装饰模式案列(OutputStream)

使用装饰模式进行装饰OutputStream

写入文件成功

装饰类继承OutputStream类

DecorOutputStream

package com.wbg.springRedis.decorator;

import java.io.IOException;
import java.io.OutputStream;

public class DecorOutputStream extends OutputStream {
    private OutputStream os;
    private double index = 0;
    private double sum = 0;
    public DecorOutputStream(OutputStream os) {
        this.os = os;
    }

    @Override
    public void write(int b) throws IOException {
        this.index++;
        double Progress = this.index/this.sum*100;
        System.out.println("写入进度"+(int)Progress+"%");
            os.write(b);
    }

    @Override
    public void write(byte[] b) throws IOException {
        this.sum = b.length;
        System.out.println("开始写入文件");
        super.write(b);
        System.out.println("写入文件完毕");
    }
}

测试：

 public static void main(String[] args) throws IOException {
        FileOutputStream stream = new FileOutputStream(new File("g:/ccc.txt"));
        DecorOutputStream los = new DecorOutputStream(stream);
        los.write("hello, word!".getBytes());
        los.close();
    }