1~5 cbdba
6~10 bbbda
二、
1.File（String pathname）、File（URI uri）
2.FileInputStream.read()==null
3.前者是無序不可重復，後者是有序可重復
4.equals(Object obj)、toString（）方法
5.java.lang
6.null!=in.read()
*7. Long、Byte、java.lang
8.in.read(a)!=0、out.write(a);
9.ArrayList、HashSet、Map
10.interrupt()
11.
12.Integer.parseInt("12");
13.a.toString()、a+""
14.a.getBytes()
15.new String(b);
三、
1.
//Person.java
package com.ldxx.test;
public class Person
{
private String name;
private int age;
private String sex;
public Person(String name, int age, String sex)
{
this.name = name;
this.age = age;
this.sex = sex;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getSex()
{
return sex;
}
public void setSex(String sex)
{
this.sex = sex;
}
@Override
public String toString()
{
return "name:"+this.getName()+"age:"+this.getAge()+"sex:"+this.getSex();
}
}
//PersonUtils.java 邏輯處理類
package com.ldxx.test;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
public class PersonUtils implements Comparator<Person>
{
// 實現排序的方法
@Override
public int compare(Person p1, Person p2)
{
if (p1.getAge() > p2.getAge())
{
return 1;
}
if (p1.getAge() < p2.getAge())
{
return -1;
}
return 0;
}
// 打印性別是男的方法
public void printMan(HashSet<Person> hs)
{
Iterator<Person> pit = hs.iterator();
while (pit.hasNext())
{
Person pe = pit.next();
if ("男".equals(pe.getSex()))
{
System.out.println(pe.toString());
}
}
}
//把HashSet轉換成List
public List<Person> hashSetToList(HashSet<Person> hs)
{
List<Person> list = new ArrayList<Person>();
Iterator<Person> iterator = hs.iterator();
while (iterator.hasNext())
{
list.add(iterator.next());
}
return list;
}
//刪除張三、男、20
public List<Person> delete(List<Person> list){
Iterator<Person> iterator = list.iterator();
while (iterator.hasNext())
{
Person person = iterator.next();
if ("張三".equals(person.getName())&&"男".equals(person.getSex())&&20==person.getAge())
{
list.remove(person);
}
}
//System.out.println(list.size());
return list;
}
//打印所有人信息
public void printAllPerson(List<Person> list)
{
Iterator<Person> iterator = list.iterator();
while (iterator.hasNext())
{
System.out.println(iterator.next().toString());
}
}
}
//Ptest.java 主類
package com.ldxx.test;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
public class Ptest
{
public static void main(String[] args)
{
HashSet<Person> hs = new HashSet<Person>();
PersonUtils ps = new PersonUtils();
hs.add(new Person("張三", 20, "男"));
hs.add(new Person("李四", 21, "男"));
hs.add(new Person("王五", 12, "男"));
hs.add(new Person("趙四", 18, "女"));
System.out.println("1.所有男人的信息：");
ps.printMan(hs);
List<Person> list = ps.hashSetToList(hs);
//排序
Collections.sort(list, ps);
System.out.println("2.按年齡排序結果：");
ps.printAllPerson(list);
System.out.println("3.姓名是張三，年齡是20，性別是男的人後結果：");
ps.printAllPerson(ps.delete(list));
}
}