java第8天代碼（集合類）-list

2019-11-17 04:05:32

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/************Student.java begin***************/

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

public class Student {
PRivate String name;
private String passWord;
public String getName() {
  return name;
}
public String getPassword() {
  return password;
}
public void setName(String name) {
  this.name = name;
}
public void setPassword(String password) {
  this.password = password;
}
public Student(String name, String password) {
  super();
  this.name = name;
  this.password = password;
}
public Student(){}

public List show(String name,String password){

  ArrayList list=new ArrayList();

  return list;
}

@Override
public String toString() {
  // TODO Auto-generated method stub
  return "name= "+name+"  password= "+password;
}
public static void main(String args[]){

   List list=new ArrayList();

//向list中添加對象
   list.add(new Student("xsxs","xsxs"));
   list.add(new Student("mingkun","ambow"));
   list.add(new Student("frfr","frfr"));
   list.add(new Student("bgbg","frfr"));
   list.add(new Student("cdcd","cdcd"));

   // Iterator  這個是迭代器
   Iterator it=list.iterator();
   while(it.hasNext()){
    System.out.println(it.next());
   }

}
}

/************Student.java end***************/

/************TestArrayList.java begin***************/

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

public class TestArrayList {

public static void main(String args[]){
  List list=new ArrayList();
  list.add(new Integer(43));
  list.add(54);
  list.add(32);
  list.add(76);
  list.add(31);
  list.add(89);

  //索引指定查詢
//  System.out.println(list.get(0));

//  for(int i=0;i<7;i++){
//   System.out.println(list.get(i));
//  }

//  for(int i=0;i<list.size();i++){
//   System.out.println(list.get(i));
//  }

  //判斷數組中對象是否存在contains(),返回時boolean
//  System.out.println(list.contains("hyhy"));

  //迭代器Iterator（迭代集合中所有的對象）
  Iterator it=list.iterator();
  while(it.hasNext()){
   System.out.println(it.next());
  }

  Collections.sort(list);
  System.out.println("****************");
  Iterator it1=list.iterator();
  while(it1.hasNext()){
   System.out.println(it1.next());
  }
}
}

/************TestArrayList.java end***************/

/************Person.java begin***************/

import java.util.ArrayList;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Collections;

public class Person implements Comparable{

private String name;

private int age;

public String getName() {
  return name;
}

public int getAge() {
  return age;
}

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

public void setAge(int age) {
  this.age = age;
}

public Person(String name, int age) {
  super();
  this.name = name;
  this.age = age;
}

public  Person(){}

public String toString(){
  return "name="+name+"  age=" +age;
}
public void printList(List list){
  Iterator i=list.iterator();
  while(i.hasNext()){
   System.out.println(i.next());
  }
}

public int compareTo(Object obj) {

/**

*這里面堆對象的age進行比較產生序列

*/
  if(obj instanceof Person){
   Person p=(Person) obj;
//   return this.age-p.getAge();
   return p.getAge()-this.age;
  }
  return 0;
}
public static void main(String args[]){
  Person p=new Person();
  TestPerson tp=new TestPerson();
  List list=new ArrayList();
  list.add(new Person("大一",25));
  list.add(new Person("張三",24));
  list.add(new Person("王二",22));
  list.add(new Person("李四",27));
  p.printList(list);
  Collections.sort(list,tp);
  System.out.println("*************");
  p.printList(list);
}

}

class TestPerson implements Comparator{

public int compare(Object o1, Object o2) {
  // TODO Auto-generated method stub
  if(o1 instanceof Person && o2 instanceof Person){
   Person p=(Person) o1;
   Person p1=(Person) o2;
   return p.getAge()-p1.getAge();
//   return p1.getAge()-p.getAge();
  }
  return 0;
}

}

/************Person.java end***************/

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