Java(IO入出力)——txtファイルの読み取り、書き込み、コピー

import java.io.*;

public class Txt {

	public static void main(String[] args) {
		readFile();
		writeFile();
		copyFile();
	}
	
	/**
	 *   TXT    
	 */
	public static void readFile() {
		try {
			/**
			 *             ， catch       ，   throw;
			 *     close(); 
			 *              ，       ;
			 */
			FileInputStream Ins = new FileInputStream("D:\\read.txt");
			int i = Ins.read();
			while(i!=-1) {
				System.out.println("       ："+i);
				i = Ins.read();
			}
			Ins.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	/**
	 *    TXT  
	 */
	public static void writeFile() {     
		try {
			FileOutputStream fos = new FileOutputStream("D:\\write.txt");
			String str = "46346assfjfi";
			byte[] bt = str.getBytes(); //   
			fos.write(bt);	//   	
			fos.close();  //   
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	/**
	 *   TXT  
	 */
	public static void copyFile() {
		try {
			FileInputStream fis = new FileInputStream("D:\\read.txt");
			FileOutputStream fos = new FileOutputStream("D:\\copy.txt");
			
			long start = System.currentTimeMillis(); //            
			
			int len;
			while((len = fis.read()) !=-1) {
				fos.write(len);
			}
			
			long end = System.currentTimeMillis(); //            
			System.out.println("           ："+(end-start)+"  ");
			
			fis.close();  //   
			fos.close();  //   
			
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

}