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();	}	} }