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Java Tutorial » Reflection » Class  
7.1.9.Demonstrates how to set public field objectsPrevious/Next
/*
 *     file: HiddenFieldModification.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.Field;

/**
 * Demonstrates how to set public field objects.
 
 @author <a href=mailto:kraythe@arcor.de>Robert Simmons jr. (kraythe)</a>
 @version $Revision: 1.3 $
 */
public class HiddenFieldModification {
  /**
   * Sets all int fields in an object to 0.
   
   @param obj
   *          The object to operate on.
   
   @throws RuntimeException
   *           If there is a reflection problem.
   */
  public static void initIntFields(final Object obj) {
    try {
      Field[] fields = obj.getClass().getDeclaredFields();
      for (int idx = 0; idx < fields.length; idx++) {
        if (fields[idx].getType() == int.class) {
          fields[idx].setAccessible(true);
          fields[idx].setInt(obj, 0);
        }
      }
    catch (final IllegalAccessException ex) {
      throw new RuntimeException(ex);
    }
  }

  /**
   * Demo Method.
   
   @param args
   *          Command line arguments.
   */
  public static final void main(final String[] args) {
    Integer value = new Integer("123");
    System.out.println("Before: " + value);
    initIntFields(value);
    System.out.println("After: " + value);
  }
}

/* ########## End of File ########## */
7.1.Class
7.1.1. Get class name for various object
7.1.2. Create new instance
7.1.3. Get Canonical Name for a class
7.1.4. Demonstrates the use of getDeclaringClass()
7.1.5. Demonstrates the use of instance comparisons
7.1.6. Demonstrates usage of various class information methods
7.1.7. Demonstrates how to get declaration information on a Class
7.1.8. Demonstrates Dynamic class type checking
7.1.9. Demonstrates how to set public field objects
7.1.10. Demonstrates fetching nested class info from a Class object
7.1.11. Demonstration of how to obtain instances of java.lang.Class
7.1.12. Demonstrates getting immediate superclass info
7.1.13. Get declared method by name and parameter type
7.1.14. get class from an object
7.1.15. Returns the name of a class without the package name
7.1.16. Class comparator: compare and sort classes and their superclasses.
7.1.17. Is Type Compatible
7.1.18. Is the Same Signature
7.1.19. Determine whether the supplied string represents a well-formed fully-qualified Java classname.