Reflect All : Field « Reflection « Java Tutorial

1. Java Tutorial
2. Reflection
3. Field

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

public class ReflectApp {
  public static void main(String args[]) {
    String parm = args[0];
    Class className = void.class;
    try {
      className = Class.forName(parm);
    } catch (ClassNotFoundException ex) {
      System.out.println("Not a class or interface.");
      System.exit(0);
    }
    describeClassOrInterface(className, parm);
  }

  static void describeClassOrInterface(Class className, String name) {
    displayModifiers(className.getModifiers());
    displayFields(className.getDeclaredFields());
    displayMethods(className.getDeclaredMethods());

    if (className.isInterface()) {
      System.out.println("Interface: " + name);
    } else {
      System.out.println("Class: " + name);
      displayInterfaces(className.getInterfaces());
      displayConstructors(className.getDeclaredConstructors());
    }
  }

  static void displayModifiers(int m) {
    System.out.println("Modifiers: " + Modifier.toString(m));
  }

  static void displayInterfaces(Class[] interfaces) {
    if (interfaces.length > 0) {
      System.out.println("Interfaces: ");
      for (int i = 0; i < interfaces.length; ++i)
        System.out.println(interfaces[i].getName());
    }
  }

  static void displayFields(Field[] fields) {
    if (fields.length > 0) {
      System.out.println("Fields: ");
      for (int i = 0; i < fields.length; ++i)
        System.out.println(fields[i].toString());
    }
  }

  static void displayConstructors(Constructor[] constructors) {
    if (constructors.length > 0) {
      System.out.println("Constructors: ");
      for (int i = 0; i < constructors.length; ++i)
        System.out.println(constructors[i].toString());
    }
  }

  static void displayMethods(Method[] methods) {
    if (methods.length > 0) {
      System.out.println("Methods: ");
      for (int i = 0; i < methods.length; ++i)
        System.out.println(methods[i].toString());
    }
  }
}