ReflectionTest.java

package reflection;

import java.util.*;
import java.util.jar.Attributes.Name;
import java.lang.reflect.*;

public class ReflectionTest {

	public static void main(String[] args){
		
		String name;
		if (args.length > 0) name = args[0];
		else{
			Scanner in = new Scanner(System.in);
			System.out.println("Enter class name (e.g. java.util.Date): ");
			name = in.next();
		}
		
		try{
			Class cl = Class.forName(name);
			Class supercl = cl.getSuperclass();
			String modifiers = Modifier.toString(cl.getModifiers());
			if (modifiers.length() > 0) System.out.println(modifiers + " ");
			System.out.println("class " + name);
			if (supercl != null && supercl != Object.class) System.out.println("extends:" + supercl.getName());
			
			System.out.print("\n{\n");
			printConstructors(cl);
			System.out.println(" ");
			printMethods(cl);
			System.out.println(" ");
			printFields(cl);
			System.out.println(" ");
			System.out.println("}");
		
		
		}
		catch (ClassNotFoundException e){
			e.printStackTrace();
		}
		System.exit(0);
	}
	public static void printConstructors(Class cl){
		Constructor[] constructors = cl.getDeclaredConstructors();
		for(Constructor c : constructors){
			String name = c.getName();
			System.out.print(" ");
			String modifiers = Modifier.toString(c.getModifiers());
			if (modifiers.length() > 0) System.out.print(modifiers + " ");
			System.out.print(name + "(");
			
			Class[] paramTypes = c.getParameterTypes();
			for(int j = 0; j < paramTypes.length; ++j){
				if (j > 0) System.out.print(", ");
				System.out.print(paramTypes[j].getName());
			}
			System.out.println(");");
		}
	}
	public static void printMethods(Class cl){
		Method[] methods = cl.getDeclaredMethods();
		for (Method m : methods){
			Class retType = m.getReturnType();
			String name = m.getName();
			
			System.out.print(" ");
			String modifiers = Modifier.toString(m.getModifiers());
			if (modifiers.length() > 0) System.out.print(modifiers + " ");
			System.out.print(retType.getName() + " " + name + "(");
			
			Class[] paramTypes = m.getParameterTypes();
			for (int j = 0; j < paramTypes.length; j++){
				if (j > 0) System.out.print(", ");
				System.out.print(paramTypes[j].getName());
			}
			System.out.println(");");
		}
	}
	public static void printFields(Class cl){
		Field[] fields = cl.getDeclaredFields();
		
		for (Field f : fields){
			Class type = f.getType();
			String name = f.getName();
			System.out.print(" ");
			String modifiers = Modifier.toString(f.getModifiers());
			if (modifiers.length() > 0) System.out.println(modifiers + " ");
			System.out.println(type.getName() + " " + name + ";");
		}
	}
}