将a.txt、b.txt、c.txt中的内容合并成文档d.txt

package pack;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.SequenceInputStream;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Vector;
/*
SequenceInputStream(序列流)
需求：把a.txt与b.txt 文件的内容合并。
 */
public class Demo1 {
    public static void main(String[] args) throws IOException {
        merge3();
    }
    //把三个文件合并成一个文件
    public static void merge3() throws IOException{
        //找到目标文件
        File file1 = new File("E:\\a.txt");
        File file2 = new File("E:\\b.txt");
        File file3 = new File("E:\\c.txt");
        File file4 = new File("E:\\d.txt");
        //建立对应 的输入输出流对象
        FileOutputStream fileOutputStream = new FileOutputStream(file4);
        FileInputStream fileInputStream1 = new FileInputStream(file1);
        FileInputStream fileInputStream2 = new FileInputStream(file2);
        FileInputStream fileInputStream3 = new FileInputStream(file3);
        //创建序列流对象
        Vector<FileInputStream> vector = new Vector<FileInputStream>();
        vector.add(fileInputStream1);
        vector.add(fileInputStream2);
        vector.add(fileInputStream3);
        Enumeration<FileInputStream> e = vector.elements();
        SequenceInputStream sequenceInputStream = new SequenceInputStream(e);
        //读取文件数据
        byte[] buf = new byte[1024];
        int length = 0;
        while((length = sequenceInputStream.read(buf))!=-1){
            fileOutputStream.write(buf,0,length);
        }
        //关闭资源
        sequenceInputStream.close();
        fileOutputStream.close();
    }
    //	使用SequenceInputStream合并文件。
    public static void merge2() throws IOException{
        //找到目标文件
        File inFile1 = new File("E:\\a.txt");
        File inFile2 = new File("E:\\b.txt");
        File outFile = new File("E:\\c.txt");
        //建立数据的输入输出通道
        FileOutputStream fileOutputStream = new FileOutputStream(outFile);
        FileInputStream fileInputStream1 = new FileInputStream(inFile1);
        FileInputStream fileInputStream2 = new FileInputStream(inFile2);
        //建立序列流对象
        SequenceInputStream inputStream = new SequenceInputStream(fileInputStream1,fileInputStream2);
        byte[] buf = new byte[1024];
        int length = 0 ;
        while((length = inputStream.read(buf))!=-1){
            fileOutputStream.write(buf,0,length);
        }
        //关闭资源
        inputStream.close();
        fileOutputStream.close();
    }
    //需求：把a.txt与b.txt 文件的内容合并。
    public static void merge1() throws IOException{
        //找到目标文件
        File inFile1 = new File("E:\\a.txt");
        File inFile2 = new File("E:\\b.txt");
        File outFile = new File("E:\\c.txt");
        //建立数据的输入输出通道
        FileOutputStream fileOutputStream = new FileOutputStream(outFile);
        FileInputStream fileInputStream1 = new FileInputStream(inFile1);
        FileInputStream fileInputStream2 = new FileInputStream(inFile2);
        //把输入流存储到集合中，然后再从集合中读取
        ArrayList<FileInputStream> list = new ArrayList<FileInputStream>();
        list.add(fileInputStream1);
        list.add(fileInputStream2);
        //准备一个缓冲数组
        byte[] buf = new byte[1024];
        int length = 0 ;
        for(int i = 0 ; i< list.size() ; i++){
            FileInputStream fileInputStream = list.get(i);
            while((length = fileInputStream.read(buf))!=-1){
                fileOutputStream.write(buf,0,length);
            }
            //关闭资源
            fileInputStream.close();
        }
        fileOutputStream.close();
    }
}

 

 

打开a、b、c、d三个记事本，可以发现abc中的内容合并成d中的内容。