Java-字符与字节的区别

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class bufferedReader {
public static void main(String[] args) {
//      copyFileBuffer();
//      copyMp3();
//ASCII GB2312 GBK
FileCopyMp3();
}
//二进制文件必须采用字节流
private static void FileCopyMp3() {
//文件复制，从一个文件读出，写到另一个文件中
String dir1="c:\\";
String dir2="c:\\b\\";
String fileName="a.mp3";
FileInputStream in=null;
FileOutputStream out =null;
try {
in= new FileInputStream(dir1+fileName);
out =new FileOutputStream(dir2+fileName);
byte buf[]=new byte[512];
int len=-1;
while((len=in.read(buf))!=-1){
out.write(buf,0,len);//读了多少写多少
}
in.close();
out.close();
} catch (IOException e) {
e.printStackTrace();//文件找不到抛异常
}finally{//能把数据关闭
try {
if(in!=null){
in.close();
}
if(out!=null){
out.close();
}
} catch (IOException e) {
throw new RuntimeException("文件关闭失败，数据可能关闭失败");
}

}
}

//字符流。
private static void copyMp3() {

FileReader fr=null;
FileWriter fw=null;
char buf[]=new char[20];
try {
fr=new FileReader("c:\\a.mp3");
fw=new FileWriter("c:\\b.mp3");
int len=-1;
while((len=fr.read(buf))!=-1){
fw.write(buf,0,len);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
if(fr!=null){
fr.close();
}
if(fw!=null){
fw.close();
}
} catch (IOException e) {
throw new RuntimeException("file cant close");
}
}

}
//字符流。字节缓冲：一次读一个字节太慢,字符流快一点
private static void copyFileBuffer() {

try {
BufferedReader br=new BufferedReader(new FileReader("d:\\a.txt"));
BufferedWriter bw=new BufferedWriter(new FileWriter("d:\\c.txt"));
String line=null;
while((line=br.readLine())!=null){
bw.write(line);
//写入换行符的方法
bw.newLine();//1。向文件写入一个换行符，仅适用于BufferedWriter
//              bw.write(System.getProperty("line.separator"));//2。兼容两种
//              bw.write("\r\n");//3。wodows
//              bw.write("\n");//3.linux
}
br.close();
bw.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}