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;}@Overridepublic void code() {s.code();System.out.println("大数据");System.out.println("AI");}}