Which constructs a DataOutputStream？（）A、 New dataOutputStream（“out.txt”）；B、 New dataOutputStream（new file（“out.txt”））；C、 New dataOutputStream（new writer（“out.txt”））；D、 New dataOutputStream（new FileWriter（“out.txt”））；E、 New dataOutputStream（new OutputStre

A、InputStream in=new FileReader(“file.txt”)

B、InputStream in=new FileInputStream(“file.txt”)

C、InputStream in=new InputStreamFileReader (“file.txt”,“read”)

D、FileInputStream in=new FileReader(new File(“file.txt”))

阅读下面写文件的程序 import java. io. *; public class WriteFile{ public static void main(String[]A) { int[]myArray={10,20,30,40}; try{ FileOutputStream f=new FlieOutStream("ints. dat"); DataOutputStream______=new DataOutputStream(f); for(int i=0; i＜myArray. length; i ++) dos. writeInt(myArray[i]); dos. close(); System. out. prinfln("Have written binary file ints. dat"); } catch(IOException ioe){ System. out. println("IO Exception"); } } 在程序下画线处填入的正确选项是

A．myArray

B．dos

C．ioe

D．ints

下面创建一个新文件对象方法错误的是( )。

A．File myFile; myFile=new File("mulu/file");

B．File myFile=new File();

C．myFile=new FileC/mulu","filel");

D．File myDir=new file("/mulu"); myFile=new File(Dir, "filer');

（ 20 ） 下列程序的功能是将一个整数数组写入二进制文件 。 在程序的下划线处应填入的选项是

import java.io.*;

public class XieShuzu{

public static void main(String[] a){

int [] myArray={10,20,30,40};

try{

DataOutputStream dos=

new DataOutputStream(new FileOutputStream( " ints.dat " ));

for(int i=0;i<myArray.lenth;i++)

dos. _______(myArray[i]);

dos.close();

System.out.println( " 已 经 将 整 数 数 组 写 入 二 进 制 文 件 ：

ints.dat " );

}catch(IOException ioe)

{System.out.println( " IO Exception " );}

}

}

A ） writeArray

B ） writeByte

C ） writeInt

D ） writeDouble

A.Compilation fails.

B.Nothing is added to the file system.

C.Only a new file is created on the file system.

D.Only a new directory is created on the file system.

E.Both a new file and a new directory are created on the file system.

A. mv /old_dir/file /new_dir

B. mv -p /old_dir/file /new_dir

C. mv -k /old_dir/file /new_dir

D. mv /old_dir/file /new_dir/new_file

阅读下面程序

import java.io.*;

public class ByteStream Test{

public static void main(String[] a){

int[] myArray = {10,20.30,40};

try{

DataOutputStream dos = new DataOutputStream

(new _________________( " ints.dat " ));

for (int i=0;i<myArray.length;i++)

dos.writeInt(myArray[i] ) ;

dos.close();

S ystem.out.println( " Have written binary file ints.dat " );

}

catch (IOException ioc){

System.out.println( " IO Exception " );

}

}

}

为保证程序正确运行，在程序中下划线处应填入的代码是

A)FileOutputStream

B)ByteArrayOutputStream

C)BufferedOutputStream

D)FileWriter