JAVA学习笔记(三十六)- 文件的拆分和合并

文件的拆分和合并

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;

/*
 * 文件的拆分和合并
 */
public class Test07 {
    public static void main(String[] args) throws IOException {
        // splitFile();
        mergeFile2();
    }

    // 拆分文件：一个输入流、多个输出流
    public static void splitFile() throws IOException {
        FileInputStream fis = new FileInputStream("D:\\Java\\itany.bmp");
        FileOutputStream fos = null;
        byte[] buffer = new byte[1024 * 1024];// 每次读取1M
        int num;
        int count = 1;
        while ((num = fis.read(buffer)) != -1) {
            fos = new FileOutputStream("D:\\Java\\splitFiles\\itany"
                    + (count++) + ".part");
            fos.write(buffer, 0, num);
            fos.flush();
            fos.close();
        }
        fis.close();
        System.out.println("拆分文件成功！");
    }

    // 合并文件：一个输出流、多个输入流
    public static void mergeFile() throws IOException {
        FileInputStream fis1 = new FileInputStream(
                "D:\\Java\\splitFiles\\itany1.part");
        FileInputStream fis2 = new FileInputStream(
                "D:\\Java\\splitFiles\\itany2.part");
        FileInputStream fis3 = new FileInputStream(
                "D:\\Java\\splitFiles\\itany3.part");
        FileOutputStream fos = new FileOutputStream(
                "D:\\Java\\splitFiles\\itany.bmp");
        byte[] buffer = new byte[1024 * 1024];
        int num;
        while ((num = fis1.read(buffer)) != -1) {
            fos.write(buffer, 0, num);
        }
        while ((num = fis2.read(buffer)) != -1) {
            fos.write(buffer, 0, num);
        }
        while ((num = fis3.read(buffer)) != -1) {
            fos.write(buffer, 0, num);
        }
        fos.flush();
        fos.close();
        fis1.close();
        fis2.close();
        fis3.close();
        System.out.println("合并文件成功！");
    }

    // SequenceInputStream 表示其他输入流的逻辑串联
    public static void mergeFile2() throws IOException {
        FileOutputStream fos = new FileOutputStream(
                "D:\\Java\\splitFiles\\itany.bmp");

        //定义一个Vector集合，保存InputStream
        Vector<InputStream> v=new Vector<InputStream>();
        for(int i=1;i<=3;i++){
            v.add(new FileInputStream("D:\\Java\\splitFiles\\itany"+i+".part"));
        }
        //获取Enumeration实例
        Enumeration<InputStream> e=v.elements();
        //定义一个SequenceInputStream
        SequenceInputStream sis=new SequenceInputStream(e);
        byte[] buffer=new byte[1024];
        int num;
        while((num=sis.read(buffer))!=-1){
            fos.write(buffer, 0, num);
        }
        fos.flush();
        fos.close();
        sis.close();
        System.out.println("合并文件成功！");
    }

}