马士兵J2SE-第八章-流

来源：互联网发布：匿名发短信软件编辑：程序博客网时间：2024/06/04 23:25

访问文件

package com.zzk.test;import java.io.*;public class test {public static void main(String[] args) {int b=0;FileInputStream in=null;try {in=new FileInputStream("D:\\test\\a\\zzk.txt");}catch (FileNotFoundException e) {System.out.println("找不到指定文件");System.exit(-1);}try {long num=0;while((b=in.read())!=-1) {System.out.print((char)b);num++;}in.close();System.out.println();System.out.println("共读取了"+num+"个字节");}catch(IOException e1) {System.out.println("文件读取错误");System.exit(-1);}}}

输出：

a123123ewawewaq123
asd
ads
adsd
共读取了31个字节

文件复制：

package com.zzk.test;//文件复制import java.io.*;public class test {  public static void main(String[] args) {  int b = 0;  FileInputStream in = null;  FileOutputStream out = null;  try {    in = new FileInputStream("d:/test/a/zzk.txt");    out = new FileOutputStream("d:/test/a/zzk1.txt");    while((b=in.read())!=-1){      out.write(b);    }    in.close();     out.close();  } catch (FileNotFoundException e2) {    System.out.println("找不到指定文件"); System.exit(-1);  } catch (IOException e1) {    System.out.println("文件复制错误"); System.exit(-1);  }  System.out.println("文件已复制");  }}

import java.io.*;public class TestFileReader {  public static void main(String[] args) {    FileReader fr = null;     int c = 0;    try {      fr = new FileReader("d:\\share\\java\\io\\TestFileReader.java");      int ln = 0;      while ((c = fr.read()) != -1) {        //char ch = (char) fr.read();        System.out.print((char)c);        //if (++ln >= 100) { System.out.println(); ln = 0;}      }      fr.close();    } catch (FileNotFoundException e) {      System.out.println("找不到指定文件");    } catch (IOException e) {      System.out.println("文件读取错误");    }  }}

import java.io.*;public class TestFileWriter {  public static void main(String[] args) {    FileWriter fw = null;    try {      fw = new FileWriter("d:\\bak\\unicode.dat");      for(int c=0;c<=50000;c++){        fw.write(c);      }      fw.close();    } catch (IOException e1) {    e1.printStackTrace();      System.out.println("文件写入错误");      System.exit(-1);    }  }}