java 文件讀寫
阿新 • • 發佈:2017-11-20
字節流 就會 brush not line 程序 sdf highlight write
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 { // 註意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序出現異常。 // 如首先寫入文件用的是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,程序就會拋出異常。 FileInputStream fileInputStream=new FileInputStream(file); DataInputStream dataInputStream=new DataInputStream(fileInputStream); //byte [] b2=new byte[1024*120]; //int len=dataInputStream.read(b2); //按字節讀取剩余的內容 // System.out.println(new String(b2,0,len)); System.out.println(dataInputStream.readUTF()); dataInputStream.close(); fileInputStream.close(); } } catch (Exception e) { // TODO: handle exception } } /** * 緩存流 * @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 } } /** * 字符流 * @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 } } /** * 字節流 * @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 exception System.err.println(e.getMessage()); } } }
java 文件讀寫