你可以试试仙人掌:

new LengthOf(new TeeInput(array, new File("a.txt"))).value();

详情:http://www.yegor256.com/2017/06/22/object-oriented-input-output-in-cactoos.html

我知道它是用InputStream完成的

实际上，你会写入一个文件输出…

这是一个程序，我们正在读取和打印数组的字节偏移量和长度使用String Builder和写入数组的字节偏移量长度到新文件。

在这里输入代码

import java.io.File;   
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;        

//*This is a program where we are reading and printing array of bytes offset and length using StringBuilder and Writing the array of bytes offset length to the new file*//     

public class ReadandWriteAByte {
    public void readandWriteBytesToFile(){
        File file = new File("count.char"); //(abcdefghijk)
        File bfile = new File("bytefile.txt");//(New File)
        byte[] b;
        FileInputStream fis = null;              
        FileOutputStream fos = null;          

        try{               
            fis = new FileInputStream (file);           
            fos = new FileOutputStream (bfile);             
            b = new byte [1024];              
            int i;              
            StringBuilder sb = new StringBuilder();

            while ((i = fis.read(b))!=-1){                  
                sb.append(new String(b,5,5));               
                fos.write(b, 2, 5);               
            }               

            System.out.println(sb.toString());               
        }catch (IOException e) {                    
            e.printStackTrace();                
        }finally {               
            try {              
                if(fis != null);           
                    fis.close();    //This helps to close the stream          
            }catch (IOException e){           
                e.printStackTrace();              
            }            
        }               
    }               

    public static void main (String args[]){              
        ReadandWriteAByte rb = new ReadandWriteAByte();              
        rb.readandWriteBytesToFile();              
    }                 
}                

O/P在控制台:fghij

O/P在新文件:cdefg

使用java.nio.file的另一个解决方案:

byte[] bytes = ...;
Path path = Paths.get("C:\\myfile.pdf");
Files.write(path, bytes);

没有任何库:

try (FileOutputStream stream = new FileOutputStream(path)) {
    stream.write(bytes);
}

谷歌番石榴:

Files.write(bytes, new File(path));

使用Apache Commons:

FileUtils.writeByteArrayToFile(new File(path), bytes);

所有这些策略都要求您在某个时刻捕获IOException。

同样从Java 7开始，一行Java .nio.file. files:

Files.write(new File(filePath).toPath(), data);

其中data是字节[]，filePath是字符串。您还可以使用StandardOpenOptions类添加多个文件打开选项。添加投掷或环绕尝试/接。