java学习笔记之FileReader FileWriter

Stream是按字节的，Reader Writer是按字符的

Reader

举个栗子：

package io;

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");
    }

  }
}

Writer

package io;

import java.io.*;
public class TestFileWriter {
  public static void main(String[] args) {
    FileWriter fw = null;
    try {
      fw = new FileWriter("d:/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);
    }
  }
}

疑惑：write一个int，计算机内部到底是怎样write的呢，肯定不是写成数据，而是写成流，流是怎样写的呢，写int还是写char