java 檔案讀寫

標籤：and   int   void   write   class   tput   get   寫入檔案   buffere   

import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.DataInputStream;import java.io.DataOutputStream;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.OutputStream;import java.nio.CharBuffer;import java.util.ArrayList;import java.util.List;public class filedemo {public static void main(String[] args) {File file=new File("c:\\22ssssssssss.txt");try {if(!file.exists()){file.createNewFile();FileOutputStream fileOutputStream=new FileOutputStream(file);DataOutputStream fDataOutputStream=new DataOutputStream(fileOutputStream);//fDataOutputStream.write("sfs哈d".getBytes());fDataOutputStream.writeUTF("\nx哈哈");fDataOutputStream.close();fileOutputStream.close();}else {//注意1：一般情況下在讀入時盡量按照寫入時的格式進行讀取，//否則有可能會出現顯示亂碼或程式出現異常。//如首先寫入檔案用的是writeUTF()，在讀取的時候如果不是用readUTF()就會出現亂碼，//如果readUTF()讀取的內容不是UTF-8格式的，程式就會拋出異常。FileInputStream fileInputStream=new  FileInputStream(file);DataInputStream dataInputStream=new DataInputStream(fileInputStream);  //byte [] b2=new byte[1024*120];  //int len=dataInputStream.read(b2); //按位元組讀取剩餘的內容 // System.out.println(new String(b2,0,len));System.out.println(dataInputStream.readUTF());               dataInputStream.close();               fileInputStream.close();}} catch (Exception e) {// TODO: handle exception}}/** * 緩衝流 * @param args */public static void main3(String[] args) {File file=new File("c:\\22ss.txt");try {if(!file.exists()){file.createNewFile();FileWriter fWriter=new FileWriter(file);BufferedWriter bWriter=new BufferedWriter(fWriter);String string="sfjsafjas婚紗福建\n";bWriter.write(string);bWriter.write(string);bWriter.close();fWriter.close();}else {FileReader fReader=new FileReader(file);BufferedReader bufferedReader=new BufferedReader(fReader);while(bufferedReader.ready()){String string= bufferedReader.readLine();System.err.println(string);}bufferedReader.close();fReader.close();}} catch (Exception e) {// TODO: handle exception}}/** * 字元流 * @param args */public static void main2(String[] args) {File file=new File("c:\\demo1fsdfsd.txt");try {if(!file.exists()){file.createNewFile();FileWriter fWriter=new FileWriter(file);String string="sfjsafjas婚紗福建";fWriter.write(string);fWriter.close();}else {FileReader fReader=new FileReader(file);char[] c=new char[1024];StringBuffer sBuilder=new StringBuffer();int len=fReader.read(c);while(len!=-1){fReader.read(c, 0, len);  sBuilder.append(c);len=fReader.read();System.out.println(new String(c));}}} catch (Exception e) {// TODO: handle exception}}/** * 位元組流 * @param args */public static void main1(String[] args) {File file=new File("c:\\demo1.txt");try {if(!file.exists()){file.createNewFile();FileOutputStream foStream=new  FileOutputStream(file);byte[] b=" sjd橫槊賦詩防守打法試試是".getBytes();foStream.write(b);foStream.close();}else {FileInputStream fisFileInputStream=new FileInputStream(file);byte[] b=new byte[fisFileInputStream.available()];fisFileInputStream.read(b);System.out.println(new String(b));fisFileInputStream.close();}} catch (IOException e) {// TODO: handle exceptionSystem.err.println(e.getMessage());}}}

　　

java 檔案讀寫