JAVA- byte stream (first experience)

  • Output streams: the superclass OutputStream, using the output stream to a file subclass FileOutputStrean
  • Input stream: superclass InputStream, subclass of the transport stream file FileInputStream
mport java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * 字节输出输入流
 * 输出流:超类OutputStream,对文件的输出流使用子类FileOutputStrean
 * 输入流:超类InputStream,对文件的输流使用子类FileInputStream
 *@author peiren
 */
public class ByteStreamDemo {

    public static void main(String[] args) {
        out();
        in();
    }
    public static void in() {
        //1、确定目标文件
        File file =new File("/Users/a10.11.5/test/123.txt");
        try {
            //2、构建文件输入流
            InputStream in=new FileInputStream(file);
            
            byte[]bytes=new byte[1024];
            StringBuilder buf=new StringBuilder();
            int len=-1;//表示每次读取字节的长度
            //把数据读到数组中,并返回读取的字节数,当不等于-1时,表示读到数据,等于-1时表示没有读到文件
            while((len=in.read(bytes))!=-1) {
                //根据读取到的字节数组,在转换为字符串内容
                buf.append(new String(bytes));
            }
            //打印内容
            System.out.println(buf);
            //关闭输入流
            in.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }   
    public static void out(){
        //1、确定目标文件
        File file =new File("/Users/a10.11.5/test/123.txt");
        try {
            //2、构建文件输出流对象
            OutputStream out=new FileOutputStream(file,true);//true表示追加内容
            //3、输出内容
            String info="小河流水哗啦啦\r\n";//\r\n表示换行
            //4、把内容写入文件
            out.write(info.getBytes());
            //5、关闭流
            out.close();
            System.out.println("write success");
            
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

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Origin blog.csdn.net/weixin_34163741/article/details/90985275
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