IO流(複製文字檔案的5種方式案例(用字元流)
阿新 • • 發佈:2019-01-22
package cn.itcast_01; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; /* * 複製文字檔案 * * 分析: * 複製資料,如果我們知道用記事本開啟並能夠讀懂,就用字元流,否則用位元組流。 * 通過該原理,我們知道我們應該採用字元流更方便一些。 * 而字元流有5種方式,所以做這個題目我們有5種方式。推薦掌握第5種。 * 資料來源: * c:\\a.txt -- FileReader -- BufferdReader * 目的地: * d:\\b.txt -- FileWriter -- BufferedWriter */ public class CopyFileDemo { public static void main(String[] args) throws IOException { String srcString = "c:\\a.txt"; String destString = "d:\\b.txt"; // method1(srcString, destString); // method2(srcString, destString); // method3(srcString, destString); // method4(srcString, destString); method5(srcString, destString); } // 字元緩衝流一次讀寫一個字串 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(); } // 字元緩衝流一次讀寫一個字元陣列 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(); } // 字元緩衝流一次讀寫一個字元 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(); } // 基本字元流一次讀寫一個字元陣列 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(); } // 基本字元流一次讀寫一個字元 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(); } }