
      Specified by:
        `getReturnType` in interface `JexlMethod`
      Returns:
        return type

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