package com.study02;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
 * 文件字节输出流
 * 1.创建源
 * 2.选择流
 * 3.操作(写出内容)
 * 4.释放资源
 * @author Administrator
 *
 */
public class IOtest04 {
	public static void main(String[] args) {
		File src = new File("aaa.txt");
		OutputStream os = null;
		try {
			os = new FileOutputStream(src,true);//true:在原来的基础上写入;false:清空原来的数据,重新写入
			
			String msg = new String("IO is so easy!");
			byte[] datas = msg.getBytes();//字符串-->字节数组(编码)
			os.write(datas,0,datas.length);
			os.flush();
			
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}finally {
			if (os!=null) {
				try {
					os.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			
		}
	}
}
原文:https://www.cnblogs.com/LuJunlong/p/11747765.html