用Java设计一个Teacher类，最好有解释。

用Java设计一个Teacher类，最好有解释。

class Teacher{
private String Name;
private String TeacherID;
private String Address;
private String Course;
public String getName() {
return Name;
}
public void setName(String name) {
Name = name;
}
public String getTeacherID() {
return TeacherID;
}
public void setTeacherID(String teacherID) {
TeacherID = teacherID;
}
public String getAddress() {
return Address;
}
public void setAddress(String address) {
Address = address;
}
public String getCourse() {
return Course;
}
public void setCourse(String course) {
Course = course;
}

public String queryCourse(String qryString){
if(this.TeacherID.equals(qryString)){
System.out.println("Teacher:"+this.Name);
System.out.println("Course:"+this.Course);
return this.Course;
}else{
System.out.println("没有这个编号的老师");
return null;
}
}
}

public class Test {
public static void main(String[] args) {
Teacher t=new Teacher();
t.setAddress("Beijing");
t.setCourse("OS");
t.setName("Peter");
t.setTeacherID("001");
t.queryCourse("001");
t.queryCourse("002");
}
}