java.beans

Class Statement

Known Direct Subclasses:
Expression

public class Statement
extends Object

A Statement captures the execution of an object method. It stores the object, the method to call, and the arguments to the method and provides the ability to execute the method on the object, using the provided arguments.
Since:
1.4

Constructor Summary

Statement(Object target, String methodName, Object[] arguments)
Constructs a statement representing the invocation of object.methodName(arg[0], arg[1], ...);

If the argument array is null it is replaced with an array of zero length.

Method Summary

void
execute()
Execute the statement.
Object[]
getArguments()
Return the statement arguments.
String
getMethodName()
Return the statement method name.
Object
getTarget()
Return the statement object.
String
toString()
Returns a string representation of this Statement.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Statement

public Statement(Object target,
                 String methodName,
                 Object[] arguments)
Constructs a statement representing the invocation of object.methodName(arg[0], arg[1], ...);

If the argument array is null it is replaced with an array of zero length.

Parameters:
target - The object to invoke the method on.
methodName - The object method to invoke.
arguments - An array of arguments to pass to the method.

Method Details

execute

public void execute()
            throws Exception
Execute the statement.

Finds the specified method in the target object and calls it with the arguments given in the constructor.

The most specific method according to the JLS(15.11) is used when there are multiple methods with the same name.

Execute performs some special handling for methods and parameters:

  • Static methods can be executed by providing the class as a target.
  • The method name new is reserved to call the constructor new() will construct an object and return it. Not useful unless an expression :-)
  • If the target is an array, get and set as defined in java.util.List are recognized as valid methods and mapped to the methods of the same name in java.lang.reflect.Array.
  • The native datatype wrappers Boolean, Byte, Character, Double, Float, Integer, Long, and Short will map to methods that have native datatypes as parameters, in the same way as Method.invoke. However, these wrappers also select methods that actually take the wrapper type as an argument.

The Sun spec doesn't deal with overloading between int and Integer carefully. If there are two methods, one that takes an Integer and the other taking an int, the method chosen is not specified, and can depend on the order in which the methods are declared in the source file.

Throws:
Exception - if an exception occurs while locating or invoking the method.

getArguments

public Object[] getArguments()
Return the statement arguments.

getMethodName

public String getMethodName()
Return the statement method name.

getTarget

public Object getTarget()
Return the statement object.

toString

public String toString()
Returns a string representation of this Statement.
Overrides:
toString in interface Object
Returns:
A string representation of this Statement.

Statement.java Copyright (C) 2004, 2005, 2006, Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.