3.29作业

3.29作业

1.

public class Student implements Serializable {/*** 定义学生类Student ，属性：姓名，学号，年龄，成绩* 提供：无参和全参构造器，生成get和set方法，重写toString ，equals ,hashCode*使用全参构造器创建3个学生对象，放入集合中*使用对象流将这个学生集合写入到本地*使用对象流从本地文件把学生信息读出来，并打印*/private String name;private int id;private int age;private double fraction;public Student() {}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getId() {return id;}public void setId(int id) {this.id = id;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public double getFraction() {return fraction;}public void setFraction(double fraction) {this.fraction = fraction;}public Student(String name, int id, int age, double fraction) {this.name = name;this.id = id;this.age = age;this.fraction = fraction;}@Overridepublic boolean equals(Object o) {if (this == o) return true;if (o == null || getClass() != o.getClass()) return false;Student student = (Student) o;return id == student.id && age == student.age && Doublepare(student.fraction, fraction) == 0 && Objects.equals(name, student.name);}@Overridepublic int hashCode() {return Objects.hash(name, id, age, fraction);}@Overridepublic String toString() {return "Student{" +"name='" + name + ''' +", id=" + id +", age=" + age +", fraction=" + fraction +'}';}
}

public static void main(String[] args) throws Exception {Student s1 = new Student("嘎子" , 110 , 18 , 90.0);Student s2 = new Student("潘子" , 111 , 19 , 95.5);Student s3 = new Student("华子" , 112 , 20 , 908.5);List<Student> list = new ArrayList<>();list.add(s1);list.add(s2);list.add(s3);FileOutputStream fo = new FileOutputStream("s.student");ObjectOutputStream oo = new ObjectOutputStream(fo);oo.writeObject(list);oo.close();}

public static void main(String[] args) throws Exception {FileInputStream fi = new FileInputStream("s.student");ObjectInputStream oi = new ObjectInputStream(fi);Object o = oi.readObject();if (o instanceof List){List list = (List) o;System.out.println(list);}oi.close();
}

2.

public class myThread extends Thread{public myThread() {}public myThread(String name) {super(name);}@Overridepublic void run() {for (int i = 0; i < 1000; i++) {System.out.Name() + i);}}
}

public static void main(String[] args) {myThread t1 = new myThread();myThread t2 = new myThread("二号线程");t1.start();t2.start();System.out.println("结束");
}

public class myThread2 implements Runnable{@Overridepublic void run() {for (int i = 0; i < 1000; i++) {System.out.println(i);}}
}

public static void main(String[] args) {myThread2 mt1 = new myThread2();myThread2 mt2 = new myThread2();Thread t1 = new Thread(mt1 , "一号");Thread t2 = new Thread(mt2 , "二号");t1.start();t2.start();
}

public class myThread3Test {public static void main(String[] args) {//匿名内部类new Thread(new Runnable() {@Overridepublic void run() {for (int i = 0; i < 1000; i++) {System.out.println(Thread.currentThread().getName() + i);}}}).start();}
}