- 知识的海洋里,没有地图,你就会迷路,而脑图就是这个地图。
将排序后的结果按行存储,按行存储,按行存储(重要事情说三遍,须要换行)到itcast_copy.txt文件中。java
逻辑在Demo类的main函数中实现;
例如itcast.txt中按行存储了 9,2,5,2,6,5,4,9
打印的结果:函数
第一行--> 初始: 9 2 5 2 6 5 4 9 第二行--> 去重: 9 2 5 6 4 第三行--> 排序: 2 4 5 6 9
package com.heima_IO; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.util.TreeSet; public class Demo1 { public static void main(String[] args) throws IOException { BufferedReader br = new BufferedReader(new FileReader(new File("itcast.txt"))); BufferedWriter bw = new BufferedWriter(new FileWriter(new File("itcast_copy.txt"))); String line; TreeSet<Integer> ts = new TreeSet<>(); String startStr = "初始:"; while((line = br.readLine()) != null) { ts.add(Integer.parseInt(line)); startStr += line + " "; } startStr = startStr.trim(); String distinctStr = "去重: "; String sortStr = "排序: "; for(int i : ts) { distinctStr += i + " "; sortStr += i + " "; bw.write("" + i); bw.newLine(); } br.close(); bw.close(); System.out.println(startStr); System.out.println(distinctStr); System.out.println(sortStr); } }