Java IO流之字符缓冲流实例详解

 /字符输入缓冲流 private static void charReader() { //目标文件 File file = new File("F:\\javatest\\lemon1.txt"); try { //字符流 Reader reader = new FileReader(file); //为字符流提供缓冲，已达到高效读取的目的 BufferedReader bufr = new BufferedReader(reader); char[] chars = new char[1024]; int len = -1; while((len = bufr.read(chars)) != -1) { System.out.println(new String(chars,0,len)); } bufr.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } 

 //字符输出缓存流 private static void charWriter() { //目标文件 File file = new File("F:\\javatest\\lemon1.txt"); try { //字符流 Writer writer = new FileWriter(file,true);//追加 //为字符流提供缓冲，已达到高效读取的目的 BufferedWriter bufr = new BufferedWriter(writer); bufr.write("这里是字符缓冲流\r\n"); bufr.flush(); bufr.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } 

 package com.lemon; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; 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.InputStream; import java.io.OutputStream; import java.io.Reader; import java.io.Writer; /** * 缓存的目的： * 解决在写入文件操作时，频繁的操作文件所带来的性能降低问题 * BufferedOutputStream内部默认的缓存大小是8kb，每次写入时存储到缓存中的byte数组中，当数组存满时，会把数组中的数据写入文件 * 并且缓存下标归零 * * 字符流： * 1、加入字符缓存流，增强读取功能（readLine） * 2、更高效的读取数据 * FileReader：内部使用InputStreamReader，解码过程，byte->char，默认缓存大小为8k * BufferReader：默认缓存大小为8k，但可以手动指定缓存大小，把数据读取到缓存中，减少每次转换过程，效率更高 * BufferedWriter：同上 * @author lemonSun * * 2019年5月4日下午8:12:53 */ public class BufferStreamDemo { public static void main(String[] args) { //	byteWriter(); //	byteReader(); //		byteReader1(); //		charReader(); charWriter(); } //字符输出缓存流 private static void charWriter() { //目标文件 File file = new File("F:\\javatest\\lemon1.txt"); try { //字符流 Writer writer = new FileWriter(file,true);//追加 //为字符流提供缓冲，已达到高效读取的目的 BufferedWriter bufr = new BufferedWriter(writer); bufr.write("这里是字符缓冲流\r\n"); bufr.flush(); bufr.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } //字符输入缓存流 private static void charReader() { //目标文件 File file = new File("F:\\javatest\\lemon1.txt"); try { //字符流 Reader reader = new FileReader(file); //为字符流提供缓冲，已达到高效读取的目的 BufferedReader bufr = new BufferedReader(reader); char[] chars = new char[1024]; int len = -1; while((len = bufr.read(chars)) != -1) { System.out.println(new String(chars,0,len)); } bufr.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } //缓存流输入 不用关闭 try自动关闭 必须实现Closeable接口 private static void byteReader1(){ //目标文件 File file = new File("F:\\javatest\\lemon1.txt"); //buf作用域在try大括号里面多条语句try(;)，;隔开 try(BufferedInputStream buf = new BufferedInputStream(new FileInputStream(file))) { byte[] bytes = new byte[1024]; int len = -1; while((len = buf.read(bytes)) != -1) { System.out.println(new String(bytes,0,len)); } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } //缓存流输入 private static void byteReader(){ //目标文件 File file = new File("F:\\javatest\\lemon1.txt"); try { //字节输出流 InputStream in = new FileInputStream(file); //字节缓冲流 BufferedInputStream buf = new BufferedInputStream(in); byte[] bytes = new byte[1024]; int len = -1; while((len = buf.read(bytes)) != -1) { System.out.println(new String(bytes,0,len)); } buf.close();//自动关闭 in.close } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } //缓存流输出 private static void byteWriter(){ //目标文件 File file = new File("F:\\javatest\\lemon1.txt"); try { //字节输出流 OutputStream out = new FileOutputStream(file,true); //缓冲流 BufferedOutputStream buf = new BufferedOutputStream(out); //内容 String info = "这里是缓冲流\r\n"; //写入 buf.write(info.getBytes()); buf.close(); //jdk1.7以后自动关闭 out //	out.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } }