本文目录一览：

1. 一道java的题目？
2. 一道java编程题，请各位大神前来解答
3. 一道Java编程题，拜托了各位大神

一道java的题目？

1、可以利用hashMap实现。

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
public class Test {
    public static void main(String[] args) {
        System.out.println("输入多个字符串，以quit结束：");
        Scanner sc = new Scanner(System.in);
        Map<String, Integer> map = new HashMap<>();
        String word = "";
        while (!"quit".equals(word)) {
            // 避免大小写干扰，就全部转成小写
            word = sc.next().toLowerCase();
            if (!"quit".equals(word)) {
                if (!map.containsKey(word)) {
                    map.put(word, 1);
                } else {
                    // map中如果已经有当前key，就+1
                    map.put(word, map.get(word) + 1);
                }
            }
        }
        // 遍历hashmap
        for (String key : map.keySet()) {
            System.out.println(key + "  " + map.get(key));
        }
    }
}

一道java编程题，请各位大神前来解答

代码如下：

abstract class Animal {
    private String name;
    public Animal(String name) {
        this.name = name;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public abstract void enjoy();
}
class Cat extends Animal {
    private String eyesColor;
    public Cat(String name) {
        super(name);
    }
    public String getEyesColor() {
        return eyesColor;
    }
    public void setEyesColor(String eyesColor) {
        this.eyesColor = eyesColor;
    }
    @Override
    public void enjoy() {
        System.out.println("小猫" + getName() + "高兴的喵喵叫。");
    }
}
class Dog extends Animal {
    private String furColor;
    public Dog(String name) {
        super(name);
    }
    public String getFurColor() {
        return furColor;
    }
    public void setFurColor(String furColor) {
        this.furColor = furColor;
    }
    @Override
    public void enjoy() {
        System.out.println("狗狗" + getName() + "高兴的摇起了尾巴。");
    }
}
class Lady {
    private String name;
    private Animal pet;
    public Lady(String name, Animal pet) {
        this.name = name;
        this.pet = pet;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Animal getPet() {
        return pet;
    }
    public void setPet(Animal pet) {
        this.pet = pet;
    }
    public void myPetEnjoy() {
        pet.enjoy();
    }
}
public class App {
    public static void main(String[] args) {
        Cat cat = new Cat("Jerry");
        cat.setEyesColor("蓝色");
        Lady lady1 = new Lady("张女士", cat);
        lady1.myPetEnjoy();
        Dog dog = new Dog("旺财");
        dog.setFurColor("黄色");
        Lady lady2 = new Lady("王女士", dog);
        lady2.myPetEnjoy();
    }
}

一道Java编程题，拜托了各位大神

1. 定义一个Student类，包括学号，姓名，成绩三个字段，生成get,set和toString方法,实现Comparable接口，重写toCompare方法，方法里就是本题的逻辑，先按成绩比较，再按学好比较，使用TreeSet不实现这个接口会报错。

package Collection;
public class Student implements Comparable<Student> {
    private long sno;
    private String name;
    private int score;
    public long getSno() {
        return sno;
    }
    public void setSno(long sno) {
        this.sno = sno;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getScore() {
        return score;
    }
    public void setScore(int score) {
        this.score = score;
    }
    @Override
    public int compareTo(Student o) {
        if (this.score > o.score) {
            return 1;
        } else if (this.score < o.score) {
            return -1;
        } else {
            if (this.sno > o.sno) {
                return 1;
            } else {
                return -1;
            }
        }
    }
    @Override
    public String toString() {
        return "Student [sno=" + sno + ", name=" + name + ", score=" + score + "]";
    }
}

2. 然后写测试类，生成十个学生，然后插入treeset，直接遍历输出就是排序好的结果。

package Collection;
import java.util.Random;
import java.util.TreeSet;
public class TreeSetTest {
    public static void main(String[] args) {
        TreeSet<Student> ts = new TreeSet<>();
        for (int i = 0; i < 10; i++) {
            Student stu = new Student();
            stu.setName("student" + i);
            stu.setSno(170201 + i);
            stu.setScore(90 + new Random().nextInt(10));
            ts.add(stu);
        }
        for (Student stu : ts) {
            System.out.println(stu);
        }
    }
}

最后贴一个运行结果