Reflection: Find the data type
Sunday, July 26th, 2009from types import *
def what (x):
if type(x) == IntType:
print "This is an int."
else:
print "This is something else."
what(4)
what("4")
from types import *
def what (x):
if type(x) == IntType:
print "This is an int."
else:
print "This is something else."
what(4)
what("4")
using System.Reflection;
using System.Windows.Forms;
[assembly: AssemblyTitle("title")]
[assembly: AssemblyDescription("code.")]
[assembly: AssemblyConfiguration("Retail")]
[assembly: AssemblyCompany("Inc.")]
[assembly: AssemblyProduct("C#")]
[assembly: AssemblyCopyright("Inc.")]
[assembly: AssemblyVersion("1.0.*")]
public class SimpleHelloWorld : Form
{
public static void Main()
{
Application.Run(new SimpleHelloWorld());
}
public SimpleHelloWorld()
{
Text = "Hello, WindowsForms!";
}
}
/*
* file: VariousMethodDemos.java
* package: oreilly.hcj.reflection
*
* This software is granted under the terms of the Common Public License,
* CPL, which may be found at the following URL:
* http://www-124.ibm.com/developerworks/oss/CPLv1.0.htm
*
* Copyright(c) 2003-2005 by the authors indicated in the @author tags.
* All Rights are Reserved by the various authors.
*
########## DO NOT EDIT ABOVE THIS LINE ########## */
import java.lang.reflect.Method;
/**
* Demonstration of various method invocation issues.
*
* @author <a href=mailto:kraythe@arcor.de>Robert Simmons jr. (kraythe)</a>
* @version $Revision$
*/
public class VariousMethodDemos {
/**
* Run the demo.
*
* @param args
* Command line arguments (ignored).
*/
public static void main(final String[] args) {
try {
final Class[] ARG_TYPES = new Class[] { String.class };
Object result = null;
Method meth = Integer.class.getMethod("parseInt", ARG_TYPES);
result = meth.invoke(null, new Object[] { new String("44") });
System.out.println(result);
result = meth.invoke(null, new Object[] { new String("Jonny") });
System.out.println(result);
} catch (final Exception ex) {
ex.printStackTrace();
}
}
}
/* ########## End of File ########## */
/* From http://java.sun.com/docs/books/tutorial/index.html */
/*
* Copyright (c) 1995-1998 Sun Microsystems, Inc. All Rights Reserved.
*
* Permission to use, copy, modify, and distribute this software and its
* documentation for NON-COMMERCIAL purposes and without fee is hereby granted
* provided that this copyright notice appears in all copies. Please refer to
* the file "copyright.html" for further important copyright and licensing
* information.
*
* SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
* SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
* WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
* NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY
* LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES.
*/
import java.awt.Rectangle;
import java.lang.reflect.Field;
public class SampleSet {
public static void main(String[] args) {
Rectangle r = new Rectangle(100, 20);
System.out.println("original: " + r.toString());
modifyWidth(r, new Integer(300));
System.out.println("modified: " + r.toString());
}
static void modifyWidth(Rectangle r, Integer widthParam) {
Field widthField;
Integer widthValue;
Class c = r.getClass();
try {
widthField = c.getField("width");
widthField.set(r, widthParam);
} catch (NoSuchFieldException e) {
System.out.println(e);
} catch (IllegalAccessException e) {
System.out.println(e);
}
}
}
/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Sun Microsystems nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.lang.reflect.Field;
import java.util.List;
public class FieldSpy<T> {
public boolean[][] b = { { false, false }, { true, true } };
public String name = "Alice";
public List<Integer> list;
public T val;
public static void main(String… args) {
try {
Class<?> c = Class.forName("FieldSpy");
Field f = c.getField("name");
System.out.format("Type: %s%n", f.getType());
System.out.format("GenericType: %s%n", f.getGenericType());
// production code should handle these exceptions more gracefully
} catch (ClassNotFoundException x) {
x.printStackTrace();
} catch (NoSuchFieldException x) {
x.printStackTrace();
}
}
}