反射によるlistのソート汎用は、すべてのエンティティタイプをサポートします.

public class SortUtils<T>{
	
	public void sort(List<T> list,String keyName,final String sortname) throws Exception{
		Set<String> idset = new HashSet<String>();
		for(T t:list){
			 Method method = t.getClass().getMethod(keyName);
			 System.out.println(method.invoke(t));
			 idset.add((String)method.invoke(t));
		}
// 
		Collections.sort(list, new Comparator<T>() {
			@Override
			public int compare(T o1, T o2) {
				Method method1;
				try {
					method1 = o1.getClass().getMethod(sortname);
					Method method2 = o2.getClass().getMethod(sortname);
					String name1 = (String)method1.invoke(o1);
					String name2 = (String)method2.invoke(o2);
					return name1.compareTo(name2);
				} catch (Exception e) {
					e.printStackTrace();
					return 0;
				} 
			}
			
		});
	}

}

public class User {
private String id;
private String name;
public String getId() {
	return id;
}
public void setId(String id) {
	this.id = id;
}
public String getName() {
	return name;
}
public void setName(String name) {
	this.name = name;
}


}

import java.util.ArrayList;
import java.util.List;


public class Test {
public static void main(String[] args) throws Exception {
	SortUtils<User> usersort = new SortUtils<User>();
	List<User> list = new ArrayList<User>();
	for(int i=5;i>0;i--){
		User user =new User();
		user.setId(String.valueOf(i));
		user.setName(String.valueOf(i)+"name");
		list.add(user);
	}
	usersort.sort(list,"getId","getId");
	for(User user:list){
		System.out.println(user.getId());
	}
}
}