字符流和字节流的主要区别：
1.字节流读取的时候，读到一个字节就返回一个字节； 字符流使用了字节流读到一个或多个字节（中文对应的字节数是两个，在UTF-8码表中是3个字节）时。先去查指定的编码表，将查到的字符返回。
2.字节流可以处理所有类型数据，如：图片，MP3，AVI视频文件，而字符流只能处理字符数据。只要是处理纯文本数据，就要优先考虑使用字符流，除此之外都用字节流。
字节流：
1、通过字节流写数据
code：
package com.test; import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException; public class WriteByteStream { public static void main(String[] args) {
try { FileOutputStream fos = new FileOutputStream("textw.txt");
String outString = "write 123456写出数据";
byte output[] = outString.getBytes("UTF-8");
fos.write(output);
fos.close(); } catch (FileNotFoundException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} }
2、通过字节流读数据：
code：
package com.test; import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.UnsupportedEncodingException; public class ReadByteStream { public static void main(String[] args) {
try {
FileInputStream fis = new FileInputStream("text.txt");
byte input[] = new byte[];
fis.read(input); String inputString = new String(input, "UTF-8");
System.out.println(inputString);
fis.close(); } catch (FileNotFoundException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} } }
3、使用字节流读写数据
code：
package com.test; import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException; public class CopyByByteStream { public static void main(String[] args) {
try { FileInputStream fis = new FileInputStream("movie.mp4");
FileOutputStream fos = new FileOutputStream("movie_new.mp4"); byte input[] = new byte[];
long before = System.currentTimeMillis();
int count = ;
while (fis.read(input) != -) {
fos.write(input);
count++;
}
fos.flush();
fis.close();
fos.close();
System.out.println(System.currentTimeMillis()-before+"ms");
System.out.println("done"); } catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} }
4、使用带缓冲的字节流读写数据（字节流模板）
code：
package com.test;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException; public class ReadByBufferedByteStream { public static void main(String[] args) {
try { FileInputStream fis = new FileInputStream("movie.mp4");
BufferedInputStream bis = new BufferedInputStream(fis,);
FileOutputStream fos = new FileOutputStream("moive_new.mp4");
BufferedOutputStream bos = new BufferedOutputStream(fos,);
//大型文件对应的数组可以大一些，小文件对应的数组小一些
byte input[] = new byte[];
int count = ;
long before = System.currentTimeMillis();
while (bis.read(input) != -) {
bos.write(input);
count++;
}
bos.flush();
bis.close();
fis.close();
bos.close();
fos.close();
System.out.println(System.currentTimeMillis()-before+"ms");
System.out.println("读取了："+count+"次"); } catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} }
字符流：
1、使用字符流读写数据
code：
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException; public class RWByCharStream { public static void main(String[] args) {
try { //File file = new File("java.txt");
FileInputStream fis = new FileInputStream("java.txt");
FileOutputStream fos = new FileOutputStream("java_new.txt");
InputStreamReader isr = new InputStreamReader(fis, "UTF-8");
OutputStreamWriter osw = new OutputStreamWriter(fos, "UTF-8");
char input[] = new char[];
int l = ;
while ((l = isr.read(input)) != -) {
//String inputString = new String(input,0,l);
osw.write(input,,l);
}
isr.close();
fis.close();
osw.close();
fos.close();
System.out.println("done"); } catch (FileNotFoundException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} } }
2、使用带有缓冲的字符流读写数据（字符流模板）
code：
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException; public class RWByBufferedCharStream { public static void main(String[] args) {
try { //File file = new File("java.txt");
FileInputStream fis = new FileInputStream("java.txt");
FileOutputStream fos = new FileOutputStream("java_new_buff.txt");
InputStreamReader isr = new InputStreamReader(fis, "UTF-8");
OutputStreamWriter osw = new OutputStreamWriter(fos, "UTF-8"); BufferedReader br = new BufferedReader(isr);
//BufferedWriter bw = new BufferedWriter(osw);
PrintWriter pw = new PrintWriter(osw,true); String input;
while ((input = br.readLine()) != null) {
//bw.write(input);
pw.println(input);
}
br.close();
//bw.flush();bw.close();
pw.close();
isr.close();
fis.close();
osw.close();
fos.close();
System.out.println("done"); } catch (FileNotFoundException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} }