Java设计模式学习以及底层源码分析
源码在分支master
工厂模式
把具体创建产品的细节封装起来，你要什么产品，我给你什么产品即可。简单工厂模式
工厂方法模式
缓存层：抽象类
抽象工厂模式
缓存层是：接口
原型模式
问题：
原型模式的源码分析：Spring 中的 getBean()这个方法低层实现。是否选择单例、和原型模式。
自己的Code
/* * Package: com.example.demo.design.prototype * Type: User * Date: 2022-03-06 14:22 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.prototype;import lombok.Data;import lombok.extern.slf4j.Slf4j;/ * 功能描述： 原型模式分析： * 无线创建相同对象 但是对象的地址值都不是相同的 * * * @author Songxianyang * @date 2022-03-06 14:22 */@Data@Slf4jpublic class User implements Cloneable { private String name; private int age; public User(String name, int age) { this.name = name; this.age = age; } @Override public String toString() { return "User{" + "name='" + name + '\'' + ", age=" + age + '}'; } @Override protected Object clone() { User user =null; try { user = (User) super.clone(); } catch (CloneNotSupportedException e) { log.error("clone: ", "无法或不应克隆对象"); } return user; }}实现：
/* * Package: com.example.demo.design.prototype * Type: Test * Date: 2022-03-06 14:29 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.prototype;/ * 功能描述： * * @author Songxianyang * @date 2022-03-06 14:29 */public class Test { public static void main(String[] args) { User user = new User("sxy", 22); System.out.println(user); System.out.println(user.clone()); System.out.println(user.clone()); System.out.println(user==user.clone()); }}
建造者模式
源码盘点
项目截图
/* * Package: com.example.demo.design.builder * Type: BuilderHouse * Date: 2022-03-06 21:14 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.builder;/ * 功能描述： 抽象的一个构建者 * * @author Songxianyang * @date 2022-03-06 21:14 */public interface BuilderHouse { House house = new House(); / * 地基 */ void foundation(); / * 砌墙 */ void buildWall(); / * 封顶 */ void capping(); / * 构建对象 * @return house */ default House builder() { return house; }}/* * Package: com.example.demo.design.builder * Type: Commander * Date: 2022-03-06 21:29 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.builder;/ * 功能描述： 指挥者:负责怎么去执行 ：行为 * * @author Songxianyang * @date 2022-03-06 21:29 */public class Commander { BuilderHouse builderHouse = null; public Commander(BuilderHouse builderHouse) { this.builderHouse = builderHouse; } public House builder () { builderHouse.foundation(); builderHouse.buildWall(); builderHouse.capping(); return builderHouse.builder(); }}/* * Package: com.example.demo.design.builder * Type: HighHouse * Date: 2022-03-06 21:28 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.builder;/ * 功能描述： 高楼 * * @author Songxianyang * @date 2022-03-06 21:28 */public class HighHouse implements BuilderHouse { @Override public void foundation() { System.out.println("高楼打地基"); } @Override public void buildWall() { System.out.println("高楼砌墙"); } @Override public void capping() { System.out.println("高楼 吊顶"); }}/* * Package: com.example.demo.design.builder * Type: House * Date: 2022-03-06 21:11 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.builder;import lombok.Data;/ * 功能描述： 房子是一个产品类 * * @author Songxianyang * @date 2022-03-06 21:11 */@Datapublic class House { private String spar; private Integer height;}/* * Package: com.example.demo.design.builder * Type: PlainHouse * Date: 2022-03-06 21:20 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.builder;/ * 功能描述：普通房子 实现类 * * @author Songxianyang * @date 2022-03-06 21:20 */public class PlainHouse implements BuilderHouse { @Override public void foundation() { System.out.println("普通房子打地基"); } @Override public void buildWall() { System.out.println("普通房子砌墙"); } @Override public void capping() { System.out.println("普通房子 吊顶"); }}/* * Package: com.example.demo.design.builder * Type: Test * Date: 2022-03-06 21:33 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.builder;/ * 功能描述：测试类 * * @author Songxianyang * @date 2022-03-06 21:33 */public class Test { public static void main(String[] args) { //普通房子 PlainHouse plainHouse = new PlainHouse(); Commander commander = new Commander(plainHouse); commander.builder(); System.out.println("-------------------"); //高楼大厦 HighHouse highHouse = new HighHouse(); Commander high = new Commander(highHouse); high.builder(); }}测试截图
源码分析
new StringBuilder();建造者 建造一个产品需要那些步骤：Appendable具体建造出什么样的抽象对象具有什么功能：AbstractStringBuilder 指挥者：具体指挥返回什么样的对象StringBuilder、StringBuffer适配器模式-结构化
类适配器
上代码
/* * Package: com.example.demo.design.adapter.classadapter * Type: Voltage * Date: 2022-03-12 10:14 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.classadapter;/ * 功能描述：5V电压转换器 * * @author Songxianyang * @date 2022-03-12 10:14 */public class Change extends Source implements VoltageAdapter { @Override public String output5v() { String v220 = super.output(); v220="5v"; return v220; }}/* * Package: com.example.demo.design.adapter.classadapter * Type: Phone * Date: 2022-03-12 10:28 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.classadapter;/ * 功能描述：手机充电 * * @author Songxianyang * @date 2022-03-12 10:28 */public class Phone { private VoltageAdapter adapter; public Phone(VoltageAdapter adapter) { this.adapter = adapter; } public void chargePhone() { System.out.println("我得手机以及充上"+adapter.output5v()); }}/* * Package: com.example.demo.design.adapter * Type: Source * Date: 2022-03-12 10:03 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.classadapter;/ * 类适配器 * 功能描述：电源类220v 被适配器 * * @author Songxianyang * @date 2022-03-12 10:03 */public class Source { public String output() { return "220v"; }}/* * Package: com.example.demo.design.adapter.classadapter * Type: Test * Date: 2022-03-12 10:34 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.classadapter;/ * 功能描述： * * @author Songxianyang * @date 2022-03-12 10:34 */public class Test { public static void main(String[] args) { Phone phone = new Phone(new Change()); phone.chargePhone(); }}/* * Package: com.example.demo.design.adapter.classadapter * Type: SourceAdapter * Date: 2022-03-12 10:06 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.classadapter;/ * 功能描述： 充电器适配器 * * @author Songxianyang * @date 2022-03-12 10:06 */public interface VoltageAdapter { / * 输出5v电压 * @return s */ String output5v();}
对象适配器
/* * Package: com.example.demo.design.adapter.classadapter * Type: Voltage * Date: 2022-03-12 10:14 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.objadapter;/ * 功能描述：5V电压转换器 ：适配器 * * @author Songxianyang * @date 2022-03-12 10:14 */public class Change { private Source source = new Source(); public String output5v() { String v220 = source.output(); v220="5v"; return v220; }}/* * Package: com.example.demo.design.adapter.classadapter * Type: Phone * Date: 2022-03-12 10:28 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.objadapter;/ * 功能描述：手机充电 * * @author Songxianyang * @date 2022-03-12 10:28 */public class Phone { private Change change= new Change(); public void chargePhone() { System.out.println("我得手机以及充上"+change.output5v()); }}/* * Package: com.example.demo.design.adapter * Type: Source * Date: 2022-03-12 10:03 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.objadapter;/ * 类适配器 * 功能描述：电源类220v 被适配器 * * @author Songxianyang * @date 2022-03-12 10:03 */public class Source { public String output() { return "220v"; }}/* * Package: com.example.demo.design.adapter.classadapter * Type: Test * Date: 2022-03-12 10:34 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.objadapter;/ * 功能描述： * * @author Songxianyang * @date 2022-03-12 10:34 */public class Test { public static void main(String[] args) { Phone phone = new Phone(); phone.chargePhone(); }}
接口适配器
结构：
代码以及优化
/* * Package: com.example.demo.design.adapter.interfaceadapter * Type: AVoltageAdapter * Date: 2022-03-12 15:48 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.interfaceadapter;/ * 功能描述：抽象的一个多种电压 初始化 * * @author Songxianyang * @date 2022-03-12 15:48 */public abstract class AbsVoltageAdapter implements IVoltageAdapter { @Override public String v5() { return null; } @Override public String v21() { return null; }}/* * Package: com.example.demo.design.adapter.interfaceadapter * Type: V * Date: 2022-03-12 15:47 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.interfaceadapter;/ * 功能描述： 多种电压 接口 * * @author Songxianyang * @date 2022-03-12 15:47 */public interface IVoltageAdapter { / * 充手机 * @return s */ public String v5(); / * 充电车 * @return s */ String v21(); /* ...... */}/* * Package: com.example.demo.design.adapter.interfaceadapter * Type: Phone * Date: 2022-03-12 15:56 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.interfaceadapter;/ * 功能描述：手机需要5v电压 * * @author Songxianyang * @date 2022-03-12 15:56 */public class Phone { private AbsVoltageAdapter abs; public Phone(AbsVoltageAdapter abs) { this.abs = abs; } public void change() { System.out.println("小米手机已经充上"+abs.v5()); }}/* * Package: com.example.demo.design.adapter.interfaceadapter * Type: PhoneAdapter * Date: 2022-03-12 15:53 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.interfaceadapter;/ * 功能描述：手机适配器5v * 优化点 * @author Songxianyang * @date 2022-03-12 15:53 */public class PhoneAdapter extends AbsVoltageAdapter { @Override public String v5() { return "5v"; }}/* * Package: com.example.demo.design.adapter.classadapter * Type: Test * Date: 2022-03-12 10:34 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.adapter.interfaceadapter;/ * 功能描述： * * @author Songxianyang * @date 2022-03-12 10:34 */public class Test { public static void main(String[] args) { Phone phone = new Phone(new PhoneAdapter()); phone.change(); }}
源码分析 mvc
源码 分析
DispatcherServlet dispatcherServlet = new DispatcherServlet();DispatcherServlet：{方法：doDispatch(HttpServletRequest request){// 获取 requestHttpServletRequest processedRequest = request;// 执行器对象：Handler HandlerExecutionChain mappedHandler = null; // 获取映射执行器对象 mappedHandler = this.getHandler(processedRequest); // 获取具体的 HandlerAdapter 的适配器 HandlerAdapter ha = this.getHandlerAdapter(mappedHandler.getHandler()); // 不同的适配器 返回不同的 mv mv = ha.handle(processedRequest, response, mappedHandler.getHandler());//被调用的代码//遍历获取具体的handler 并返回protected HandlerAdapter getHandlerAdapter(Object handler) throws ServletException { if (this.handlerAdapters != null) { Iterator var2 = this.handlerAdapters.iterator(); while(var2.hasNext()) { HandlerAdapter adapter = (HandlerAdapter)var2.next(); if (adapter.supports(handler)) { return adapter; } } } throw new ServletException("No adapter for handler [" + handler + "]: The DispatcherServlet configuration needs to include a HandlerAdapter that supports this handler"); }}//接口 ：具体的实现 有6个适配器public interface HandlerAdapter {handler 标记 boolean supports(Object handler); @Nullable ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception;@Deprecated long getLastModified(HttpServletRequest request, Object handler);}}
适配器到此结束；
桥接模式-结构化
代码分享
类图
/* * Package: com.example.demo.bridg * Type: Brand * Date: 2022-03-12 20:47 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.bridg;/ * 功能描述：为手机品牌做的接口 * * @author Songxianyang * @date 2022-03-12 20:47 */public interface Brand { / * 打电话 */ void call(); / * 上网 */ void net();}/* * Package: com.example.demo.bridg * Type: Flat * Date: 2022-03-12 20:55 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.bridg;/ * 功能描述：平板 手机 * * @author Songxianyang * @date 2022-03-12 20:55 */public class FlatPhone extends StylePhone { private String name = "平板:"; public FlatPhone(Brand brand) { super(brand); } @Override public void call() { System.out.println(name); super.call(); } @Override protected void net() { System.out.println(name); super.net(); }}/* * Package: com.example.demo.bridg * Type: FlipPhone * Date: 2022-03-12 20:55 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.bridg;/ * 功能描述：翻盖 手机 * * @author Songxianyang * @date 2022-03-12 20:55 */public class FlipPhone extends StylePhone { private String name = "翻盖:"; public FlipPhone(Brand brand) { super(brand); } @Override public void call() { System.out.println(name); super.call(); } @Override protected void net() { System.out.println(name); super.net(); }}/* * Package: com.example.demo.bridg * Type: XiaoMPhone * Date: 2022-03-12 20:49 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.bridg;/ * 功能描述：小米手机 * * @author Songxianyang * @date 2022-03-12 20:49 */public class HuaweiPhone implements Brand { @Override public void call() { System.out.println("Huawei手机打电话"); } @Override public void net() { System.out.println("Huawei手机上网"); }}/* * Package: com.example.demo.bridg * Type: StylePhone * Date: 2022-03-12 20:53 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.bridg;/ * 功能描述：手机样式 * * @author Songxianyang * @date 2022-03-12 20:53 */public abstract class StylePhone { private Brand brand; public StylePhone(Brand brand) { this.brand = brand; } // 开始搭桥 protected void call(){ brand.call(); } protected void net() { brand.net(); }}/* * Package: com.example.demo.bridg * Type: Test * Date: 2022-03-12 20:51 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.bridg;/ * 功能描述：桥接模式 ： 抽象类与接口分开 * * @author Songxianyang * @date 2022-03-12 20:51 */public class Test { public static void main(String[] args) { StylePhone flatPhone = new FlatPhone(new XiaoMiPhone()); flatPhone.call(); flatPhone.net(); System.out.println("----------------------"); StylePhone flipPhone = new FlipPhone(new XiaoMiPhone()); flipPhone.call(); flipPhone.net(); System.out.println("-----------------"); StylePhone huawei = new FlipPhone(new HuaweiPhone()); huawei.call(); huawei.net(); }}/* * Package: com.example.demo.bridg * Type: XiaoMPhone * Date: 2022-03-12 20:49 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.bridg;/ * 功能描述：小米手机 * * @author Songxianyang * @date 2022-03-12 20:49 */public class XiaoMiPhone implements Brand{ @Override public void call() { System.out.println("Xiaomi手机打电话"); } @Override public void net() { System.out.println("Xiaomi手机上网"); }}
jdbc源码分析
没有分析明白
桥接总结
装饰者设计模式
需求
代码结构
详细代码 展示
/* * Package: com.example.demo.design.decorator.master * Type: AmericanoCoffee * Date: 2022-03-13 15:08 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.decorator.master;/ * 功能描述：美式咖啡 * * @author Songxianyang * @date 2022-03-13 15:08 */public class AmericanoCoffee extends Coffee{ public AmericanoCoffee() { setName("美式咖啡"); setPrice(2.0f); }}/* * Package: com.example.demo.design.decorator.master * Type: ChinaCoffee * Date: 2022-03-13 15:12 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.decorator.master;/ * 功能描述：中国咖啡 * * @author Songxianyang * @date 2022-03-13 15:12 */public class ChinaCoffee extends Coffee{ public ChinaCoffee() { setName("中国咖啡"); setPrice(2.0f); }}/* * Package: com.example.demo.design.decorator.master * Type: Coffee * Date: 2022-03-13 15:07 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.decorator.master;/ * 功能描述： * * @author Songxianyang * @date 2022-03-13 15:07 */public class Coffee extends Drink { @Override float count() { return getPrice(); }}/* * Package: com.example.demo.design.decorator.master * Type: DecoratorSeasone * Date: 2022-03-13 15:14 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.decorator.master;/ * 功能描述： 装饰者 调料 * * @author Songxianyang * @date 2022-03-13 15:14 */public class DecoratorSeason extends Drink{ private Drink drink; public DecoratorSeason(Drink drink) { this.drink = drink; } @Override float count() { // getPrice 当前调料的钱 drink.count() 上一次计算的钱 return getPrice()+drink.count(); } @Override public void setName(String name) { super.setName(name+"&&"+drink.getName()); }}/* * Package: com.example.demo.design.decorator.master * Type: Drink * Date: 2022-03-13 15:01 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.decorator.master;/ * 功能描述： 饮料类 抽象起来 * * @author Songxianyang * @date 2022-03-13 15:01 */public abstract class Drink { private String name; private float price; / * 计算价格 * @return */ abstract float count(); public String getName() { return name; } public void setName(String name) { this.name = name; } public float getPrice() { return price; } public void setPrice(float price) { this.price = price; }}/* * Package: com.example.demo.design.decorator.master * Type: Milk * Date: 2022-03-13 15:21 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.decorator.master;/ * 功能描述：调料 牛奶 * * @author Songxianyang * @date 2022-03-13 15:21 */public class Milk extends DecoratorSeason{ public Milk(Drink drink) { super(drink); setName("调料 牛奶"); setPrice(1.0f); } }/* * Package: com.example.demo.design.decorator.master * Type: SoyBean * Date: 2022-03-13 15:23 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.decorator.master;/ * 功能描述：豆浆 * * @author Songxianyang * @date 2022-03-13 15:23 */public class SoyBean extends DecoratorSeason{ public SoyBean(Drink drink) { super(drink); setName("豆浆"); setPrice(2.0f); }}/* * Package: com.example.demo.design.decorator * Type: Test * Date: 2022-02-20 13:36 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.design.decorator.master;/ * 功能描述： * * @author Songxianyang * @date 2022-02-20 13:36 */public class Test { public static void main(String[] args) { //普通一杯 中国咖啡 Drink order = new ChinaCoffee(); System.out.println(order.getPrice()); // 中国咖啡+牛奶 order= new Milk(order); System.out.println("咖啡总价"+ order.count()); System.out.println(order.getName()); // 中国咖啡+豆浆 order=new SoyBean(order); System.out.println("咖啡总价"+ order.count()); System.out.println(order.getName()); // 中国咖啡+豆浆+豆浆 order=new SoyBean(order); System.out.println("咖啡总价"+ order.count()); System.out.println(order.getName()); }}测试截图
注意的点： 在装饰器类：DecoratorSeason 中两个的方法 。有说明
装饰器 挺绕的 面试经常问
IO 分析
/* * Package: com.example.demo.jdk * Type: Io * Date: 2022-03-15 22:25 * * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved. * * You may not use this file except in compliance with the License. */package com.example.demo.jdk;import java.io.DataInputStream;import java.io.FileInputStream;/ * 功能描述： * * @author Songxianyang * @date 2022-03-15 22:25 */public class Io { public static void main(String[] args) throws Exception { / * FilterInputStream 装饰器 * protected volatile InputStream in; 饮料 *DataInputStream 咖啡 */ DataInputStream dataInputStream = new DataInputStream(new FileInputStream("")); System.out.println(dataInputStream.read()); dataInputStream.close(); }}
