java 字符转换流

package cn.sasa.demo4;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class OutputStreamWriterDemo {
    public static void main(String[] args) throws IOException {
        /**
         * FileWriter 不能指定字符编码
         *
         * 用OutputStreamWriter
         * 将字符流转成字节流
         *
         */
//        writeGBK();
        //writeUTF8();
        //readGBK();
        readUTF8();
    }

    static void writeGBK() throws IOException {
        //1、创建一个FileOutputStream，绑定目的
        FileOutputStream output = new FileOutputStream("d:/sasa/test1225.txt");

        //2、创建一个OutputStreamWriter，指定字符编码，
        //构造函数的第二个字符串参数指定字符编码，不写默认是系统的默认编码GBK
        OutputStreamWriter writer = new OutputStreamWriter(output);

        //3、调用write
        writer.write("你好");
        writer.flush();
        writer.close();
    }

    static void writeUTF8() throws IOException {
        FileOutputStream output = new FileOutputStream("d:\\sasa\\utf.txt");
        OutputStreamWriter writer = new OutputStreamWriter(output, "UTF-8");
        writer.write("啦啦啦");
        writer.flush();
        writer.write("你好");
        writer.flush();
        writer.close();
    }

    static void readGBK() throws IOException {
        FileInputStream input = new FileInputStream("d:\\sasa\\test1225.txt");
        InputStreamReader reader = new InputStreamReader(input);
        char[] charArr = new char[1024];
        @SuppressWarnings("unused")
        int len = 0;
        while((len = reader.read(charArr)) != -1) {
            System.out.print(new String(charArr));
        }
        reader.close();
    }

    static void readUTF8() throws IOException {
        FileInputStream input = new FileInputStream("d:\\sasa\\utf.txt");
        InputStreamReader reader = new InputStreamReader(input , "UTF-8");
        char[] charArr = new char[1024];
        @SuppressWarnings("unused")
        int len = 0;
        while((len = reader.read(charArr)) != -1) {
            System.out.print(new String(charArr));
        }
        reader.close();
    }
}