import java.lang.reflect.*;
import java.util.*;

/* An example of an encapsulation checker. It checks that all nonstatic fields of a class 
 * are private and can be accessed by public get methods.
 */
  
class EncCheck {
	StringBuffer errorLog = new StringBuffer(); // Empty if no errors.
	Class clazz; 								// the class we are currently checking
	List<Field> nonStaticFields; 				// null, or a list of all non-static fields

	// precondition: clazz != null	 
	public void findAllNonStaticFields(){
		Field[] fields = clazz.getDeclaredFields();
		nonStaticFields = new ArrayList<Field>();
		for (Field f : fields){
			int modifiers = f.getModifiers();
			if (! Modifier.isStatic(modifiers) )
				nonStaticFields.add(f);
		}
	}

	public void ensurePrivate() {
		for ( Field f : nonStaticFields){
			int modifiers = f.getModifiers();
			if (! Modifier.isPrivate(modifiers) )
				errorLog.append
					(f.toString() + " is not private\n");
		}
	}

	private static final Class[] noParameters = new Class[0];

	public void ensureGetters(){
		for ( Field f : nonStaticFields){
			try{
				clazz.getMethod(getter(f), noParameters);
			}catch(NoSuchMethodException ex){
				errorLog.append
					(f.toString() + " has no accessor\n");
			}
		}
	}

	private String getter (Field f){
		String name = f.getName();
		String first = name.substring(0,0).toUpperCase();
		String rest = name.substring(1,name.length());
		return "get"+ first + rest;
	}

	public void check(Class c) throws Exception {
		clazz = c;
		findAllNonStaticFields();
		ensurePrivate();
		ensureGetters();
		//… do the check
		if (errorLog.length() > 0 )
			System.out.println(errorLog.toString());
		else
			System.out.println("No errors");
	}

	public static void main(String[] args) throws Exception {
		String className = args[0];
		Class c = Class.forName(className);
		EncCheck checker = new EncCheck();
		checker.check(c);
	}
}