ObjectOutputStream类writeDouble()方法 (ObjectOutputStream Class writeDouble() method)

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

  java.io包中提供了writeDouble()方法 。

• writeDouble() method is used to write the given 8 bytes (i.e. 64 bit) double value.

  writeDouble()方法用于写入给定的8字节(即64位)双精度值。

• writeDouble() 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.

  writeDouble()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。

• writeDouble() method may throw an exception at the time of writing double.

  writeDouble()方法在编写double时可能会引发异常。

  IOException: This exception may throw when getting any input/output error while writing to the output stream.

  IOException ：在写入输出流时遇到任何输入/输出错误时，可能引发此异常。

Syntax:

句法：

    public void writeDouble(double value);

Parameter(s):

参数：

• double value – represents the double value to be written.

  double value –表示要写入的double值。

Return value:

返回值：

The return type of the method is void, it returns nothing.

该方法的返回类型为void ，不返回任何内容。

Example:

例：

// Java program to demonstrate the example 
// of void writeDouble(double value)
// method of ObjectOutputStream
import java.io.*;
public class WriteDoubleOfOOS {
public static void main(String[] args) throws Exception {
// Instantiates ObjectOutputStream , ObjectInputStream 
// FileInputStream and FileOutputStream
FileOutputStream file_out_stm = new FileOutputStream("D:\\includehelp.txt");
ObjectOutputStream obj_out_stm = new ObjectOutputStream(file_out_stm);
FileInputStream file_in_stm = new FileInputStream("D:\\includehelp.txt");
ObjectInputStream obj_in_stm = new ObjectInputStream(file_in_stm);
// By using writeDouble() method is to
// write the double to the stream		
obj_out_stm.writeDouble(10.0);
obj_out_stm.writeDouble(20.0);
obj_out_stm.writeDouble(30.0);
obj_out_stm.writeDouble(40.0);
obj_out_stm.flush();
// By using readDouble() method is to 
// read the double 
for (int i = 0; i < 4; ++i) {
double d = obj_in_stm.readDouble();
System.out.println("obj_in_stm.readDouble(): " + d);
}
// By using close() method is to 
// close all the streams 
System.out.println("Stream Shutdown...");
file_in_stm.close();
file_out_stm.close();
obj_in_stm.close();
obj_out_stm.close();
}
}

Output

输出量

obj_in_stm.readDouble(): 10.0
obj_in_stm.readDouble(): 20.0
obj_in_stm.readDouble(): 30.0
obj_in_stm.readDouble(): 40.0
Stream Shutdown...

翻译自: https://www.includehelp.com/java/objectoutputstream-writedouble-method-with-example.aspx