java文件读写（输入输出流）

/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */package filetest;import java.io.*;/** * * @author X */public class FileTest {    /**     * @param args the command line arguments     */    public static void main(String[] args) {        // TODO code application logic here        try        {            /*三种读文件的方式              FileReader fr = new FileReader("src/filetest/FileTest.java");              int ch = 0;                  while((ch = fr.read())!=-1 ){                      System.out.print( (char)ch );                  }                          InputStream is = new FileInputStream(new File("src/filetest/FileTest.java"));              InputStreamReader fr = new InputStreamReader(is);              int ch = 0;                while((ch = fr.read())!=-1 ){                    System.out.print((char)ch);                }                        BufferedReader br = new BufferedReader(new FileReader("src/filetest/FileTest.java"));              String data = br.readLine();//一次读入一行，直到读入null为文件结束              while( data!=null){                    System.out.println(data);                    data = br.readLine(); //接着读下一行              }            */                      //简单写文件，除此以外，还有RandomAccessFile          /*            FileWriter fw = new FileWriter("testdata.txt");                String s = "hello world";                fw.write(s,0,s.length());                fw.flush();                OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream("testdata1.txt"));                osw.write(s,0,s.length());                osw.flush();                PrintWriter pw = new PrintWriter(new OutputStreamWriter(new FileOutputStream("testdata2.txt")),true);                pw.println(s);                fw.close();                osw.close();                pw.close();            */            BufferedWriter writer  = new BufferedWriter(new FileWriter("testdata.txt"));            String line = "hello world!";            writer.write(line);            writer.flush();                writer.close();                     }        catch(IOException e)        {            System.out.println("file read error!");        }    }    }