1 代码演练
1.1 代码演练1(组合模式1)
1.2 代码演练2(组合模式1之完善)
1 代码演练
1.1 代码演练1(组合模式1)
需求:
打印出木木网的课程结构,
我们用一个组建类作为接口,课程类和目录类继承。
uml:
组件类:
package com.geely.design.pattern.structural.composite; import java.io.IOException; /** * 课程目录组件,可以被课程和课程目录继承 */ public abstract class CatalogComponent { //添加目录 public void addCatalog(CatalogComponent catalogComponent){ throw new UnsupportedOperationException("不支持添加操作"); } //移除目录 public void removeCatalog(CatalogComponent catalogComponent){ throw new UnsupportedOperationException("不支持移除操作"); } //得到课程名称 public String getName(CatalogComponent catalogComponent){ throw new UnsupportedOperationException("不支持获取名称操作"); } //得到课程价格 public double getPrice(CatalogComponent catalogComponent){ throw new UnsupportedOperationException("不支持获取价格操作"); } //打印目录 注意这里抛出异常 是为了抽象类 的方法不被调取,之所以没有写抽象方法,是因为目录类和课程类总有些方法没有实现 public void printCatalog(){ throw new UnsupportedOperationException("不支持的操作"); } }
课程类:
package com.geely.design.pattern.structural.composite; public class Course extends CatalogComponent { private String sCourseName; private double sCoursePrice; public Course(String sCourseName, double sCoursePrice) { this.sCourseName = sCourseName; this.sCoursePrice = sCoursePrice; } @Override public String getName(CatalogComponent catalogComponent) { return this.sCourseName; } @Override public double getPrice(CatalogComponent catalogComponent) { return this.sCoursePrice; } @Override public void printCatalog() { System.out.println("课程名称为"+sCourseName+", 课程价格为"+sCoursePrice); } }
目录类:
package com.geely.design.pattern.structural.composite; import java.util.ArrayList; import java.util.List; public class CourseCatalog extends CatalogComponent { private List<CatalogComponent> items = new ArrayList<CatalogComponent>(); private String name; /** * 一定要写有参构造方法,因为后边还要打印日志 * @param name */ public CourseCatalog(String name) { this.name = name; } @Override public void addCatalog(CatalogComponent catalogComponent) { items.add(catalogComponent); } @Override public void removeCatalog(CatalogComponent catalogComponent) { items.remove(catalogComponent); } /** * 对于目录来说,课程名字可以出重写, * 所以这里可以进行修改!!! * @param catalogComponent * @return */ @Override public String getName(CatalogComponent catalogComponent) { return this.name; } @Override public void printCatalog() { for(CatalogComponent catalogComponent :items){ catalogComponent.printCatalog(); } } }
测试类:
package com.geely.design.pattern.structural.composite; public class Test { public static void main(String [] args){ CatalogComponent totalCourse = new CourseCatalog("课程总目录"); CatalogComponent linuxCourse = new Course("linux课程",11); CatalogComponent windowsCourse = new Course("windows操作系统课程",22); CatalogComponent javaCatalog = new CourseCatalog("java课程目录"); CatalogComponent javaHibernate = new Course("hibernate课程",33); CatalogComponent javaStruct2 = new Course("Struct2课程",44); CatalogComponent javaSpring = new Course("Spring课程",55);
javaCatalog.addCatalog(javaHibernate); javaCatalog.addCatalog(javaStruct2);
javaCatalog.addCatalog(javaSpring); totalCourse.addCatalog(linuxCourse); totalCourse.addCatalog(windowsCourse);
totalCourse.addCatalog(javaCatalog); totalCourse.printCatalog(); } }
打印日志:
课程名称为linux课程, 课程价格为11.0 课程名称为windows操作系统课程, 课程价格为22.0 课程名称为hibernate课程, 课程价格为33.0 课程名称为Struct2课程, 课程价格为44.0 课程名称为Spring课程, 课程价格为55.0 Process finished with exit code 0
1.2 代码演练2(组合模式1之完善)
1.1的缺陷是
没有打出目录结构
只修改了课程目录类 和测试类:
package com.geely.design.pattern.structural.composite; import java.util.ArrayList; import java.util.List; public class CourseCatalog extends CatalogComponent { private List<CatalogComponent> items = new ArrayList<CatalogComponent>(); private String name; private Integer level;//加入等级, 判断是否是目录,之所以不用int 是因为不用给它初始值, 也好做空判断 /** * 一定要写有参构造方法,因为后边还要打印日志 * @param name */ public CourseCatalog(String name,Integer level) { this.name = name; this.level = level; } @Override public void addCatalog(CatalogComponent catalogComponent) { items.add(catalogComponent); } @Override public void removeCatalog(CatalogComponent catalogComponent) { items.remove(catalogComponent); } /** * 对于目录来说,课程名字可以出重写, * 所以这里可以进行修改!!! * @param catalogComponent * @return */ @Override public String getName(CatalogComponent catalogComponent) { return this.name; } @Override public void printCatalog() { System.out.println(this.name);//打印目录名字 for(CatalogComponent catalogComponent :items){ if(this.level != null){ for(int i = 0;i < level;i++){ System.out.print(" "); } } catalogComponent.printCatalog();//调用课程或者目录打印方法 } } }
测试类:
package com.geely.design.pattern.structural.composite;
public class Test {
public static void main(String [] args){
CatalogComponent totalCourse = new CourseCatalog("课程总目录",1);
CatalogComponent linuxCourse = new Course("linux课程",11);
CatalogComponent windowsCourse = new Course("windows操作系统课程",22);
CatalogComponent javaCatalog = new CourseCatalog("java课程目录",2);
CatalogComponent javaHibernate = new Course("hibernate课程",33);
CatalogComponent javaStruct2 = new Course("Struct2课程",44);
CatalogComponent javaSpring = new Course("Spring课程",55);
javaCatalog.addCatalog(javaHibernate);
javaCatalog.addCatalog(javaStruct2);
javaCatalog.addCatalog(javaSpring);
totalCourse.addCatalog(linuxCourse);
totalCourse.addCatalog(windowsCourse);
totalCourse.addCatalog(javaCatalog);
totalCourse.printCatalog();
}
}
打印日志:
课程总目录 课程名称为linux课程, 课程价格为11.0 课程名称为windows操作系统课程, 课程价格为22.0 java课程目录 课程名称为hibernate课程, 课程价格为33.0 课程名称为Struct2课程, 课程价格为44.0 课程名称为Spring课程, 课程价格为55.0 Process finished with exit code 0
课程类:
package com.geely.design.pattern.structural.composite; public class Course extends CatalogComponent { private String sCourseName; private double sCoursePrice; public Course(String sCourseName, double sCoursePrice) { this.sCourseName = sCourseName; this.sCoursePrice = sCoursePrice; } @Override public String getName(CatalogComponent catalogComponent) { return this.sCourseName; } @Override public double getPrice(CatalogComponent catalogComponent) { return this.sCoursePrice; } @Override public void printCatalog() { System.out.println("课程名称为"+sCourseName+", 课程价格为"+sCoursePrice); } }
组件类:
package com.geely.design.pattern.structural.composite; import java.io.IOException; /** * 课程目录组件,可以被课程和课程目录继承 */ public abstract class CatalogComponent { //添加目录 public void addCatalog(CatalogComponent catalogComponent){ throw new UnsupportedOperationException("不支持添加操作"); } //移除目录 public void removeCatalog(CatalogComponent catalogComponent){ throw new UnsupportedOperationException("不支持移除操作"); } //得到课程名称 public String getName(CatalogComponent catalogComponent){ throw new UnsupportedOperationException("不支持获取名称操作"); } //得到课程价格 public double getPrice(CatalogComponent catalogComponent){ throw new UnsupportedOperationException("不支持获取价格操作"); } //打印目录 注意这里抛出异常 是为了抽象类 的方法不被调取,之所以没有写抽象方法,是因为目录类和课程类总有些方法没有实现 public void printCatalog(){ throw new UnsupportedOperationException("不支持的操作"); } }
诸葛