用Java编写在1.为Person类增加以下方法： （1）int getAge(int year) //返回在year年的年龄 （2）int getAge() //返回今年的年龄，重载 （3）int olderThen(Person per) //返回this与per //的年龄差值，按年龄比较对象大小 （4）boolean equals(Person per) //比较this与 // per引用实例对应成员变量值是否相等 2. 实现银行账户类构造方法成成员方法。 public class Account //账户类 { private String name; //储户姓名 private double balance; //账户余额 public Account(String name) //构造方法 public String getName() //返回账户名 public double balance() //查看账户余额 public boolean put(double value)//存款，存入金额 public double get(double value) //取款，参数为取款金额，返回实际取到金额 }的基础上，声明实现Comparble<T>接口，提供按照账户余额比较账户大小的方法；同时，使用Comparator<T>接口声明比较器类CompareName,按照账户名比较账户大小；编写main方法测试相应的接口实现方法。

下面是Java代码实现：

1. Person类：

public class Person implements Comparable<Person> {
    private String name;
    private int birthYear;
    
    public Person(String name, int birthYear) {
        this.name = name;
        this.birthYear = birthYear;
    }
    
    public int getAge(int year) {
        return year - birthYear;
    }
    
    public int getAge() {
        return getAge(Calendar.getInstance().get(Calendar.YEAR));
    }
    
    public int olderThan(Person per) {
        return this.birthYear - per.birthYear;
    }
    
    public boolean equals(Person per) {
        if (this == per) {
            return true;
        }
        
        if (per == null) {
            return false;
        }
        
        return this.name.equals(per.name) && this.birthYear == per.birthYear;
    }
    
    @Override
    public int compareTo(Person per) {
        return Integer.compare(this.birthYear, per.birthYear);
    }
}

2. Account类：

import java.util.Comparator;

public class Account implements Comparable<Account> {
    private String name;
    private double balance;
    
    public Account(String name) {
        this.name = name;
        this.balance = 0;
    }
    
    public String getName() {
        return name;
    }
    
    public double getBalance() {
        return balance;
    }
    
    public boolean put(double value) {
        if (value <= 0) {
            return false;
        }
        
        balance += value;
        return true;
    }
    
    public double get(double value) {
        if (value <= 0 || balance < value) {
            return 0;
        }
        
        balance -= value;
        return value;
    }
    
    @Override
    public int compareTo(Account acc) {
        return Double.compare(this.balance, acc.balance);
    }
    
    public static class CompareName implements Comparator<Account> {
        @Override
        public int compare(Account acc1, Account acc2) {
            return acc1.name.compareTo(acc2.name);
        }
    }
}

3. 测试代码：

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        // 测试Person类
        Person p1 = new Person("Tom", 1990);
        Person p2 = new Person("Jerry", 1995);
        System.out.println("Tom's age in 2021: " + p1.getAge(2021));
        System.out.println("Jerry's age in 2021: " + p2.getAge(2021));
        System.out.println("Tom's age: " + p1.getAge());
        System.out.println("Jerry's age: " + p2.getAge());
        System.out.println("Tom older than Jerry: " + p1.olderThan(p2));
        System.out.println("Tom equals Jerry: " + p1.equals(p2));
        
        // 测试Account类
        List<Account> accounts = new ArrayList<>();
        Account acc1 = new Account("Tom");
        acc1.put(1000);
        accounts.add(acc1);
        Account acc2 = new Account("Jerry");
        acc2.put(2000);
        accounts.add(acc2);
        Account acc3 = new Account("Alice");
        acc3.put(1500);
        accounts.add(acc3);
        
        // 按照余额排序
        System.out.println("Sort by balance:");
        Collections.sort(accounts);
        for (Account acc : accounts) {
            System.out.println(acc.getName() + " " + acc.getBalance());
        }
        
        // 按照账户名排序
        System.out.println("Sort by name:");
        Collections.sort(accounts, new Account.CompareName());
        for (Account acc : accounts) {
            System.out.println(acc.getName() + " " + acc.getBalance());
        }
    }
}