This class shows using Reflection to get a field from another class : Class « Reflection « Java

Home
Java
1.2D Graphics GUI
2.3D
3.Advanced Graphics
4.Ant
5.Apache Common
6.Chart
7.Class
8.Collections Data Structure
9.Data Type
10.Database SQL JDBC
11.Design Pattern
12.Development Class
13.EJB3
14.Email
15.Event
16.File Input Output
17.Game
18.Generics
19.GWT
20.Hibernate
21.I18N
22.J2EE
23.J2ME
24.JDK 6
25.JNDI LDAP
26.JPA
27.JSP
28.JSTL
29.Language Basics
30.Network Protocol
31.PDF RTF
32.Reflection
33.Regular Expressions
34.Scripting
35.Security
36.Servlets
37.Spring
38.Swing Components
39.Swing JFC
40.SWT JFace Eclipse
41.Threads
42.Tiny Application
43.Velocity
44.Web Services SOA
45.XML
Java » Reflection » ClassScreenshots 
This class shows using Reflection to get a field from another class
This class shows using Reflection to get a field from another class
         
/*
 * Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
 * All rights reserved. Software written by Ian F. Darwin and others.
 * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 
 * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee
 * cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's,
 * pioneering role in inventing and promulgating (and standardizing) the Java 
 * language and environment is gratefully acknowledged.
 
 * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
 * inventing predecessor languages C and C++ is also gratefully acknowledged.
 */

import java.lang.reflect.Field;
import java.util.Calendar;

/** This class shows using Reflection to get a field from another class. */
public class FindField {

  public static void main(String[] unusedthrows NoSuchFieldException,
      IllegalAccessException {

    // Create instance of FindField
    FindField gf = new FindField();

    // Create instance of target class (YearHolder defined below).
    Object o = new YearHolder();

    // Use gf to extract a field from o.
    System.out.println("The value of 'currentYear' is: "
        + gf.intFieldValue(o, "currentYear"));
  }

  int intFieldValue(Object o, String namethrows NoSuchFieldException,
      IllegalAccessException {
    Class c = o.getClass();
    Field fld = c.getField(name);
    int value = fld.getInt(o);
    return value;
  }
}

/** This is just a class that we want to get a field from */

class YearHolder {
  /** Just a field that is used to show getting a field's value. */
  public int currentYear = Calendar.getInstance().get(Calendar.YEAR);
}

           
         
    
    
    
    
    
    
    
    
  
Related examples in the same category
1.Class Reflection: class modifierClass Reflection: class modifier
2.Class Reflection: class nameClass Reflection: class name
3.Class Reflection: name for super classClass Reflection: name for super class
4.Object Reflection: create new instance
5.Class reflectionClass reflection
6.Show the class keyword and getClass() method in actionShow the class keyword and getClass() method in action
7.Simple Demonstration of a ClassLoader WILL NOT COMPILE OUT OF THE BOX
8.Demonstrate classFor to create an instance of an object
9.CrossRef prints a cross-reference about all classes named in argv
10.Make up a compilable version of a given Sun or other API
11.Show a couple of things you can do with a Class object
12.Reflect1 shows the information about the class named in argv
13.Show that you can, in fact, take the class of a primitive
14.JavaP prints structural information about classes
15.Provides a set of static methods that extend the Java metaobject
16.Demonstration of speed of reflexive versus programmatic invocation
17.Use reflection to get console char set
18.Load the class source location from Class.getResource()
19.Access the enclosing class from an inner class
20.Use reflection to dynamically discover the capabilities of a class.
21.Get the class By way of a string
22.Get the class By way of .class
23.Return a String representation of an object's overall identity
24.Manipulate Java class files in strange and mysterious ways
25.Class file reader for obtaining the parameter names for declared methods in a class
26.Convert a given String into the appropriate Class.
27.Manipulate Java classes
28.Encapsulates a class serialVersionUID and codebase.
29.Dump a class using Reflection
30.This program uses reflection to spy on objects
31.This program uses reflection to print all features of a classThis program uses reflection to print all features of a class
32.Get Unqualified Name
33.Return a paranthesis enclosed, comma sepearated String of all SimpleClass names in params.
34.Adds the class SimpleNames, comma sepearated and surrounded by paranthesis to the call StringBuffer
35.Class Finder
java2s.com  | Contact Us | Privacy Policy
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.