JAVA學習筆記(三十二)- 字元流 FileReader & FileWriter

標籤：字元流   filereader   

標題

import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.io.Reader;import java.io.Writer;/* * FileReader/FileWriter類 * 檔案字元輸入輸出資料流 */public class Test03 {    public static void main(String[] args) throws IOException {        test3();    }    // 檔案字元輸入資料流    public static void test1() throws IOException {        Reader reader = new FileReader("D:\\Java\\hello.txt");        // 每次讀取一個字元        int data = reader.read();// 返回一個int類型的字元值        while (data != -1) {            System.out.println((char) data);            data = reader.read();        }        reader.close();    }    // 檔案字元輸出資料流    public static void test2() throws IOException {        Writer writer = new FileWriter("D:\\Java\\hello.txt", true);        writer.write("餘書磊");        writer.flush();        System.out.println("使用字元輸出資料流寫入成功！");        writer.close();    }    // 檔案複製    public static void test3() throws IOException {        Reader reader = new FileReader("D:\\Java\\hello.txt");        Writer writer = new FileWriter("D:\\Java\\hello_bak.txt");        //方式一：每次複製一個字元        int data = reader.read();        while (data != -1) {            writer.write(data);            data = reader.read();        }        //方式二：每次複製一個字元數組        char[] buffer=new char[10];        int num=reader.read(buffer);//返回實際讀取的長度        while(num!=-1){            writer.write(buffer, 0, num);            num=reader.read(buffer);        }        //方式三：將讀取的字元拼接到字串中，再寫入        StringBuffer sb=new StringBuffer();        int data = reader.read();        while (data != -1) {            sb.append((char)data);            data = reader.read();        }        writer.write(sb.toString());        writer.flush();        System.out.println("檔案複製成功！");        writer.close();        reader.close();    }    /*     *  字元流無法複製二進位檔案，位元組流可以     */    public static void test4() throws IOException {        BufferedInputStream bis=new BufferedInputStream(new FileInputStream("D:\\Java\\ascii.jpg"));        BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream("D:\\Java\\ascii_bak.jpg"));        int data = bis.read();        while (data != -1) {            bos.write(data);            data = bis.read();        }        bos.flush();        System.out.println("檔案複製成功！");        bos.close();        bis.close();    }}

JAVA學習筆記(三十二)- 字元流 FileReader & FileWriter