IO字符流五种方式复制文件

  1 package com.qyh.io;
  2 
  3 import java.io.BufferedReader;
  4 import java.io.BufferedWriter;
  5 import java.io.FileReader;
  6 import java.io.FileWriter;
  7 import java.io.IOException;
  8 
  9 /*
 10  * 字符流复制文本文件
 11  * 
 12  * 
 13  */
 14 
 15 public class CopyTextDemo {
 16     public static void main(String[] args) throws IOException {
 17         method1("a.txt", "b.txt");
 18         method2("a.txt", "c.txt");
 19         method3("a.txt", "d.txt");
 20         method4("a.txt", "e.txt");
 21         method5("a.txt", "f.txt");
 22     }
 23     
 24     //高效字符流一次读取一行
 25     private static void method5(String srcString, String destString) throws IOException {
 26         BufferedReader br = new BufferedReader(new FileReader(srcString));
 27         BufferedWriter bw = new BufferedWriter(new FileWriter(destString));
 28         
 29         String line = null;
 30         while((line=br.readLine())!=null) {
 31             bw.write(line);
 32             bw.newLine();
 33             bw.flush();
 34         }
 35         bw.close();
 36         br.close();
 37         
 38     }
 39 
 40     // 高效字符流一次读取一个字符数组
 41     private static void method4(String srcString, String destString) throws IOException {
 42         BufferedReader br = new BufferedReader(new FileReader(srcString));
 43         BufferedWriter bw = new BufferedWriter(new FileWriter(destString));
 44 
 45         char[] ch = new char[1024];
 46         int len = 0;
 47         while ((len = br.read(ch)) != -1) {
 48             bw.write(ch, 0, len);
 49             bw.flush();
 50         }
 51         bw.close();
 52         br.close();
 53 
 54     }
 55 
 56     // 高效字符流一次读一个字符
 57     private static void method3(String srcString, String destString) throws IOException {
 58         BufferedReader br = new BufferedReader(new FileReader(srcString));
 59         BufferedWriter bw = new BufferedWriter(new FileWriter(destString));
 60 
 61         int ch = 0;
 62         while ((ch = br.read()) != -1) {
 63             bw.write(ch);
 64         }
 65         bw.close();
 66         br.close();
 67 
 68     }
 69 
 70     // 一次读取一个字符数组
 71     private static void method2(String srcString, String destString) throws IOException {
 72         FileReader fr = new FileReader(srcString);
 73         FileWriter fw = new FileWriter(destString);
 74 
 75         char[] ch = new char[1024];
 76         int len = 0;
 77         while ((len = fr.read(ch)) != -1) {
 78             fw.write(ch, 0, len);
 79             fw.flush();
 80         }
 81         fw.close();
 82         fr.close();
 83 
 84     }
 85 
 86     // 一次读取一个字符
 87     private static void method1(String srcString, String destString) throws IOException {
 88         // 封装数据源
 89         FileReader fr = new FileReader(srcString);
 90         // 封装目的地
 91         FileWriter fw = new FileWriter(destString);
 92         // 读写数据
 93         int ch = 0;
 94         while ((ch = fr.read()) != -1) {
 95             fw.write(ch);
 96         }
 97         // 释放资源
 98         fw.close();
 99         fr.close();
100 
101     }
102 
103 }
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