泛型的实际应用，该怎么敲？

Question

这用泛型该怎么做？不太懂泛型的实际应用，要是用了泛型，该怎么定义数组存储？成员变量又该怎么处理？望代码

Answer 1

这个你定义2个类，Person1类，拥有姓名性别年龄三个字段
Person2类，拥有姓名电话字段
然后排序算法 T 代表任意类型

找了一个类似的例子，你看下

public class Person1 {
    private String name;
    private String gender;
    private int age;

    public Person1(String name, String gender, int age) {
        this.name = name;
        this.gender = gender;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public String getGender() {
        return gender;
    }

    public int getAge() {
        return age;
    }
}

public class Person2 {
    private String name;
    private String phone;

    public Person2(String name, String phone) {
        this.name = name;
        this.phone = phone;
    }

    public String getName() {
        return name;
    }

    public String getPhone() {
        return phone;
    }
}

public class Sorter {
    public interface Selector<T> {
        int compare(T obj1, T obj2);
    }

    public static <T> void sort(T[] data, Selector<T> selector) {
        int len = data.length;
        for (int i = 0; i < len - 1; i++) {
            boolean flag = true;
            for (int j = 0; j < len - 1 - i; j++) {
                if (selector.compare(data[j], data[j + 1]) > 0) {
                    T temp = data[j];
                    data[j] = data[j + 1];
                    data[j + 1] = temp;
                    flag = false;
                }
            }
            if (flag) {
                break;
            }
        }
    }
}

调用

Person1[] persons1 = {
        new Person1("Amy", "Female", 25),
        new Person1("Bob", "Male", 30),
        new Person1("Charlie", "Male", 20),
        new Person1("David", "Male", 35),
        new Person1("Emily", "Female", 28)
};
Sorter.sort(persons1, new Sorter.Selector<Person1>() {
    public int compare(Person1 obj1, Person1 obj2) {
        if (obj1.getAge() > obj2.getAge()) {
            return 1;
        } else if (obj1.getAge() < obj2.getAge()) {
            return -1;
        } else {
            return 0;
        }
    }
});
for (Person1 p : persons1) {
    System.out.println(p.getName() + " " + p.getGender() + " " + p.getAge());
}
System.out.println();

Person2[] persons2 = {
        new Person2("Amy", "123456"),
        new Person2("Bob", "234567"),
        new Person2("Charlie", "345678"),
        new Person2("David", "456789"),
        new Person2("Emily", "567890")
};
Sorter.sort(persons2, new Sorter.Selector<Person2>() {
    public int compare(Person2 obj1, Person2 obj2) {
        return obj1.getName().compareTo(obj2.getName());
    }
});
for (Person2 p : persons2) {
    System.out.println(p.getName() + " " + p.getPhone());
}