java io流

import java.io.*;/*io流細節@  blog.csdn.net/ljfbest*/class Test {public static void main(String[] args) throws IOException {/*FileWriter fw=new FileWriter(new File("a.txt"),true);//在windows中，一個換行相當於\r\n兩個字元,而linux中則是\nfw.write("ssss\r\n");//勿忘重新整理緩衝區，不然寫不到a.txt中，fr.close()前也會自動重新整理一次fw.flush();*/FileReader fr=new FileReader("a.txt");char[] ch1=new char[3];/*a.txt：1. abcde--->abcdec （關鍵理解原理） 2. abc (此處一個換行，在windows中相當於兩個字元，故輸出以下)    e    --->abc         e*/while((fr.read(ch1))!=-1)System.out.print(ch1);//System.out.print(new String (buf,0,num));fr.close();}}import java.io.*;/*字元流的緩衝區 BufferedWriter,BufferedReader*/class Test {public static void main(String[] args) throws IOException {/*FileWriter fw=new FileWriter("a.txt",true);BufferedWriter bf=new BufferedWriter(fw);bf.write("ccc");bf.newLine();//輸入一個分行符號，windows下是\r\n,linux下是\nbf.write("aaa");bf.flush();bf.close();*/BufferedWriter bw=new BufferedWriter(new FileWriter("b.txt"));BufferedReader br=new BufferedReader(new FileReader("Test.java"));String line=null;while((line=br.readLine())!=null){bw.write(line);bw.newLine();bw.flush();}bw.close();br.close();}}import java.io.*;/*字元流的緩衝區 BufferedWriter,BufferedReader*/class Test {public static void main(String[] args) throws IOException {/*FileOutputStream fs=new FileOutputStream("c.txt");fs.write("你好！".getBytes());//必須要轉化為位元組數組//此時不需要重新整理，flush()fs.close();*/FileInputStream fi=new FileInputStream("c.txt");/*int ch;while((ch=fi.read())!=-1)System.out.println((char)ch);        */byte[] by=new byte[1024];int len;while((len=fi.read(by))!=-1)System.out.println(new String(by,0,len));fi.close();}}import java.io.*;import java.util.*;class Test {public static void main(String[] args) throws IOException {/* // 轉換流：將位元組流轉成字元流再使用緩衝區的readLine()InputStream in=System.in;InputStreamReader is=new InputStreamReader(in);//轉換流BufferedReader bf=new BufferedReader(is);String line=null;while((line=bf.readLine())!=null)System.out.println(line);*//*//PrinterWriter  PrinterStreamBufferedReader bf=new BufferedReader(new InputStreamReader(System.in));//此處不用BufferedWriter改用PrintWriter;如果為 true，則 println、printf 或 format 方法將重新整理輸出緩衝區PrintWriter out=new PrintWriter(System.out,true);//此處寫到控制台上,重新整理只對流起作用//PrintWriter out=new PrintWriter(new BufferedWriter(new FileWriter("a.txt")));//此處要轉換成流，才能自動重新整理String line=null;while((line=bf.readLine())!=null)out.println(line);out.close();bf.close();*//*DataInputStream in=new DataInputStream(System.in);int n=in.readInt();System.out.println(n);in.close();//注意：DataInputStream與DataOutputStream必須成對出現*//*BufferedReader bf=new BufferedReader(new InputStreamReader(System.in));String s=bf.readLine();byte[] b=s.getBytes("GBK");//編碼    省略時系統預設的String s1=new String(b,"GBK");///解碼  省略時系統預設的System.out.println(s1);//System.out.println(Arrays.toString(b));*/BufferedInputStream bf=new BufferedInputStream(System.in);byte[] b=new byte[10];bf.read(b);String s=new String(b);System.out.println(s);}}