Java_基础—使用指定的码表读写字符

图解转换流

package com.soar.chario;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;

public class Demo7_TransIO {
/*
    * FileReader是使用默认码表读取文件, 如果需要使用指定码表读取, 那么可以使用InputStreamReader(字节流,编码表)
    * FileWriter是使用默认码表写出文件, 如果需要使用指定码表写出, 那么可以使用OutputStreamWriter(字节流,编码表)
    *********************************************
    BufferedReader br =                                     //高效的用指定的编码表读
        new BufferedReader(new InputStreamReader(new FileInputStream("UTF-8.txt"), "UTF-8"));
    BufferedWriter bw =                                     //高效的用指定的编码表写
        new BufferedWriter(new OutputStreamWriter(new FileOutputStream("GBK.txt"), "GBK"));
        int ch;
        while((ch = br.read()) != -1) {
            bw.write(ch);
        }

        br.close();
        bw.close();
*/

    public static void main(String[] args) throws IOException {
        //defaultRead();
        //requireRead();

        BufferedReader br =             //更高效的读
        new BufferedReader(new InputStreamReader(new FileInputStream("utf-8.txt"),"utf-8"));
        BufferedWriter bw =             //更高效的写
        new BufferedWriter(new OutputStreamWriter(new FileOutputStream("gbk.txt"),"gbk"));

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

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

    private static void requireRead() throws UnsupportedEncodingException,
            FileNotFoundException, IOException {
        InputStreamReader isr = new InputStreamReader(new FileInputStream("utf-8.txt"),"utf-8");    //指定码表读字符
        OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream("gbk.txt"),"gbk");     //指定码表写字符

        int c;
        while((c = isr.read()) != -1){
            osw.write(c);
        }

        isr.close();
        osw.close();
    }

    private static void defaultRead() throws FileNotFoundException, IOException {
        //用默认编码表读写，出现乱码
        FileReader fr = new FileReader("utf-8.txt");
        FileWriter fw = new FileWriter("gbk.txt");

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

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

}