输入输出流

package Text;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class IO
{

    public static void main(String[] args) throws IOException
    {
        long begin = System.currentTimeMillis(); 
        SrSc2();
        long end = System.currentTimeMillis() - begin;             
        System.out.println("耗时：" + end + "毫秒");        
    }
    //挨个字节读取输入
    private static void SrSc1() throws IOException
    {
        //判断文件是否存在
        File a = new File("E:/Text.txt");
        if(a.exists())
        {

        FileInputStream fIn = new FileInputStream("E:\\Text.txt");
        FileOutputStream fOut = new FileOutputStream("E:\\复制文件1.txt");
        
        int temp = 0;
        while(temp != -1)
        {
            temp = fIn.read();
            fOut.write(temp);
        }
        //关闭输入输出流
        fIn.close();
        fOut.close();
        
        //打印读取成功信息
        System.out.println("挨个字节复制文件成功");
        
        }
        else
        {
            //判断文件如果不存在，打印提示信息
            System.out.println("文件不存在");
        }
    }
    //用数组批量复制
    private static void SrSc2() throws IOException
    {
        //判断文件是否存在
        File a = new File("E:/Text.txt");
        if(a.exists())
        {

        FileInputStream fIn = new FileInputStream("E:\\Text.txt");
        FileOutputStream fOut = new FileOutputStream("E:\\复制文件2.txt");
        
        //获取文件长度
        int n = fIn.available();
        
        //创建一个可以读取的数组
        byte[] b = new byte[n];
        fIn.read(b);        
        
        //复制
        fOut.write(b);
        
        //关闭输入输出流
        fIn.close();
        fOut.close();
        
        //打印读取成功信息
        System.out.println("批量字节复制成功");
        
        }
        else
        {
            //判断文件如果不存在，打印提示信息
            System.out.println("文件不存在");
        }
    }
}

package Text;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class FileIO 
{
    public static void main(String[] args) throws IOException
    {
        long begin = System.currentTimeMillis(); 
        Reade2();
        long end = System.currentTimeMillis() - begin;             
        System.out.println("耗时：" + end + "毫秒");
        
    }

    private static void Write() throws IOException
    {
            //创建一个文件、实例化对象
            FileOutputStream fo = new FileOutputStream("E:/Text.java");
            
            //输入需要写入的文档内容
            String str1 = "China中国188";
            String str2 = "Name:伯乐在此-123";
            String str3 = "这是个什么鬼";
                    
            //关联文档内容
            byte[] b1 = str1.getBytes();
            byte[] b2 = str2.getBytes();
            byte[] b3 = new byte[100];
            b3 = str3.getBytes();
            
            //获取文件长度
            int len1 = b1.length;
            int len2 = b2.length;
            int len3 = b3.length;
            
            //写入文档内容1
            fo.write(str1.getBytes());
            
            //写入文档内容2
            int i2 = 0;
            fo.write(b2, i2, b2.length);
            
            //写入文档内容3
            int i3 = 0;
            while(i3 < b3.length)
            {
                fo.write(b3[i3]);
                i3++;
            }
            
            //关闭
            fo.close();
    }
    private static void Reade1() throws IOException
    {                
        //创建对象、关联需要读取的文件
        FileInputStream fin1 = new FileInputStream("E:/Text.txt");
                
        //获取文件长度
        int n = fin1.available();    
                
        //创建一个可读取的数组
        byte[] b = new byte[n];
        fin1.read(b);
            
        //关闭
        fin1.close();
                        
        //将字节数组转成字符串输出
        System.out.println(new String(b));
    }
    private static void Reade2() throws IOException
    {
        //创建对象、关联需要读取的文件
        FileInputStream fin2 = new FileInputStream("E:/Text.txt");
            
        //获取文本长度
        File f = new File("E:/Text.txt");
        int len = (int)f.length();
        
        for(int i=0;i<len;i++)
        {
            int rDate = fin2.read();
            if(-1 != rDate)
            {
                System.out.print((char)rDate);
            }
        }    
        
        //关闭
        fin2.close();
    }
}