JavaEE-实验二 Java集合框架实验

该博客仅专为我的小伙伴提供参考而附加，没空加上代码具体解析，望各位谅解

1、  使用类String类的分割split 将字符串  “Solutions to selected exercises can be found in the electronic document The Thinking in Java Annotated Solution Guide, available for a small fee from BruceEckel” 单词提取输出。单词以空格或,分割。

package experiment;
public class Split {
    public static void main(String[] args) {
        String str="Solutions to selected exercises can be found in the electronic document The Thinking in Java 
　　　　　　　　　　　　Annotated Solution Guide, available for a small fee from BruceEckel";
        String[] s = str.split(" ");
        for(String ss:s) {
            System.out.print(ss+",");
        }
    }
}

示例截图

 

2、 设计一个程序计算2011-05-01日与系统当前日期相差的天数。

 package experiment;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class days {
    public static void main(String[] args) throws ParseException  {
        Date date1=new Date();
        SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd");
        String s=new String("2011-05-01");
        Date date2 = format.parse(s);
        int days=(int)((date1.getTime()-date2.getTime())/(1000*60*60*24));
        System.out.println("今天日期："+format.format(date1)+"距离"+s+" "+days+"天");
    }
}

示例截图

3、将本学期开设的课程名称加入到HashSet中，并使用迭代器遍历输出。

package experiment;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

public class Courses {
    public static void main(String[] args) {
        Set<String> set=new HashSet<String>();
        set.add("Python");
        set.add("JavaEE");
        set.add("软件工程");
        set.add("操作系统");
        set.add("计算机组成");
        Iterator<String> it=set.iterator();
        while(it.hasNext()) {
            System.out.println(it.next());
        }
    }
}

示例截图

4 理解元素是如何排序的。完成以下实验：

 1）定义一个学生类：属性有学号、姓名、专业、高数成绩、外语成绩、Java课程成绩。

package experiment;

public class Student {
    private String sno;
    private String sname;
    private String department;
    private int maths;
    private int english;
    private int java;
    private int score;
    
    
    public int getScore() {
        return score;
    }
    public Student(String sno, String sname, String department, int maths, int english, int java) {
        this.sno = sno;
        this.sname = sname;
        this.department = department;
        this.maths = maths;
        this.english = english;
        this.java = java;
        this.score=english+java+maths;
    }
    public String getSno() {
        return sno;
    }
    public void setSno(String sno) {
        this.sno = sno;
    }
    public String getSname() {
        return sname;
    }
    public void setSname(String sname) {
        this.sname = sname;
    }
    public String getDepartment() {
        return department;
    }
    public void setDepartment(String department) {
        this.department = department;
    }
    public int getMaths() {
        return maths;
    }
    public void setMaths(int maths) {
        this.maths = maths;
    }
    public int getEnglish() {
        return english;
    }
    public void setEnglish(int english) {
        this.english = english;
    }
    public int getJava() {
        return java;
    }
    public void setJava(int java) {
        this.java = java;
    }
    @Override
    public String toString() {
        return "Student [sno=" + sno + ", sname=" + sname + ", department=" + department + ", maths=" + maths
                + ", english=" + english + ", java=" + java + ", 总分=" + score + "]";
    }
    
}

比较类

package experiment;

import java.util.Comparator;

public class MyCmp implements Comparator<Student>{
    @Override
    public int compare(Student o1, Student o2) {
        return o2.getScore()-o1.getScore();
    }
 }

   2)在测试类中生成多个学生类的对象，放入TreeSet中，要求按照三门课总成绩从高到低排序，总成绩相等按学号排序。输出排序结果。

package experiment;

import java.util.Iterator;
import java.util.TreeSet;

public class test {
    public static void main(String[] args) {
        Student s1=new Student("1", "c1", "计算机", 98, 80, 92);
        Student s2=new Student("2", "c2", "软工", 80, 84, 99);
        Student s3=new Student("3", "c3", "国交", 88, 79, 82);
        Student s4=new Student("4", "c4", "计算机", 78, 90, 82);
        TreeSet<Student> ts=new TreeSet<Student>(new MyCmp());
        ts.add(s1);
        ts.add(s2);
        ts.add(s3);
        ts.add(s4);
        Iterator<Student> it=ts.iterator();
        while(it.hasNext()){
            Student s=(Student)it.next();
            System.out.println(s.toString());
            }

    }
}

示例截图