What is Reflection « Introduction « Reflection

The following application illustrates a simple use of the Java reflection capabilities.



import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

public class Main {
  public static void main(String args[]) {
    try {
      Class c = Class.forName("java.awt.Dimension");
      System.out.println("Constructors:");
      Constructor constructors[] = c.getConstructors();
      for (int i = 0; i < constructors.length; i++) {
        System.out.println(" " + constructors[i]);
      }
      System.out.println("Fields:");
      Field fields[] = c.getFields();
      for (int i = 0; i < fields.length; i++) {
        System.out.println(" " + fields[i]);
      }
      System.out.println("Methods:");
      Method methods[] = c.getMethods();
      for (int i = 0; i < methods.length; i++) {
        System.out.println(" " + methods[i]);
      }
    } catch (Exception e) {
      System.out.println("Exception: " + e);
    }
  }
}


Constructors:
 public java.awt.Dimension(java.awt.Dimension)
 public java.awt.Dimension(int,int)
 public java.awt.Dimension()
Fields:
 public int java.awt.Dimension.width
 public int java.awt.Dimension.height
Methods:
 public int java.awt.Dimension.hashCode()
 public boolean java.awt.Dimension.equals(java.lang.Object)
 public java.lang.String java.awt.Dimension.toString()
 public java.awt.Dimension java.awt.Dimension.getSize()
 public void java.awt.Dimension.setSize(int,int)
 public void java.awt.Dimension.setSize(double,double)
 public void java.awt.Dimension.setSize(java.awt.Dimension)
 public double java.awt.Dimension.getHeight()
 public double java.awt.Dimension.getWidth()
 public java.lang.Object java.awt.geom.Dimension2D.clone()
 public void java.awt.geom.Dimension2D.setSize(java.awt.geom.Dimension2D)
 public final native java.lang.Class java.lang.Object.getClass()
 public final void java.lang.Object.wait(long,int) throws java.lang.InterruptedException
 public final void java.lang.Object.wait() throws java.lang.InterruptedException
 public final native void java.lang.Object.wait(long) throws java.lang.InterruptedException
 public final native void java.lang.Object.notify()
 public final native void java.lang.Object.notifyAll()

Classes Defined in java.lang.reflect package

Class	Primary Function
AccessibleObject	Allows you to bypass the default access control checks.
Array	Allows you to dynamically create and manipulate arrays.
Constructor	Provides information about a constructor.
Field	Provides information about a field.
Method	Provides information about a method.
Modifier	Provides information about class and member access modifiers.
Proxy	Supports dynamic proxy classes.
ReflectPermission	Allows reflection of private or protected members of a class.