Java ObjectInputStream readFloat（）方法与示例

ObjectInputStream类readFloat()方法 (ObjectInputStream Class readFloat() method)

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

  readFloat()方法在java.io包中可用。

• readFloat() method is used to read 4 bytes (i.e. 32 bit) of float value from this ObjectInputStream stream.

  readFloat()方法用于从此ObjectInputStream流中读取4个字节(即32位)的float值。

• readFloat() 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.

  readFloat()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。

• readFloat() method may throw an exception at the time of reading float.

  readFloat()方法在读取float时可能会引发异常。

  • IOException: This exception may throw when getting any input/output error while performing.IOException ：在执行过程中遇到任何输入/输出错误时，可能引发此异常。
  • EOFException: This exception may throw when this stream has reached its end of the file.EOFException ：当此流到达文件末尾时，可能引发此异常。

Syntax:

句法：

    public float readFloat();

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 float, it returns the 4 bytes float value read.

该方法的返回类型为float ，它返回读取的4个字节的float值。

Example:

例：

// Java program to demonstrate the example 
// of float readFloat() method of ObjectInputStream

import java.io.*;

public class ReadFloatOfOIS {
 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 writeFloat() method is to write
  // float to the obj_out_stm stream
  obj_out_stm.writeFloat(10.0f);
  obj_out_stm.writeFloat(20.0f);
  obj_out_stm.writeFloat(30.0f);
  obj_out_stm.writeFloat(40.0f);

  obj_out_stm.flush();

  while (obj_in_stm.available() > 0) {
   // By using readFloat() method is to read
   //  double from the obj_in_stm
   float val = (float) obj_in_stm.readFloat();
   System.out.println("obj_in_stm.readFloat(): " + val);
  }

  // By using close() method is to 
  // close all the streams 
  file_in_stm.close();
  file_out_stm.close();
  obj_in_stm.close();
  obj_out_stm.close();
 }
}

Output

输出量

obj_in_stm.readFloat(): 10.0
obj_in_stm.readFloat(): 20.0
obj_in_stm.readFloat(): 30.0
obj_in_stm.readFloat(): 40.0

翻译自: https://www.includehelp.com/java/objectinputstream-readfloat-method-with-example.aspx