IO流--五种方式复制文本文件

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

/*
 * 数据源：
 *         a.txt -- FileReader -- BufferdReader
 * 目的地：
 *         b.txt -- FileWriter -- BufferedWriter
 * 推荐使用第五种
 */
public class CopyFileDemo {
    public static void main(String[] args) throws IOException {
        String srcString = "a.txt";
        String destString = "b.txt";
        // method1(srcString, destString);
        // method2(srcString, destString);
        // method3(srcString, destString);
        // method4(srcString, destString);
        method5(srcString, destString);
    }

    // 字符缓冲流一次读写一个字符串
    private static void method5(String srcString, String destString) throws IOException {
        BufferedReader br = new BufferedReader(new FileReader(srcString));
        BufferedWriter bw = new BufferedWriter(new FileWriter(destString));

        String line = null;
        while ((line = br.readLine()) != null) {
            bw.write(line);
            bw.newLine();
            bw.flush();
        }

        bw.close();
        br.close();
    }

    // 字符缓冲流一次读写一个字符数组
    private static void method4(String srcString, String destString) throws IOException {
        BufferedReader br = new BufferedReader(new FileReader(srcString));
        BufferedWriter bw = new BufferedWriter(new FileWriter(destString));

        char[] chs = new char[1024];
        int len = 0;
        while ((len = br.read(chs)) != -1) {
            bw.write(chs, 0, len);
        }

        bw.close();
        br.close();
    }

    // 字符缓冲流一次读写一个字符
    private static void method3(String srcString, String destString) throws IOException {
        BufferedReader br = new BufferedReader(new FileReader(srcString));
        BufferedWriter bw = new BufferedWriter(new FileWriter(destString));

        int ch = 0;
        while ((ch = br.read()) != -1) {
            bw.write(ch);
        }

        bw.close();
        br.close();
    }

    // 基本字符流一次读写一个字符数组
    private static void method2(String srcString, String destString) throws IOException {
        FileReader fr = new FileReader(srcString);
        FileWriter fw = new FileWriter(destString);

        char[] chs = new char[1024];
        int len = 0;
        while ((len = fr.read(chs)) != -1) {
            fw.write(chs, 0, len);
        }

        fw.close();
        fr.close();
    }

    // 基本字符流一次读写一个字符
    private static void method1(String srcString, String destString) throws IOException {
        FileReader fr = new FileReader(srcString);
        FileWriter fw = new FileWriter(destString);

        int ch = 0;
        while ((ch = fr.read()) != -1) {
            fw.write(ch);
        }

        fw.close();
        fr.close();
    }
}