合并流/SequenceInputStream

Posted 2020-08-30

合并流/SequenceInputStream

 可以把如 a.txt b.txt c.txt等多个文件复制到d.txt文件

构造方法:

SequenceInputStream(Enumeration e)

 

Enumeration是Vector中的一个方法的返回值类型

Enumeration<E> elements()

 

代码

package cn.idcast2;

import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.SequenceInputStream;
import java.util.Enumeration;
import java.util.Vector;

/*
 * 需求：把Day1.java、Day102.java、Day103.java复制到d.txt里。
 * 
 */
public class SequenceInputStreamdemo {
	public static void main(String[] args) throws IOException {
		Vector<InputStream> v = new Vector<InputStream>();
		InputStream ips1 = new FileInputStream("Day1.java");
		InputStream ips2 = new FileInputStream("Day102.java");
		InputStream ips3 = new FileInputStream("Day103.java");
		v.add(ips1);
		v.add(ips2);
		v.add(ips3);
		Enumeration<InputStream> en = v.elements();
		SequenceInputStream sis = new SequenceInputStream(en);
		BufferedOutputStream bos = new BufferedOutputStream(
				new FileOutputStream("d.txt"));
		byte[] bys = new byte[1024];
		int len = 0;
		while ((len = sis.read(bys)) != -1) {
			bos.write(bys, 0, len);
		}
		sis.close();
		bos.close();

	}
}