Java緩沖字符輸入輸出流

字符緩沖流

默認有8192字符大小的緩沖區(qū)

package com.wkcto.chapter06.readerwriter;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.FilterWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;

/**
 * BufferedReader/BufferedWriter
 * 	字符緩沖流, 對其他字符流進行緩沖, 默認緩沖區(qū)大小為8192個字符
 * @author 蛙課網(wǎng)
 *
 */
public class Test05 {

	public static void main(String[] args) throws IOException {
		//1) 使用緩沖字符流讀取文件的內(nèi)容
//		readData();
		//2) 使用緩沖字符流保存數(shù)據(jù)到文件中
		writeData();
	}
	
	//2) 使用緩沖字符流保存數(shù)據(jù)到文件中
	private static void writeData() throws IOException {
		FileWriter  fw = new FileWriter("d:/def.txt");
		BufferedWriter bw = new BufferedWriter(fw);
		
		//把數(shù)組保存到緩沖流的緩沖區(qū)中
		bw.write("hello");
		bw.newLine();
		bw.write("wkcto");
		
		//從鍵盤上輸入數(shù)據(jù)保存到文件中
//		Scanner sc = new Scanner(System.in);
		//System.in代表系統(tǒng)的標準輸入設(shè)備,即鍵盤,  System類的in字段是InputStream字節(jié)流
//		String line = sc.nextLine(); 		//從鍵盤上讀取一行
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String line = br.readLine();
		while( line.length() > 0 ){
			bw.write(line);
			bw.newLine();
//			line = sc.nextLine();
			line = br.readLine();
		}
		
		bw.close(); 		//關(guān)閉緩沖流時,會把緩沖區(qū)的數(shù)據(jù)保存到文件中
		
	}
	//1) 使用緩沖字符流讀取文件的內(nèi)容
	private static void readData() throws IOException {
		//創(chuàng)建字符流, d:/test.java文件, 該文件編碼為utf-8,與當(dāng)前環(huán)境編碼一致
//		FileReader fr = new FileReader("d:/test.java");
		//創(chuàng)建字符流, d:/test01.java文件, 該文件編碼為GBK,與當(dāng)前環(huán)境編碼不一致
		InputStreamReader fr = new InputStreamReader(new FileInputStream("d:/test01.java"), "GBK");
		//對字符流進行緩沖
		BufferedReader br = new BufferedReader(fr);
		
		//從緩沖字符流中讀取數(shù)據(jù), readLine()從輸入緩沖字符流中讀取一行, 讀到文件末尾返回null
		String line = br.readLine();
		while( line != null ){
			System.out.println( line);
			line = br.readLine();
		}
		
		br.close();
	}

}