设计模式
1、工厂设计模式
用来生产类对象，避免用户直接接触派生类
给出一个例子：
接口：Teacher
interface Teacher{
public void teach();
}
class EnglishTeacher implements Teacher{
public void teach(){
System.out.println("上英语课");
}
}
class MathTeacher implements Teacher{
public void teach(){
System.out.println("上数学课");
}
}
class TeacherFactory{
public static Teacher getTeacher(int flag){
Teacher teacher = null;
if(0 == flag){
teacher = new EnglishTeacher();
}
else if(1 == flag ){
teacher = new MathTeacher();
}
return teacher;
}
}
class Test{
public static void main(String args []){
int flag = 1;
Teacher teacher = TeacherFactory.getTeacher(flag);
teacher.teach();
}
}
2、装饰者设计模式
主要用于降低继承的复杂度
在上面的基础上修改代码
class GradeOne implements Teacher{
Teacher gradeOneTeacher = null;
GradeOne(Teacher teacher){
gradeOneTeacher = teacher;
}
public void teach(){
System.out.println("我是一年级的老师");
gradeOneTeacher.teach();
}
}
class GradeTwo implements Teacher{
Teacher gradeTwoTeacher = null;
GradeTwo(Teacher teacher){
gradeTwoTeacher = teacher;
}
public void teach(){
System.out.println("我是二年级的老师");
gradeTwoTeacher.teach();
}
}
class Test{
public static void main(String args []){
//下面的方法是申请一个一年级的数学老师
//装饰者模式
int flag = 1;
Teacher teacher = TeacherFactory.getTeacher(flag);
GradeOne gradeOneTeacher = new GradeOne(teacher);
gradeOneTeacher.teach();
}
}