15.复制文本文件的5种方式

复制文本文件的5种方式

• A:利用基本流一次读写一个字符
• B:利用基本流一次读写一个字符数组
• C:利用缓冲流一次读写一个字符
• D:利用缓冲流一次读写一个字符数组
• E:利用缓冲流的特有方法一次读写一个字符串

package com.itheima_06;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

/*
 *  复制文本文件(5种方式)
 *  
 *  数据源:
 *      FileWriterDemo.java
 *  目的地：
 *      Copy.java
*/      
public class CopyFileTest {
    public static void main(String[] args) throws IOException {
        /*
        method1("FileWriterDemo.java","Copy.java");
        method2("FileWriterDemo.java","Copy.java");
        method3("FileWriterDemo.java","Copy.java");
        method4("FileWriterDemo.java","Copy.java");
        method5("FileWriterDemo.java","Copy.java");
        */
        
        String srcFileName = "FileWriterDemo.java";
        String destFileName = "Copy.java";
        
//      method1(srcFileName,destFileName);
//      method2(srcFileName,destFileName);
//      method3(srcFileName,destFileName);
//      method4(srcFileName,destFileName);
        method5(srcFileName,destFileName);
    }
    
    //基本流一次读写一个字符
    public static void method1(String srcFileName,String destFileName) throws IOException {
        //创建输入流对象
        FileReader fr = new FileReader(srcFileName);
        //创建输出流对象
        FileWriter fw = new FileWriter(destFileName);
        
        //一次读写一个字符
        int ch;
        while((ch = fr.read())!=-1) {
            fw.write(ch);
        }
        
        //释放资源
        fw.close();
        fr.close();
    }
    
    //基本流一次读写一个字符数组
    public static void method2(String srcFileName,String destFileName) throws IOException {
        //创建输入流对象
        FileReader fr = new FileReader(srcFileName);
        //创建输出流对象
        FileWriter fw = new FileWriter(destFileName);
        
        char[] chs = new char[1024];
        int len;
        while((len = fr.read(chs)) != -1) {
            fw.write(chs,0,len);
        }
        
        //释放资源
        fw.close();
        fr.close();
    }
    
    //缓冲流一次读写一个字符
    public static void method3(String srcFileName,String destFileName) throws IOException {
        //创建缓冲流输入对象
        BufferedReader br = new BufferedReader(new FileReader(srcFileName));
        //创建缓冲流输出对象
        BufferedWriter bw = new BufferedWriter(new FileWriter(destFileName));
        
        //一次读写一个字符
        int ch;
        while((ch = br.read()) != -1) {
            bw.write(ch);
        }
        
        //释放资源
        bw.close();
        br.close();
    }
    
    //缓冲流一次读写一个字符数组
    public static void method4(String srcFileName,String destFileName) throws IOException {
        //创建输入流对象
        BufferedReader br = new BufferedReader(new FileReader(srcFileName));
        //创建输出流对象
        BufferedWriter bw = new BufferedWriter(new FileWriter(destFileName));
        
        //一次读写一个字符数组
        char[] chs = new char[1024];
        int len;
        while((len = br.read(chs))!=-1) {
            bw.write(chs,0,len);
        }
        
        //释放资源
        bw.close();
        br.close();
    }
    
    //缓冲流一次读写一个字符串(推荐)
    public static void method5(String srcFileName,String destFileName) throws IOException {
        //创建输入流对象
        BufferedReader br = new BufferedReader(new FileReader(srcFileName));
        //创建输出流对象
        BufferedWriter bw = new BufferedWriter(new FileWriter(destFileName));
        
        //一次读写一个字符串
        String line;
        while((line = br.readLine())!=null) {
            bw.write(line);
            bw.newLine();
            bw.flush();
        }
        
        //释放资源
        bw.close();
        br.close();
        
    }
}