javaio包内常用类及方法.doc

java.io.*包内常用类及方法杜伟健版权声明：本资料只免费提供给2011级软件7班同学使用，其他任何未经授权的人擅自传播、印制，均视为侵权行为。一、文本文件（Text File）1、输出（output）类 (to the file)（1）PrintWriter注意：不可以接文件名，可通过套用FileOutputStream来实现。例如PrintWriter outputStream =new PrintWriter(new FileOutputStream(out.txt); 常用方法：print()、println()：写文件 ，close()：保存并关闭文件。（2）FileOutputStream 注意：可以接文件名。例：public static void main(String args) PrintWriter outputStream = null; try outputStream = new PrintWriter(new FileOutputStream(out.txt); catch(FileNotFoundException e) System.out.println(Error opening the file out.txt.); System.exit(0); System.out.println(Enter three lines of text:);String line = null;int count; for (count = 1; count = 0) System.out.println(n); n = inputStream.readInt(); System.out.println(End of reading from file.); inputStream.close(); catch(IOException e) System.out.println(); 三、注意点1、每个read方法都抛出IOException。2、read到文章结束会抛出EOFException。3、读取错误数据类型，不会出现错误信息。例：try DataInputStream inputStream =new DataInputStream(new FileInputStream(numbers.dat); int n; System.out.println(Reading ALL the integers); System.out.println(in the file numbers.dat.); try while (true) n = inputStream.readInt(); System.out.println(n); catch(EOFException e) System.out.println(End of reading from file.); inputStream.close(); catch(FileNotFoundException e) System.out.println(Cannot find file numbers.dat.); catch(IOExcept