2.2.1 语法结构

public class 类名<泛型类型>{
}

举例：

public class Student<T> {
    private T flag;
    public T getFlag() {
        return flag;
    }
    public void setFlag(T flag) {
        this.flag = flag;
    }
}

public class Test {
    public static void main(String[] args) {
        Student<String> str = new Student<>();
        str.setFlag("爱摸鱼的TT~");
        System.out.println(str.getFlag());
        Student<Integer> str2 = new Student<>();
        str2.setFlag(1314);
        System.out.println(str2.getFlag());
    }
}