Java中的IO字节流

 关闭流的顺序：

　　* 当A依赖B的时候先关闭A，再关闭B
　　* 带缓冲的流最后关闭的时候会执行一次flush

ByteArrayInputStream ：是字节数组输入流，作用是把字节串(或叫字节数组)变成输入流的形式

package object.io;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class ByteArrayStream {

    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
        byte[] b=new byte[]{'a','b','c'};
        //将字节输入转成流
        ByteArrayInputStream input=new ByteArrayInputStream(b);
        ByteArrayOutputStream output=new ByteArrayOutputStream();
        FileOutputStream fileOut=new FileOutputStream("D:\Program Files (x86)\io\ByteArray.txt");
        int length;
        while((length=input.read())!=-1){
            fileOut.write(length);
        }
        //将缓冲区的内容刷新到输出流
        output.writeTo(fileOut);
        input.close();
        output.close();
        fileOut.close();
    }
    

}

SequenceInputStream ：将多个文件合并成一个文件

package object.io;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.SequenceInputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;


public class SequenceStream {
    
    //将多个文件合并到一个文件
    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
    
        FileInputStream f1=new FileInputStream("D:\Program Files (x86)\io\sequence1.txt");
        FileInputStream f2=new FileInputStream("D:\Program Files (x86)\io\sequence2.txt");
        FileInputStream f3=new FileInputStream("D:\Program Files (x86)\io\sequence3.txt");
        List<FileInputStream> list=new ArrayList<FileInputStream>();
        list.add(f1);
        list.add(f2);
        list.add(f3);
        
        //将集合转换成枚举类型
        Enumeration<FileInputStream> e=Collections.enumeration(list);
        
        //接收的是枚举类型，如上图所示
        SequenceInputStream s=new SequenceInputStream(e);
        
        FileOutputStream outputStream=new FileOutputStream("D:\Program Files (x86)\io\sequence4.txt");
        int length;
        while((length=s.read())!=-1){
            outputStream.write(length);
        }
        f1.close();
        f2.close();
        f3.close();
        s.close();
        outputStream.close();
    }

}

BufferedInputStream ：缓冲字节输入流，是一个高级流(处理流)，与其他低级流配合使用，将其他流包装起来。效率高

BufferedInputStream ：同BufferedInputStream 

package object.io;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class BufferStream {
    public static void main(String[] args) throws IOException {
        FileInputStream input=new FileInputStream("D:\Program Files (x86)\io\bufferStream1.txt");
        BufferedInputStream binput=new BufferedInputStream(input);
        FileOutputStream output=new FileOutputStream("D:\Program Files (x86)\io\bufferStream2.txt");
        BufferedOutputStream boutput=new BufferedOutputStream(output);
        int length;
        while((length=binput.read())!=-1){
            boutput.write(length);
        }
        //将缓冲区的内容刷新到文件
        boutput.flush();
        input.close();
        binput.close();
        output.close();
        boutput.close();
    }
}