用java代码实现创建一个student类，类内含有姓名、性别和年龄等成员变量，定义获取各变量的方法和思考方法; 创建一个teacher类，类内含有姓名、性别和年龄等成员变量，定义获取各变量的方法和教学方法；创建一个people类，声明两个成员变量分别是student类和teacher类的对象，定义获取student类和teacher类中成员变量及思考和教学的方法；创建一个主类，主类中创建一个student对象，一个teacher对象和一个people对象。输出对象的相关信息。

好的，您的问题已经被记录下来了。

下面是您所要求的Java代码实现：

class Student {
    String name;
    String gender;
    int age;

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

    public String getName() {
        return this.name;
    }

    public String getGender() {
        return this.gender;
    }

    public int getAge() {
        return this.age;
    }

    public void study() {
        System.out.println(this.name + " is studying.");
    }
}

class Teacher {
    String name;
    String gender;
    int age;

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

    public String getName() {
        return this.name;
    }

    public String getGender() {
        return this.gender;
    }

    public int getAge() {
        return this.age;
    }

    public void teach() {
        System.out.println(this.name + " is teaching.");
    }
}

class People {
    Student student;
    Teacher teacher;

    public People(Student student, Teacher teacher) {
        this.student = student;
        this.teacher = teacher;
    }

    public Student getStudent() {
        return this.student;
    }

    public Teacher getTeacher() {
        return this.teacher;
    }

    public void think() {
        System.out.println("I am thinking.");
    }
}

public class Main {
    public static void main(String[] args) {
        Student s = new Student("Tom", "male", 20);
        Teacher t = new Teacher("Jerry", "male", 30);
        People p = new People(s, t);

        System.out.println("Student: " + p.getStudent().getName() + ", " + p.getStudent().getGender() + ", " + p.getStudent().getAge());
        System.out.println("Teacher: " + p.getTeacher().getName() + ", " + p.getTeacher().getGender() + ", " + p.getTeacher().getAge());

        p.getStudent().study();
        p.getTeacher().teach();

        p.think();
    }
}

输出结果如下：

Student: Tom, male, 20
Teacher: Jerry, male, 30
Tom is studying.
Jerry is teaching.
I am thinking.