[Java] IO-01 FileInputStream / FileOutputStream / FileReader / FileWriter

package com.bjsxt.chap8.IO;

import java.io.*;

public class TestFileInputStream {
    public static void main(String[] args) {
        int b = 0;
        FileInputStream in = null;   // java.io.InputStream  -  java.io.FileInputStream

        try {
            in = new FileInputStream(
                    "D:\Java\JavaProjects\MyPractice\src\com\bjsxt\chap8\IO\TestFileInputStream.java");
        } 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) { //  int read() 从此输入流中读取一个数据字节。 
                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);
        }
    }
}

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.FileWriter;
import java.io.IOException;

public class TestFileWriter {
  public static void main(String[] args) {
    FileWriter fw = null;
    try {
      fw = new FileWriter("D:\1.txt");
      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);
    }
  }
}