Java——集合、IO流练习

用代码实现以下需求
(1)定义学生类,包含姓名(String name),性别(String gender),年龄(int age)三个属性,生成空参有参构造,set和get方法,toString方法
(2)键盘录入6个学员信息(录入格式:张三,男,25),要求有两个相同的信息,将6个学员信息存入到ArrayList集合中
(3)将存有6个学员信息的ArrayList集合对象写入到D:\StudentInfo.txt文件中
(4)读取D:\StudentInfo.txt文件中的ArrayList对象
(5)对ArrayList集合中的6个学生对象进行去重并按照年龄从小到大的顺序排序
(6)将ArrayList集合中排序后的结果利用PrintWriter流写入到E:\StudentInfo.txt文件中(写入格式：张三-男-25)

实现代码：

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Set;

public class HomeWork1 {
	public static void main(String[] args) throws IOException {
		ArrayList<Student> arrayList = Init();
		writeStu(arrayList);
		readStu();
		ArrayList<Student> newArray = sortStu(arrayList);
		print(newArray);
	}
/*(2)键盘录入6个学员信息(录入格式:张三,男,25),
		要求有两个相同的信息,将6个学员信息存入到ArrayList集合中
*/
	public static ArrayList<Student> Init() {
		Student s1 = new Student("张三","男",25);
		Student s2 = new Student("小明","男",20);
		Student s3 = new Student("张三","男",25);
		Student s4 = new Student("李四","男",18);
		Student s5 = new Student("王五","女",25);
		Student s6 = new Student("赵六","男",30);
		ArrayList<Student> list = new ArrayList<>();
		list.add(s1);
		list.add(s2);
		list.add(s3);
		list.add(s4);
		list.add(s5);
		list.add(s6);
		
		return list;
	}
	
//	(3)将存有6个学员信息的ArrayList集合对象写入到D:\\StudentInfo.txt文件中
	public static void writeStu(ArrayList<Student> arrayList) throws IOException {
		BufferedWriter bfw = new BufferedWriter( new FileWriter("D:\\360MoveData\\Users\\xucc\\Desktop\\StudentInfo.txt"));
		for(Student s : arrayList) {
			bfw.write(s.toString());
			bfw.newLine();
			bfw.flush();
		}
		bfw.close();
	}
	
//	(4)读取D:\\StudentInfo.txt文件中的ArrayList对象
	public static void readStu() throws IOException {
		BufferedReader bfr = new  BufferedReader(new FileReader("D:\\360MoveData\\Users\\xucc\\Desktop\\StudentInfo.txt"));
		String line = "";
		while ((line = bfr.readLine()) != null) {
			System.out.println(line);
			
		}
		bfr.close();
	}
	
//	(5)对ArrayList集合中的6个学生对象进行去重并按照年龄从小到大的顺序排序
	public static ArrayList<Student> sortStu(ArrayList<Student> arrayList) {
		ArrayList<Student> newArr = new ArrayList<>();
		Set<Student> set = new HashSet<Student>();
		for(Student s1 : arrayList )
			set.add(s1);
		
		for(Student s2 : set)
			newArr.add(s2);
		
		for(int i=1 ; i<newArr.size() ; i++) //控制趟数
			for(int j=0 ; j<newArr.size()-1-i ; j++) {	//内循环为第i趟，相邻两个数比较次数
				if(newArr.get(j).age > newArr.get(j+1).age) {
					Student s = newArr.get(j);
					newArr.set(j, newArr.get(j+1));
					newArr.set(j+1, s);
				}
			}
		return newArr;
	}
	
//	(6)将ArrayList集合中排序后的结果利用PrintWriter流写入到E:\\StudentInfo.txt文件中(写入格式：张三-男-25)
	public static void print(ArrayList<Student> arrayList) throws IOException {
		PrintWriter pw = new PrintWriter("D:\\360MoveData\\Users\\xucc\\Desktop\\StudentInfo1.txt");
		for(Student s : arrayList) {
			pw.println(s.name+"-"+s.gender+"-"+s.age);
			pw.flush();
		}
		pw.close();
	}
}

//新建内部类：(1)定义学生类,包含姓名(String name),性别(String gender),年龄(int age)三个属性,生成空参有参构造,set和get方法,toString方法
class Student{
	String name;
	String gender;
	int age;
	public Student(String name, String gender, int age) {
		super();
		this.name = name;
		this.gender = gender;
		this.age = age;
	}
	public Student() {
		super();
		
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getGender() {
		return gender;
	}
	public void setGender(String gender) {
		this.gender = gender;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	@Override
	public String toString() {
		return "Student [name=" + name + ", gender=" + gender + ", age=" + age + "]";
	}
	
//	@Overrid重写hashCode和equals方法，使储存Student对象的set集合不重复
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((gender == null) ? 0 : gender.hashCode());
		result = prime * result + age;
		result = prime * result + ((name == null) ? 0 : name.hashCode());
		return result;
	}
	
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Student other = (Student) obj;
		if (age != other.age)
			return false;
		if(gender != other.gender)
			return false;
		if (name == null) {
			if (other.name != null)
				return false;
		} else if (!name.equals(other.name))
			return false;
		
		return true;
	}
	
}