[20160725]MyComparableTest

知识点：

1、Collections的使用。

2、自定义类泛型的使用。

3、自定义类，toString();equals();hashCode()方法的重写。

 import java.util.*;

 public class MyComparableTest{
   public static void main(String[] args) {
     List<Name> a=new LinkedList<Name>();
     a.add(new Name("shang","zeng"));
     a.add(new Name("qi","li"));
     a.add(new Name("mei","niang"));
     a.add(new Name("peingfei","chen"));

     System.out.println(a);
     Collections.sort(a);
     System.out.println(a);

     System.out.println(a.remove(new Name("peingfei","chen")));
     System.out.println(a);

   }
 }

 class Name implements Comparable<Name>{
   String firstname,lastname;

   public Name(String firstname,String lastname){
     this.firstname=firstname;
     this.lastname=lastname;
   }

     public String toString(){
      return(firstname+" "+lastname);
   }

 /* //equals()method one
   public boolean equals(Object obj){
     if (obj==null){  return false;  }
     else
        { if(obj instanceof Name)
              {
                Name n = (Name)obj;
                if (this.firstname.equals(n.firstname) && this.lastname.equals(n.lastname)){return true;}
              }

         return false;
        }
   }
 */
   // equals()methoed two
 public boolean equals(Object obj){
    if(obj instanceof Name){
      Name n=(Name)obj;
      return (this.firstname.equals(n.firstname))
          && (this.lastname.equals(n.lastname));
    }

     return super.equals(obj);
 }

   public int hashCode(){  return firstname.hashCode();  }

    public int compareTo(Name o){
      int lastnamecompare=lastname.compareTo(o.lastname);
      return
          (lastnamecompare!=0?lastnamecompare:firstname.compareTo(o.firstname));
    }
 }