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();		}			} }