package inputStream; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; public class Demo { public static void main(String[] args) { readerFile3(); // System.out.println("done"); } public static void readerFile() { //创建字节输入流的对象 InputStream in =null; /** * 字符流能办到的,字节流也能办到, * 字节流能办到的,字符流不一定能办到 * 字节流能读取图片,视频各种二进制的东西 */ try { /** * 单个字节读取的效率很低 */ in = new FileInputStream("e.txt"); int num = in.read(); System.out.println(num); System.out.println((char)num); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { if(in!=null) { try { in.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } public static void readerFile1() { //创建字节输入流的对象 InputStream in =null; try { /** * 单个字节读取的效率很低 */ in = new FileInputStream("e.txt"); byte[] bs = new byte[1024]; int len = in.read(bs); System.out.println(new String(bs,0,len)); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { if(in!=null) { try { in.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } public static void readerFile3() { //创建字节输入流的对象 InputStream in =null; try { /** * 单个字节读取的效率很低 */ in = new FileInputStream("e.txt"); byte[] bs = new byte[1024]; //这里面穿的索引为1的话,就是往索引为1的地方放数据的,索引为0的地方为0,就是什么也没有, //所以用这三个参数的构造器,输入的时候是从哪开始,输出的时候也得从哪开始 int len = in.read(bs, 1, 3); System.out.println(len); System.out.println(new String(bs,1,len)); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { if(in!=null) { try { in.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } }
Io流InputStream
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转载自www.cnblogs.com/java-jiangtao-home/p/9374967.html
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