文件字节流输入和输出

文件字节流的输入和输出是根据程序而言的，从程序输出到文件中的称输出流：FileOutputStream；从文件输入到程序中的称输入流：FileInputStream。

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

public class FileInOutDemo {
	// 文件字节输入定义缓冲区时用小写byte
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		// 文件输出流
		try {
			FileOutputStream fos = new FileOutputStream("D:/test.txt");
			String date = "到点了兄弟";
			try {
				fos.write(date.getBytes());
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		// 文件输入流
		FileInputStream fis = null;
		try {
			fis = new FileInputStream("D:/test.txt");
			byte[] bt = new byte[1024];
			int lon = 0;
			StringBuffer sb = new StringBuffer();
			try {
				while ((lon = fis.read(bt)) > 0) {
					sb.append(new String(bt, 0, lon));
				}
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			System.out.println(sb);

		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		/*
		 * FileInputStream fis = null; try { //得到一个输入流 fis = new
		 * FileInputStream("D:/test.txt"); //定义缓存区 1kb byte buf[] = new byte[1024];
		 * //实际读取到的字节数 int leng = 0;
		 * 
		 * StringBuffer sb = new StringBuffer();
		 * 
		 * while((leng = fis.read(buf)) > 0) { sb.append(new String(buf,0,leng)); }
		 * 
		 * System.out.println(sb); } 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(); } }
		 */

	}

}