FileInputStream文件字节输入流程序

第一种：.read() 一次读一个字节，返回值类型是int，方法读取硬盘访问次数太频繁。缺点：效率低，伤硬盘

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


public class FileInputStreamTest {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        FileInputStream fis = null;
        try {
            fis = new FileInputStream("C:\\update.txt");
            int temp;
            while((temp=fis.read())!=-1)
            {
                System.out.print(temp);
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally{
            try {
                fis.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}

执行结果：

678269658469327980847377739069756989321211019711432797832846566766932991061021001161161310131073788369828432737884793284656676693299106102100116116328773847232756989326132121101971141310973787073766932349958929910610210048504611612011634131013106882798032798084737773906975698932121101971143279783284656676693299106102100116116

 

第二种：使用.read(byte[] bytes) 一次读取多个字节。该方法执行结束后，返回值是该次读到的字节数，读不到则返回-1

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


public class FileInputStreamTest01 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        FileInputStream fis = null;
        try {
            fis = new FileInputStream("C:\\update.txt");
            byte[] bs = new byte[10];        
            int temp;
            while((temp=fis.read(bs))!=-1)
            {
//                System.out.println(temp);
                String s = new String(bs,0,temp);    //把数组中的元素全部转换成字符串打印出来
                System.out.print(s);
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally{
            try {
                fis.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }    
    }
}

执行结果：

CREATE OPTIMIZEKEY year ON TABLE cjfdtt

INSERT INTO TABLE cjfdtt WITH KEY = year
    INFILE "c:\cjfd02.txt"

DROP OPTIMIZEKEY year ON TABLE cjfdtt