DataOutputStream类的size()方法 (DataOutputStream Class size() method)

• size() method is available in java.io package.

  size()方法在java.io包中可用。

• size() method is used to return the size of this stream or in other words, we can say it returns the value of the variable counter that contains written bytes.

  size()方法用于返回此流的大小，换句话说，可以说它返回包含已写入字节的变量计数器的值。

• size() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  size()方法是一种非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。

• size() method does not throw an exception at the time of returning size.

  返回size时， size()方法不会引发异常。

Syntax:

句法：

    public final int size();

Parameter(s):

参数：

• It does not accept any parameter.

  它不接受任何参数。

Return value:

返回值：

The return type of the method is int, it returns the last value of the variable counter.

方法的返回类型为int ，它返回变量计数器的最后一个值。

Example:

例：

// Java program to demonstrate the example
// of int size() method of DataOutputStream
import java.io.*;
public class SizeOfDOS {public static void main(String[] args) throws IOException {InputStream is_stm = null;
DataInputStream dis_stm = null;
FileOutputStream fos_stm = null;
DataOutputStream dos_stm = null;
byte[] b_arr = {12,
20,
45,
98,
75,
69,
30,
58,
47,
61,
83,
55
};
try {// Instantiate FileInputStream,
// DataInputStream, FileOutputStream
// and DataOutputStream
fos_stm = new FileOutputStream("C:\\Users\\Preeti Jain\\Desktop\\programs\\includehelp.txt");
dos_stm = new DataOutputStream(fos_stm);
is_stm = new FileInputStream("C:\\Users\\Preeti Jain\\Desktop\\programs\\includehelp.txt");
dis_stm = new DataInputStream(is_stm);
// Loop to write each byte till end
for (byte val: b_arr) {// By using write() method isto
// write a byte value to the
// DataOutputStream dos_stm
dos_stm.write(val);
}
// Loop To Read Available Data till end
while (dis_stm.available() > 0) {// By using read() method isto read
// byte from dis_stm
int in = dis_stm.read();
System.out.println("dis_stm.read(): " + in );
}
System.out.println();
// By using size() method isto return
// size of this stream
int size = dos_stm.size();
System.out.println("dos_stm.size(): " + size);
} catch (Exception ex) {System.out.println(ex.toString());
} finally {// To free system resources linked
// with these streams
if (is_stm != null)
is_stm.close();
if (dis_stm != null)
dis_stm.close();
if (dos_stm != null)
dos_stm.close();
if (fos_stm != null)
fos_stm.close();
}
}
}

Output

输出量

dis_stm.read(): 12
dis_stm.read(): 20
dis_stm.read(): 45
dis_stm.read(): 98
dis_stm.read(): 75
dis_stm.read(): 69
dis_stm.read(): 30
dis_stm.read(): 58
dis_stm.read(): 47
dis_stm.read(): 61
dis_stm.read(): 83
dis_stm.read(): 55dos_stm.size(): 12

翻译自: https://www.includehelp.com/java/dataoutputstream-size-method-with-example.aspx