import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

public class Test {

	public static void main(String[] args) {

		int b = 0;

		long num = 0;

		FileInputStream in = null;

		try{

			in = new FileInputStream("E:/eclipse projiect/data.txt");

		}catch(FileNotFoundException e){

			System.out.println("指定文件不存在");

			System.exit(-1);

		}

		try {

			while((b = in.read()) != -1){

				System.out.print((char)b +" ");

				num++;

				if(num/5 == 0){

					System.out.println();

				}

			}

			in.close();

			System.out.println("一共读取了多少个字节："+num); //该方法不认识字符

		} catch (IOException e) {

			System.out.println("指定文件读取错误");

			System.exit(-1);

		}

	}

}

class Test{

	public static void main(String[] args) {

		int b = 0;

		int c = 0;

		FileInputStream in = null;

		FileOutputStream out = null;

		try {

			in = new FileInputStream("E:/eclipse projiect/data.txt");

			out = new FileOutputStream("E:/eclipse projiect/data1.txt"); // FileOutputStream 如果没有这个文件，自动的会帮你建一个

			try {

				while((b = in.read()) != -1){

					out.write(b);

				}

				in.close();

				out.close();

			} catch (IOException e) {

				System.out.println("文件复制错误");

				System.exit(-1);

			}

		} catch (FileNotFoundException e) {

			System.out.println("指定文件不存在");

			System.exit(-1);

		}

		System.out.println("文件复制成功");

	}

}

class Test {

	public static void main(String[] args) {

		FileReader fr = null;

		int c = 0;

		int len = 0;

		try {

			fr = new FileReader("E:/eclipse projiect/data2.txt");

			while((c = fr.read()) != -1){ // 一个字符一个字符的读

				System.out.print((char)c);

			}

		} catch (FileNotFoundException e) {

			e.printStackTrace();

		} catch(IOException e){

			e.printStackTrace();

		}

	}

}

import java.io.*;

class Test {

	public static void main(String[] args) {

		FileWriter fw = null;

		try {

			fw = new FileWriter("E:/eclipse projiect/data3.txt"); // 如果这个文件不存在，它会帮我们建一个

			for(int c=0;c<5000;c++){

				fw.write((char)c); // 将这个字符写进去，char 2 个字节，最大到25536.相当于Unicode把大多数国家的字符都写进去了.

			}                // char 2 个字节，代表了全世界大多数国家的文字

			fw.close();

		} catch (Exception e) {

			System.out.println("文件写入错误");

			System.exit(-1);

		}

		System.out.println("文件写入成功");

	}

}