TestDao.java

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

/**
 * 
 * @author Leon
 * 
 * @param <T>
 */
public class TestDao<T> {
	
	
	public List<T> list(RowMapper<T> mapper) {
		List<T> list = new ArrayList<T>();
		list.add(mapper.map());
		return list;
	}

	public static void main(String[] args) {
		// TestDao<String> dao = new TestDao<String>();
		//
		// List<String> tList = dao.list(new RowMapper<String>() {
		// @Override
		// public String map() {
		// return "abc";
		// }
		// });

		// System.out.println(tList);

		TestDao<User> dao = new TestDao<User>();
		List<User> tList = dao.list(new RowMapper<User>() {

			@Override
			public User map() {
				return new User();
			}

		});
		
		System.out.println(tList);
	}
}

interface RowMapper<T> {
	T map();
}

class User {

	private String name = "admin";

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	@Override
	public String toString() {
		return "User [name=" + name + "]";
	}

}

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

/**

• @author Leon

• @param
  */
  //比原有方法少了个
  public class TestDao{

  //比原有方法多了个
  public List list(RowMapper mapper) {
  List list = new ArrayList();
  list.add(mapper.map());
  return list;
  }

  public static void main(String[] args) {
  // TestDao dao = new TestDao();
  //
  // List tList = dao.list(new RowMapper() {
  // @OverRide
  // public String map() {
  // return "abc";
  // }
  // });

  // System.out.println(tList);
  
  TestDao dao = new TestDao();
  List<User> tList = dao.list(new RowMapper<User>() {
  
      @Override
      public User map() {
          return new User();
      }
  
  });
  
  System.out.println(tList);
  

  }
  }

interface RowMapper {
T map();
}

class User {

private String name = "admin";

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

@Override
public String toString() {
    return "User [name=" + name + "]";
}

}