整合输入流

来源：互联网发布：php安装教程 linux 编辑：程序博客网时间：2024/06/05 19:34

/**
   * @param args
   * 整合两个输入流
   * SequenceInputStream(InputStream s1, InputStream s2)
   * 整合多个输入流
   * SequenceInputStream(Enumeration<? extends InputStream> e)
   * @throws IOException
   */
   public static void main(String[] args) throws IOException {
       //demo1();
       //demo2();
       FileInputStream fis1 = new FileInputStream("a.txt");
       FileInputStream fis2 = new FileInputStream("b.txt");
       FileInputStream fis3 = new FileInputStream("c.txt");

       Vector<FileInputStream> v = new Vector<>();                   //创建集合对象
       v.add(fis1);                                               //将流对象存储进来
       v.add(fis2);
       v.add(fis3);

       Enumeration<FileInputStream> en = v.elements();
       SequenceInputStream sis = new SequenceInputStream(en);       //将枚举中的输入流整合成一个
       FileOutputStream fos = new FileOutputStream("d.txt");

       int b;
       while((b = sis.read()) != -1) {
           fos.write(b);
       }

       sis.close();
       fos.close();
   }

   public static void demo2() throws FileNotFoundException, IOException {
       FileInputStream fis1 = new FileInputStream("a.txt");
       FileInputStream fis2 = new FileInputStream("b.txt");
       SequenceInputStream sis = new SequenceInputStream(fis1, fis2);
       FileOutputStream fos = new FileOutputStream("c.txt");

       int b;
       while((b = sis.read()) != -1) {
           fos.write(b);
       }

       sis.close();                   //sis在关闭的时候,会将构造方法中传入的流对象也都关闭
       fos.close();
   }

   public static void demo1() throws FileNotFoundException, IOException {
       FileInputStream fis1 = new FileInputStream("a.txt");       //创建字节输入流关联a.txt
       FileOutputStream fos = new FileOutputStream("c.txt");       //创建字节输出流关联c.txt

       int b1;
       while((b1 = fis1.read()) != -1) {                           //不断的在a.txt上读取字节
           fos.write(b1);                                           //将读到的字节写到c.txt上
       }
       fis1.close();                                               //关闭字节输入流

       FileInputStream fis2 = new FileInputStream("b.txt");
       int b2;
       while((b2 = fis2.read()) != -1) {
           fos.write(b2);
       }

       fis2.close();
       fos.close();
   }

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