转换流的介绍

InputStreamReader与OutputStreamWriter 也是处理流 

package TransformStream;

import org.junit.Test;

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

public class InputStreamReaderTest {
    @Test
    public void test1() throws IOException {
        FileInputStream fis = new FileInputStream("hello2.txt");
//        使用默认的字符集 将 字节流的数据转换(在IDEA中为默认UTF-8)
        InputStreamReader isr = new InputStreamReader(fis);

//        指定字符集 将 字节流的数据转换
//        InputStreamReader isr = new InputStreamReader(fis,"gbk");



        char[] buffer = new char[5];
        int len ;
        while((len = isr.read(buffer))!=-1){
            String str= new String(buffer);
            System.out.print(buffer);
        }
//      转换流也是处理流，所以只需要关闭外层
        isr.close();
    }
}

OutputStreamWriter

//    OutputStreamWriter
    @Test
    public void test2() throws IOException {
        FileReader fr = new FileReader("hello2.txt");
        FileOutputStream fos = new FileOutputStream("hello3.txt");

        OutputStreamWriter osw = new OutputStreamWriter(fos,"gbk");

        char[] buffer = new char[5];
        int len;
        while((len = fr.read(buffer))!=-1){
            osw.write(buffer,0,len);
        }

        fr.close();
        osw.close();
    }