叨逼叨两句

1. 今天又了结一件事，好累，好爽。

2. 这几天在哥们家玩，更新内容不会断，但会相对少些了。

21-09：将文本反转

1. 流对象要尽量晚开早关

package com.test.demo001;  import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.util.ArrayList;  public class Demo009 {     public static void main(String[] args) throws IOException{         BufferedReader br = new BufferedReader(new FileReader("b.txt"));         ArrayList<String> list = new ArrayList<>();         String line;         while((line = br.readLine())!= null){             list.add(line);         }         br.close();                   BufferedWriter bw = new BufferedWriter(new FileWriter("c.txt"));         for (int i = list.size() - 1;i > 0; i--) {             bw.write(list.get(i));             bw.newLine();         }         bw.close();     } } 

21-10：LineNumberReader

1. getLineNumber

2. setLineNumber

package com.test.demo001;  import java.io.FileReader; import java.io.IOException; import java.io.LineNumberReader;  public class Demo009 {     public static void main(String[] args) throws IOException{         LineNumberReader lnr = new LineNumberReader(new FileReader("b.txt"));         String line;         lnr.setLineNumber(100);         while((line = lnr.readLine())!= null){             System.out.PRintln(lnr.getLineNumber()+":"+line);         }         lnr.close();     } } 

21-11: 装饰设计模式

步骤

1. 获取被装饰类的引用

2. 在构造方法中传入被装饰类的对象

3. 对原有的功能进行升级

优势

1. 装饰设计模式的耦合性比较低，被装饰的类的变化与装饰类的变化无关

package com.test.demo001;  import java.io.FileReader; import java.io.IOException; import java.io.LineNumberReader;  public class Demo009 {     public static void main(String[] args) throws IOException{         Student1 stu1 = new Student1();         HeiMaStudent hms = new HeiMaStudent(stu1);         hms.code();              } }  interface Coder {     public void code(); }  class Student1 implements Coder {     public void code() {         System.out.println("javase");         System.out.println("javaweb");     } }  class HeiMaStudent implements Coder {     private Student1 s ;          public HeiMaStudent(Student1 s){         this.s = s;     }          @override     public void code() {         s.code();         System.out.println("大数据");         System.out.println("AI");     }      }